What are dermatomes and myotomes. How do they relate to the nervous system. Why are dermatomes and myotomes important for medical diagnosis. What are the key dermatome patterns on the body. How do doctors test dermatomes and myotomes. What conditions can affect dermatomes and myotomes.

The Basics of Dermatomes and Myotomes

Dermatomes and myotomes are crucial concepts in understanding how nerves are distributed throughout the human body. But what exactly are they?

A dermatome is an area of skin that receives sensory innervation from a single spinal nerve root. In simpler terms, it’s a patch of skin connected to a specific nerve emerging from the spine. These sensory nerves allow us to feel touch, temperature, and pain in different parts of our body.

A myotome, on the other hand, refers to a group of muscles innervated by a single spinal nerve root. These motor nerves control the movement and function of specific muscle groups.

Understanding dermatomes and myotomes is essential for healthcare professionals, as it helps them diagnose and treat various neurological conditions.

The Nervous System: Central and Peripheral

To better understand dermatomes and myotomes, it’s important to have a basic grasp of the nervous system’s structure. The nervous system is divided into two main parts:

• Central Nervous System (CNS): Consists of the brain and spinal cord
• Peripheral Nervous System (PNS): Comprises all the nerves outside the CNS

The peripheral nervous system includes 31 pairs of spinal nerves that branch out from the spinal cord. These nerves are responsible for transmitting sensory information from the body to the brain and motor commands from the brain to the muscles.

Spinal Nerve Anatomy and Distribution

Each spinal nerve emerges from the spinal cord through small openings between the vertebrae. These nerves are named and numbered according to their location along the spine:

• 8 cervical nerves (C1-C8)
• 12 thoracic nerves (T1-T12)
• 5 lumbar nerves (L1-L5)
• 5 sacral nerves (S1-S5)
• 1 coccygeal nerve

After exiting the spine, each nerve divides into smaller branches. The dorsal rami supply the skin and muscles of the back, while the ventral rami form complex networks called plexuses before innervating the rest of the body.

Major Nerve Plexuses and Their Functions

The ventral rami of spinal nerves form four major plexuses, each responsible for innervating specific regions of the body:

1. Cervical plexus (C1-C4): Innervates the diaphragm, shoulder, and neck
2. Brachial plexus (C5-T1): Supplies the upper limbs
3. Lumbar plexus (T12/L1-L4): Innervates the thigh
4. Sacral plexus (L4-S4): Supplies the leg and foot

These plexuses play a crucial role in distributing nerves to specific dermatomes and myotomes throughout the body.

Dermatome Patterns: Mapping Sensory Distribution

Dermatome patterns are remarkably consistent across individuals, making them valuable diagnostic tools. Each dermatome corresponds to a specific spinal nerve root and follows a predictable distribution on the body’s surface.

Key dermatome patterns include:

• C2-C4: Head and neck
• C5-T1: Upper limbs
• T2-T12: Trunk
• L1-L5: Lower abdomen and thighs
• S1-S5: Lower limbs and perineum

While there can be some slight variations between individuals, these patterns are generally reliable for clinical assessment.

Myotome Distribution and Function

Similar to dermatomes, myotomes follow a consistent pattern of distribution. Each myotome represents a group of muscles innervated by a specific spinal nerve root. Understanding myotome patterns is crucial for assessing motor function and diagnosing neuromuscular disorders.

Some key myotome functions include:

• C5: Shoulder abduction
• C6: Elbow flexion and wrist extension
• C7: Elbow extension and wrist flexion
• C8: Finger flexion
• L2: Hip flexion
• L3: Knee extension
• L4: Ankle dorsiflexion
• L5: Great toe extension
• S1: Ankle plantarflexion

Clinical Significance: Diagnosing Nerve Damage

Knowledge of dermatomes and myotomes is invaluable in clinical practice. How do healthcare professionals use this information to diagnose nerve damage?

When assessing potential nerve root damage, doctors perform tests on both dermatomes and myotomes:

Dermatome Testing

Dermatome testing involves assessing sensation in specific skin areas. Clinicians use various tools to test for abnormal sensations, including:

• Light touch (using cotton swabs or fingertips)
• Sharp/dull discrimination (using pinpricks or paperclips)
• Temperature sensation
• Vibration sense

Patients may experience different types of sensory abnormalities:

• Hypoesthesia: Decreased sensation
• Hyperesthesia: Increased sensitivity
• Anesthesia: Complete loss of sensation
• Paresthesia: Abnormal sensations like tingling or burning

Myotome Testing

Myotome testing involves assessing muscle strength and function. Clinicians typically use a grading scale to evaluate muscle weakness:

• 5: Normal strength
• 4: Active movement against gravity and resistance
• 3: Active movement against gravity only
• 2: Active movement with gravity eliminated
• 1: Visible or palpable muscle contraction, but no movement
• 0: No muscle contraction

By combining dermatome and myotome assessments, healthcare professionals can pinpoint the location and extent of nerve damage, guiding treatment decisions.

Common Conditions Affecting Dermatomes and Myotomes

Several medical conditions can affect dermatomes and myotomes, leading to sensory and motor disturbances. Some common conditions include:

• Herniated discs: Can compress nerve roots, causing pain and numbness in specific dermatomes
• Spinal stenosis: Narrowing of the spinal canal, potentially affecting multiple dermatomes and myotomes
• Radiculopathy: Irritation or compression of a nerve root, leading to pain, numbness, or weakness in the affected dermatome and myotome
• Peripheral neuropathy: Damage to peripheral nerves, often causing symmetrical sensory disturbances in dermatomes
• Shingles: Viral infection causing pain and rash along specific dermatomes

Understanding dermatome and myotome patterns helps clinicians differentiate between these conditions and develop appropriate treatment plans.

Advanced Diagnostic Techniques

While dermatome and myotome testing provides valuable information, advanced diagnostic techniques can offer more detailed insights into nerve function and damage. These techniques include:

Electromyography (EMG)

EMG measures the electrical activity of muscles, helping to assess the function of motor neurons and detect abnormalities in muscle activation. This test can provide detailed information about myotome function and identify specific nerve root involvement.

Nerve Conduction Studies

These studies measure the speed and strength of electrical signals traveling along nerves. By comparing results to normal values, clinicians can identify areas of nerve damage or compression affecting specific dermatomes.

Magnetic Resonance Imaging (MRI)

MRI scans provide detailed images of the spine and surrounding tissues, allowing clinicians to visualize nerve roots and identify potential sources of compression or irritation that may be affecting dermatomes and myotomes.

These advanced techniques, combined with thorough clinical examination and knowledge of dermatome and myotome patterns, enable healthcare professionals to make accurate diagnoses and develop targeted treatment plans for patients with neurological disorders.

Therapeutic Applications of Dermatome and Myotome Knowledge

Understanding dermatomes and myotomes not only aids in diagnosis but also plays a crucial role in developing effective treatment strategies. How do healthcare professionals apply this knowledge in therapeutic settings?

Targeted Pain Management

Knowledge of dermatome patterns allows for precise localization of pain sources, enabling targeted interventions such as:

• Epidural steroid injections
• Nerve blocks
• Radiofrequency ablation

These procedures can provide significant pain relief by addressing the specific nerve roots involved in a patient’s condition.

Rehabilitation and Physical Therapy

Understanding myotome distributions helps physical therapists and rehabilitation specialists design targeted exercise programs to strengthen specific muscle groups affected by nerve damage. This approach can improve functional outcomes and prevent further deterioration.

Surgical Planning

For patients requiring surgical intervention, knowledge of dermatomes and myotomes is essential for:

• Determining the exact location of nerve compression
• Planning the surgical approach
• Minimizing the risk of iatrogenic nerve damage
• Assessing post-operative recovery and function

By applying their understanding of these neuroanatomical concepts, surgeons can perform more precise and effective procedures with reduced risk of complications.

Emerging Research and Future Directions

As our understanding of the nervous system continues to evolve, researchers are exploring new avenues related to dermatomes and myotomes. What are some exciting areas of ongoing research?

Neuroplasticity and Dermatome Remapping

Recent studies have shown that the brain can reorganize sensory maps following injury or amputation. This neuroplasticity may lead to changes in dermatome patterns, presenting both challenges and opportunities for rehabilitation strategies.

Advanced Imaging Techniques

Researchers are developing new imaging modalities to visualize nerve pathways with unprecedented detail. These techniques may provide more accurate mapping of dermatomes and myotomes, potentially improving diagnostic accuracy and treatment planning.

Neuromodulation Therapies

Emerging neuromodulation techniques, such as spinal cord stimulation and transcutaneous electrical nerve stimulation (TENS), are being refined to target specific dermatomes more effectively. These therapies show promise in managing chronic pain and improving function in patients with neurological disorders.

Artificial Intelligence in Diagnosis

Machine learning algorithms are being developed to analyze patterns in dermatome and myotome testing results. These AI-powered tools may help clinicians make more accurate diagnoses and predict treatment outcomes with greater precision.

As research in these areas progresses, our understanding of dermatomes and myotomes will continue to deepen, potentially leading to more effective diagnostic and therapeutic approaches for patients with neurological conditions.

What Are Dermatomes and Myotomes?

The spinal cord and brain make up the central nervous system while the spinal nerves (branching to the spinal cord) and cranial nerves (branching to the brain) make up the peripheral nervous system. There are 31 sets of nerves that extend out of the spinal cord and are connected to it by the nerve root. Each nerve branches out about a half inch from the spinal cord before dividing into smaller branches. The dorsal rami are on the posterior side of the branch while the larger ventral rami are on the anterior side.

The dorsal rami provide nerve function for the skin of the trunk and posterior muscles. The ventral rami from T1 to T12 provide nerve function to the skin of the trunk as well as the lateral and anterior muscles. The anterior divisions that remain for plexuses, networks that provide nerve function to the body. Each plexus has specific areas on the body for skin sensitivity as well as certain muscles. Their point where they exit the spine determines how they are numbered. The four primary plexuses are:

• Cervical plexus, C1 – C4, innervates the diaphragm, shoulder and neck
• Brachial plexus, C5 – T1, innervates the upper limbs
• Lumbar plexus, T12/L1 – L4, innervates the thigh
• Sacral plexus, L4 – S4, innervates the leg and foot.

These spinal nerves have two sets of fibers: motor and sensory. Motor fibers facilitate movement and provide nerve function to the muscles. Sensory fibers facilitate sensitivities to touch, temperature and other stimuli. They provide nerve function to the skin.

What are Myotomes and Dermatomes?

A group of muscles that is innervated by the motor fibers that stem from a specific nerve root is called a myotome. An area of the skin that is innervated by the sensory fibers that stem from a specific nerve root is called a dermatome. These patterns of myotome and dermatome are almost always identical from person to person. There are occasionally variances, but that is rare.

This consistency allows doctors to treat nerve pain in patients. If a certain area is hurting, they know that it is attributed to a certain myotome or dermatome, whichever the case may be, and its corresponding nerve root. Problems with nerve damage is often the result of stretching the nerve or compressing it. When the nerves are injured in specific areas like the lumbosacral or brachial plexus, it presents as sensory and motor deficits in the limbs that correspond to them. Myotomes and dermatomes are used to assess the extent of damage.

How are Myotomes and Dermatomes used to Assess Nerve Damage?

When a doctor tests for nerve root damage in a patient, he or she will often test the myotomes or dermatomes for the nerves assigned to that location. A dermatome is tested for abnormal sensation, such as hypersensitivity or lack of sensitivity. This is done by using stimulus inducing tools such as a pen, paper clip, pinwheel, fingernails, cotton ball, or pads of the fingers. The patient is instructed to provide feedback regarding their response. Some of the abnormal sensation responses include:

• Hypoesthesia (decreased sensation).
• Hyperesthesia (excessive sensation).
• Anesthesia (loss of sensation).
• Paresthesia (numbness, tingling, burning sensation).

A myotome is tested for nerve damage in the muscles which presents as muscle weakness. This grading scale, which assigns a rating to the degree of muscle weakness, is often used:

• 5 – Normal – Complete range of motion against gravity with full resistance
• 4 – Good – Complete range of motion against gravity with some resistance
• 3 – Fair – Complete range of motion against gravity with no resistance, active ROM
• 2 – Poor – Complete range of motion with some assistance and gravity eliminated
• 1 – Trace – Evidence of slight muscular contraction, no joint motion evident
• 0 – Zero – No evidence of muscle contraction

During a typical chiropractic exam, your chiropractor will assess both dermatomes and myotomes for potential neurological problems. This gives him or her additional insight on how to treat your condition, whether it’s related to a subluxation of vertebral bodies or other other disease processes.

This article is copyrighted by Blogging Chiropractors for its Doctor of Chiropractic members and may not be copied or duplicated in any manner including printed or electronic media, regardless of whether for a fee or gratis without the prior written permission of Blogging Chiropractors.

12.6E: Dermatomes – Medicine LibreTexts

A dermatome is an area of skin that is supplied by a single spinal nerve, and a myotome is a group of muscles that a single spinal nerve root innervates.

Learning Objectives

• Describe dermatomes and how they relate to the peripheral nervous system

Key Points

• There are eight cervical nerves, twelve thoracic nerves, five lumbar nerves and five sacral nerves. Each of these nerves relays sensation, including pain, from a particular region of skin to the brain.
• Along the thorax and abdomen, the dermatomes are like a stack of discs, with each section supplied by a different spinal nerve. The pattern is different along the arms and the legs. The dermatomes run longitudinally along the limbs, so that each half of the limb has a different dermatome.
• Dermatomes have clinical significance, especially in the diagnosis of certain diseases. Symptoms that follow a dermatome, such as pain or a rash, may indicate a pathology that involves the related nerve root. Examples include dysfunction of the spine or a viral infection.

Key Terms

• shingles: Also known as herpes zoster, shingles is an acute viral inflammation of the sensory ganglia of spinal and cranial nerves associated with a vesicular eruption and neuralgic pains and caused by reactivation of the poxvirus causing chicken pox.
• chickenpox: A common childhood disease caused by the varicella-zoster virus.

A dermatome is an area of skin that is supplied by a single spinal nerve. There are eight cervical nerves, twelve thoracic nerves, five lumbar nerves and five sacral nerves. Each of these nerves relays sensation, including pain, from a particular region of the skin to the brain.

Dermatomes: Dermatomes are areas of skin supplied by sensory neurons that arise from a spinal nerve ganglion. Dermatomes and the associated major cutaneous nerves are shown here in a ventral view.

Along the thorax and abdomen, the dermatomes are like a stack of discs, with each section supplied by a different spinal nerve. Along the arms and the legs, the pattern is different. The dermatomes run longitudinally along the limbs, so that each half of the limb has a different dermatome.

Although the general pattern is similar in all people, the precise areas of innervation are as unique to an individual as fingerprints.

Dermatomes have clinical significance, especially in the diagnosis of certain diseases. Symptoms that follow a dermatome, such as pain or a rash, may indicate a pathology that involves the related nerve root. Examples include dysfunction of the spine or a viral infection.

Viruses that remain dormant in nerve ganglia, such as the varicella zoster virus that causes both chickenpox and shingles, often cause either pain, rash, or both in a pattern defined by a dermatome.

Shingles rash: The shingles rash appears across a dermatome. In this patient, one of the dermatomes in the arm is affected, restricting the rash to the length of the back of the arm.

Shingles is one of the only diseases that causes a rash in a dermatomal pattern, and as such, this is its defining symptom. The rash of shingles is almost always restricted to a specific dermatome, such as on the chest, leg, or arm caused by the residual varicella zoster virus infection of the nerve that supplies that area of skin. Shingles typically appears years or decades after recovery from chickenpox.

Mytome

A myotome is the group of muscles that a single spinal nerve root innervates. The myotome is the motor equivalent of a dermatome.

The myotome distributions of the upper and lower extremities are listed below:

• C1/C2: Neck flexion / extension
• C3: Neck lateral flexion
• C4: Shoulder elevation
• C5: Shoulder abduction
• C6: Elbow flexion/wrist extension
• C7: Elbow extension/wrist flexion
• C8: Finger flexion
• T1: Finger abduction
• L2: Hip flexion
• L3: Knee extension
• L4: Ankle dorsi-flexion
• L5: Great toe extension
• S1: Ankle plantar flexion/ankle eversion/hip extension
• S2: Knee flexion
• S3–S4: Anal reflex

The testing of myotomes provides the clinician with information about the level in the spine where a lesion may be present. During testing, the clinician looks for muscle weakness of a particular group of muscles. Results may indicate lesions to the spinal cord nerve root, or intervertebral disc herniation that presses on the spinal nerve roots.

Spinal Cord Injury Levels: What Functions Are Affected?

The level of a spinal cord injury refers to the lowest region of the spinal cord where normal motor control and sensation exist. Knowing one’s level of injury will help individuals determine what functions may be affected after an injury.

To help you understand what functions correspond to each of the spinal cord injury levels, this article will discuss:

What Your Level of Spinal Cord Injury Means

The spinal cord is the passageway that allows for communication between the brain and body. After a spinal cord injury, that connection is disrupted, and areas below the level of injury may no longer be able to effectively send or receive communication from the brain. Therefore, it’s essential to understand what your level of injury is to determine which functions may or may not be affected.

When determining your level of injury, a physician will test your sensory and motor functions using the International Standards for Neurological Classification of Spinal Cord Injury (ISNCSCI), also called the ASIA exam.

Each level of the spinal cord receives sensory information from a different area of skin called a dermatome. This information travels through the spinal cord to the brain for processing and to allow the brain to decide how to appropriately respond.

Additionally, each level of the spinal cord sends motor signals from the brain to different muscles throughout the body. The muscles designated to each level of the spinal cord are called myotomes.  

In the next section, you’ll learn more about how different levels of spinal cord injuries affect different dermatomes and myotomes. Before we get there, let’s discuss the anatomy of the spinal column.

The spinal cord is protected by the spine, which is composed of 33 vertebrae. Peripheral nerves (which connect the central nervous system to the rest of the body) branch out from the spinal cord in pairs and exit above or below their corresponding vertebrae (C1-C7 spinal nerves exit above the corresponding vertebrae, while the rest of the spinal nerves from C8 downward all exit below). For example, the C3 spinal nerves exit above the C3 vertebrae, while the T5 spinal nerves exit below the T5 vertebrae.

For each spinal cord level, there is a pair of spinal nerves (31 pairs in total), with one nerve going to the left side of the body and one going to the right. Furthermore, for each spinal nerve within the pair, there is a sensory nerve root that sends messages from the body to the brain, and a motor nerve root that sends messages from the brain to the corresponding area of the body. To give an example, at the C3 level of the spinal cord, there are nerve roots coming to (sensory) and from (motor) the spinal cord on both the right and left sides of the spine.

Additionally, the spinal cord is divided into 5 regions (from top to bottom):

• Cervical
• Thoracic
• Lumbar
• Sacral
• Coccygeal

The higher your level of injury, the more functions will be affected. This occurs because motor signals from the brain and sensory signals from the body cannot travel past damaged regions of the spinal cord. As a result, all motor functions and sensations innervated below the level of injury may be affected, depending on the severity of the injury (whether the spinal cord was completely severed or if some connections were left intact).

For example, a cervical spinal cord injury is not only going to affect functions innervated at the cervical region, but also functions associated with the thoracic, lumbar, and sacral levels.

However, all functions innervated above the site of injury will be normal and unaffected.

In the next section, we’ll go over what functions are affected at each level of injury.

Cervical Level of Spinal Cord Injury

The cervical region of the spinal cord consists of 8 pairs of cervical nerves in your neck area. Generally, a cervical-level spinal cord injury is the most debilitating because it has the potential to affect the entire body. Nearly 60% of all spinal cord injuries are cervical-level injuries.

Complete cervical spinal cord injuries result in quadriplegia, which describes paralysis in both the upper and lower limbs. The peripheral nerves that branch out of the cervical region of the spinal cord primarily innervate the neck, shoulders, arms and hands, providing both muscular control and sensation to these areas.

However, because all functions innervated below the level of injury can also be affected, individuals with cervical spinal cord injuries will frequently experience weakness or paralysis in the trunk and lower body as well.

Below, we’ll discuss which functions correspond to each specific level of the cervical spinal cord:

• C1 – The C1 segment of the spinal cord is unique in that it does not typically have a dermatome; however, because it is the uppermost segment of the spinal cord, most sensory and motor functions throughout the body may be affected.
• C2 – The C2 segment is connected to sensation at the back of the head, ears, and upper area of the neck. The muscles directly affected by C2 spinal cord injury affect your ability to nod your head up and down.
• C3 – The C3-C5 nerve roots innervate the diaphragm, which is essential for breathing. Injury to the C3 nerve roots will also affect sensation at the neck as well as the ability to tilt your head right and left.
• C4 – The C4 dermatome affects sensation at the shoulders, upper back, and upper chest. The C4 myotomes affect the ability to raise your shoulders.
• C5 – The C5 nerve roots affect sensation at the outer area of your upper arm and the ability to raise your arm up (shoulder abduction) and bend the elbows (elbow flexion).
• C6 – The C6 dermatome affects sensation at the outer forearms down to the thumbs and part of the index fingers. The C6 myotome affects wrist extension.
• C7 – The C7 nerve roots affect sensation at the middle finger. It affects the ability to straighten out your elbows and bend your wrists.
• C8 – The C8 nerve roots affect sensation at the ring and pinky fingers. The myotomes at the C8 level affect the ability to bend your fingers and grab objects.

Thoracic Levels of Spinal Cord Injury

Below the cervical region is the thoracic region of the spinal cord. This region of the spinal cord consists of 12 levels.

Thoracic-level spinal cord injuries primarily affect the muscles that make up your trunk and chest. As a result, individuals may experience difficulties with balance, posture, breathing, and coughing. The thoracic nerves primarily affect sensation of the chest and abdomen, with T3-T12 innervating progressively lower areas of the trunk.

Because the thoracic region is located below the cervical region, all functions innervated by the cervical region will be unaffected. Therefore, individuals with SCIs below the T1 level should be able to use their hands and arms normally.

The functions directly affected at each level of thoracic spinal cord injury include:

• T1 – The T1 dermatome affects sensation of the inner forearm. The T1 myotomes affect the ability to separate your fingers (finger abduction).
• T2 – T2 nerve roots affect sensation near the armpit and upper chest.
• T3 – T3 nerve roots affect sensation at the upper chest and back.
• T4 – T4 nerve roots affect sensation at the chest and back. It is generally aligned with the 4^th intercostal space (the space between the 4^th and 5^th ribs), level with the nipples.
• T5 – T5 nerve roots affect sensation at the chest and back between the T4 and T6 dermatomes.
• T6 – T6 nerve roots affect sensation between the T5^th and T7^th dermatomes. This is generally the area where the abdomen starts.
• T7 – T7 nerve roots affect sensation at the trunk between the T6 and T8 dermatomes.
• T8 – T8 nerve roots affect sensation at the trunk between the T7 and T9 dermatomes.
• T9 – T9 nerve roots affect sensation at the trunk between the T8 and T10 dermatomes.
• T10 – The T10 dermatome generally aligns with the belly button and will affect sensation at the lower trunk between the T9 and T11 dermatomes.
• T11 – T11 nerve roots affect sensation at the lower trunk between the T10 and T12 dermatomes.
• T12 – The T12 dermatome affects sensation at the very bottom of your abdomen.

Lumbar Levels of Spinal Cord Injury

Following the thoracic region is the lumbar region. This region of the spinal cord consists of 5 levels.

Lumbar spinal cord injuries only affect the lower body, so individuals should have unaffected motor control and sensation in their hands, arms, and trunk. Because individuals with lumbar spinal cord injuries experience weakness or paralysis in their legs, they may struggle with walking and balance.

The functions affected at each level of the lumbar spinal cord include:

• L1 – The L1 nerve roots affect sensation at the pelvic region.
• L2 – The L2 dermatome affect sensation at the upper thighs. The L2 myotomes affect the hip flexors, which are the muscles near the top of your thighs that allow you to raise your upper legs (such as during walking or marching).
• L3 – L3 nerve roots affect sensation at the lower thighs and knees. The L3 myotomes affect the ability to straighten the knees (knee extension).
• L4 – The L4 dermatome affects sensation at the front and inner regions of the lower legs. The L4 myotomes affect the ability to lift the foot upwards (ankle dorsiflexion).
• L5 – The L5 dermatomes affect sensation at the front and outer areas of the lower legs down to the big, second, and middle toes. The L5 myotomes affect the ability to bend and straighten the big toe.

Sacral Spinal Cord Injury

The sacral region of the spinal cord consists of 5 levels. Individuals with sacral-level spinal cord injuries have unaffected upper body functions and partial leg functions.

Because bowel and bladder functions are innervated by the bottommost segments of the sacral spinal cord, individuals with nearly any level of spinal cord injury are likely to experience bowel and bladder problems.

Functions linked to sacral levels of the spinal cord include:

• S1 – The S1 dermatome affects sensation at the fourth and pinky toes, heel, and part of the calf. An S1 spinal cord injury will affect the ability to extend the ankle so that the foot points down (ankle plantarflexion)
• S2 – The S2 dermatome affects the majority of sensation at the back of the legs. The S2 myotome affects the ability to bend the knees (knee flexion). The S2, S3, and S4 spinal nerves innervate the pelvic cavity, which is responsible for sexual, bladder, and bowel-related functions.
• S3 – The S3 dermatome affects sensation around the medial buttocks.
• S4 and S5 – The S4 and S5 spinal cord segments affect the perianal area.

Coccygeal Spinal Cord Injury

At the very end of the spinal cord is a single coccygeal nerve. This nerve innervates the skin around the tailbone. As a result, individuals may experience pain, discomfort, or complete loss of sensation in the tailbone area.

However, because this nerve makes up the lowest level of the spinal cord, individuals should have normal motor control and sensation throughout most of their bodies.

Spinal Cord Injury Levels and Functions: Key Points

Functional loss after spinal cord injury depends on the severity and level of injury. The severity of your SCI will determine to what extent functions innervated below your level of injury are affected. Likewise, the level of injury will determine which functions may or may not be affected.

We hope this article helped you better understand spinal cord injury levels and what sensorimotor functions they affect.

Photo credits: ©iStock.com/sankalpmaya/Ralf Stefan/PALMIHELP/peterschreiber. media

Dermatomes | DermNet NZ

Authors: Claire Jordan Wiggins, Riyad N.H. Seervai, Medical Students, Baylor College of Medicine, Houston, TX, USA. DermNet NZ Editor in Chief: Adjunct A/Prof Amanda Oakley, Dermatologist, Hamilton, New Zealand. Copy edited by Gus Mitchell. June 2020.

What is a dermatome?

A dermatome is an area of skin that is primarily supplied by a single nerve root: communicating sensation from this skin region to the brain. Somatosensation includes feedback from mechanoreceptors, thermoreceptors, proprioceptors, pain receptors, and chemoreceptors. Dermatomes are different from Blaschko lines.

Maps of dermatomes are not consistent, and variation will be noted between different sources.

Dermatomes

Credit: https://www.grepmed.com/images/2963/dermatomal-dermatomes-diagnosis-cutaneous-anatomy-nerves-roots

Where are dermatomes located?

Dermatomes form a stack of horizontal layers on the trunk and run lengthwise in the extremities.

• There are eight cervical nerves (although C1 does not have its own dermatome), 12 thoracic nerves, 5 lumbar nerves, and 5 sacral nerves.
• The 5th cranial nerve is divided into three divisions; V1, V2, and V3, which are responsible for sensation in the face.
• Contiguous dermatomes overlap, and each individual’s exact dermatomal pattern is unique.

What is the clinical relevance of dermatomes?

Knowledge of dermatomes can aid in the diagnosis of disease.

• Herpes zoster (shingles), a viral infection caused by varicella-zoster virus. The virus can lie dormant in the spinal nerve ganglia, producing a rash and pain along the corresponding dermatome.
• Lumbar radiculopathy, a radiating back pain extending down a dermatome is due to compression of a spinal nerve root (sciatica).
• Referred pain from a visceral organ can be perceived at a location other than the site of the stimulus or origin in a nearby dermatome.

Sensory Exam

Definition (MSH)	Sensation of making physical contact with objects, animate or inanimate. Tactile stimuli are detected by MECHANORECEPTORS in the skin and mucous membranes.
Definition (GO)	The series of events required for an organism to receive a touch stimulus, convert it to a molecular signal, and recognize and characterize the signal. This is a neurological process. The perception of touch in animals is mediated by mechanoreceptors in the skin and mucous membranes and is the sense by which contact with objects gives evidence as to certain of their qualities. Different types of touch can be perceived (for example, light, coarse, pressure and tickling) and the stimulus may be external or internal (e.g. the feeling of a full stomach). [GOC:ai]
Definition (NCI)	The faculty of touch, the sensation produced by pressure receptors in the skin.
Definition (PSY)	Awareness of the qualities or characteristics of objects, substances, or surfaces by means of touch.
Definition (CSP)	group of senses by which contact with objects gives evidence as to certain of their qualities, as registered by mechanoreceptors in the skin and mucous membranes.
Concepts	Organ or Tissue Function (T042)
MSH	D014110
SnomedCT	70761002, 397624008
LNC	LP30265-0, MTHU001444
English	Touch, Touch sensation, touch, tactile sense, taction, tactition, perception of touch, sensory perception of touch, tactual discrimination, tactual perception, Sense, Tactile, Senses, Tactile, Taction, Tactile Senses, Tactile Sense, Sense of Touch, Touch Sense, Tactions, Touch Senses, sense of touch, tactile sensation, touch sense, sensation touch, senses touch, sensation touching, touch sensation, sensation tactile, sense touch, Tactile sensation, Tactile sense, Sense of touch, Touch sensation, function (observable entity), Touch sensation, function, Touch sensation (function), Tactual Discrimination, Tactual Perception
Swedish	Beröring
Czech	hmat
Finnish	Kosketus
Russian	OSIAZANIE, ОСЯЗАНИЕ
Japanese	触覚, タッチ
Spanish	Senso Táctil, sensación táctil, tacto (entidad observable), tocar, sentido táctil, tacto, sensación de tacto, función (entidad observable), sensación de tacto, función, tacto (función), Tacto
Portuguese	Senso Tátil, Sentido do Tato, Tato
Polish	Zmysł dotyku, Dotyk
Norwegian	Berøring
French	Toucher
German	Berührung
Italian	Tatto
Dutch	Tast

Sensory Nerves and Deep Tendon Reflexes

Sensory
Numbness, tingling, burning, and pain are abnormal feelings that may be felt in the back and/or extremities. Sometimes these symptoms radiate from one area into another. Sciatica is a good example of pain that can radiate into an extremity (leg).
Sciatica is a good example of pain that can radiate into an extremity (leg).Nerves originate from the spinal cord and divide into sensory and motor nerves. The sensory nerve gives sensation to the skin (dermatomes). The dermatomal patterns appear similar to a map on the body. For example, dermatomes on the trunk of the body correspond to the thoracic spinal nerve roots, those on the arms to the cervical spine nerve roots, and legs to the lumbar spinal nerve roots.

The physician may use a piece of cotton, a swab, pin or paperclip to test symmetrical feeling in the arms and legs. Abnormal responses may be indicative of a nerve root problem.

Deep Tendon Reflexes
Most people have experienced their physician tapping their knees with a rubber hammer. The normal response is a ‘knee jerk’. This is an example of a reflex, which is an involuntary muscular response elicited by the rubber hammer tapping the associated tendon.

When reflex responses are absent this could be a clue that the spinal cord, nerve root, peripheral nerve, or muscle has been damaged. When reflex response is abnormal, it may be due to the disruption of the sensory (feeling) or motor (movement) nerves or both. To determine where the neural problem may be, the physician tests reflexes in different parts of the body. See the following examples in the chart below.

Dermatome Patterns – ShimSpine

Dermatome Patterns

Posted on June 26, 2013 | by Dr. Shim

Dermatomal Patterns help physicians define nerve radiculopathy patterns.  Most neurologists/spine specialists  accept certain associated sensation, muscle strength, and reflex changes patterns to specific nerve roots.

L5 radiculopathy is typically associated with weakness of the extensor hallucis longus muscle.  That is the muscle that allows the great toe to point upwards.  L5 radiculopathy also follows a dermatomal pattern associated with the front of the foot.  There are no reflexes associated with L5.

SI radiculopathy is associated with weakness of the gastrocnemius muscle.  That is the muscle that allows a person to step on their tip toes.  S1 radiculopathy follows a dermatomal pattern  associated with the outer heel, and back of the calf.

But, as physicians,  we know that there can be considerable overlap in the sensation changes associated with each of these dermatomes.

In the above study published in  SPINE,  the authors mapped out the distribution of pain and pins and needles patterns in patients with known disk herniations causing specific entrapment of either the L5, or the S1 nerve.

After mapping the sensation patterns of these patients,  the authors came to the conclusion that patient report is an unreliable method of identifying the anatomic source of pain or paresthesia by nerve root compression.

The results read “There is a substantial overlap of the dermatomes with most patients indicating pain or pins or needles in more than the dermatomal area.  In addition, the distribution of pain and pins and needles did not correspond well with dermatomal patterns.”

Clinicians know this statement to be true.  As I explain to patients,  “I guess your S1 nerve did not read the anatomy book”,  as the pattern was not consistent.

In my opinion,  dermatomal patterns are helpful to establish  the presence of a radiculopathy.  But, as the author concludes,  these dermatome patterns do not always exactly follow the pattern.  But,  while I appreciate the fact that there is deviations of the dermatome patterns,  what I do look for is a pattern.  For patients that have global pain to one extremity,  it is likely that that global loss of sensation,  or  pain, is secondary to non-dermatomal issues such as neuropathy,  cord compression,  or non-physical matters.

Last modified: January 5, 2018

Kuznetsov_S_L__Mushkambarov_N_N_ – Page 12

Thus, at a certain stage of differentiation, pluripotent HSCs (hematopoietic stem cells) turn into at least eight types of unipotent cells, each of which can develop into only one type of blood cells.

b) The mechanism of committing is persistent repression of some genes and derepression of other genes.

Thus, as cells develop, the spectrum of functionally active genes gradually changes, and this determines an ever narrower and more specific direction of further development of cells.

2. Determination

a) At a certain stage, committing leads to the fact that the cell has only one path of development: such a cell is called deterministic.

In other words, determination is by

a phenomenon in a cell of genetic programming only for one path of development.

b) It follows that determination is a narrower concept than committing: the transformation of totipotent cells into pluripotent, oligopotent, and, finally, unipotent is all committing; one can speak of determinism only in relation to unipotent cells and all subsequent cells.

Indeed, the poly or oligopotent cell is not yet determined: it retains different variants of development.

7.1.2.3. Differentiation and Differeon

1. Differentiation. The implementation of the program for the development of a determined cell changes over time the morphology and functions of the cell (or its descendants). Such events are designated as differentiation (clause 2.1.1.2).

In other words, differentiation is

sequential change in the structure and function of the cell, which is due to the genetic program of development and leads to the formation of highly specialized cells.

Thus, differentiation is a more general concept than committing and determination: it includes both those initial events at the genetic level that constitute the essence of committing and determination, and subsequent changes in the biochemistry and morphology of cells.

2.Differon. The concept of differentiation is closely related to differentiation. According to

Section 4. General Histology

p. 5.2.1.2, a diferon is a set of cellular forms (from stem cells to highly differentiated ones) that make up op-

A definite line of differentiation.

Cells of several different differons can be present in the tissue. Moreover, as noted earlier (clauses 5.2.1.2 and 7.1.1.2), in an adult, some differons are represented by all their cells, while others are represented only by specialized cells (without previous cell forms).

7.1.3. Providing homeostasis

7.1.3.1. Stationary state of trims

1. Definition. In those cases when the differentiation process constantly takes place in the diferon (as, for example, in the epidermis), a steady state (or a state of dynamic equilibrium) is normally established: each cellular form of the diferon is formed at the same rate as it decreases (as a result transition to subsequent forms, withering away or deletion).

In this case, the content of each type of cells of the diferon turns out to be constant.

2. Condition of stationarity

a) To maintain a steady state of a constantly renewing diferon, it is necessary that its cambial cells (stem or semi-stem) not only regularly enter into differentiation, but also regularly replenish their stock.

b) This can happen in two ways.

I. In one case, each division of cambial cells is asymmetric, i.e.i.e. leads to the formation of two different cells, of which one is identical to the parent,

the author enters into differentiation.

II. In another case, all divisions are symmetrical, but there are two types:

– undifferentiated (both daughter cells remain cambial)

– and differentiating (give two cells entering maturation).

Moreover, divisions of the first type should be at least 50% of all divisions of cambial cells.

c) One way or another, in order for the update of the diferon to take place in a stationary mode, cambial cells must have the ability to self-support.

Otherwise, the production of mature cells of a given differon gradually dies out.

Laser therapy

History. The use of artificial light sources in physiotherapy – electric lamps with light filters (to select the desired spectrum), whose parameters (power, time, area and localization of exposure) could be controlled, has been known since the end of the 19th century. For the development of a new method of treatment – phototherapy for a number of diseases, the Danish physiotherapist N.R. Finsen was awarded the Nobel Prize in Medicine in 1903. The author of the technique and his followers were convinced that the effectiveness of phototherapy or chromotherapy, as they said then, is directly related to the width of the spectral band, the smaller it is, the higher the therapeutic effect.

It is not surprising that with the advent of lasers with a spectral line of the minimum width, in fact, one wavelength, the technique reached a fundamentally new level, and became known as laser therapy . In addition, laser diodes (diode lasers), which are currently used in all modern laser therapeutic devices, make it possible to better control the parameters of the technique and vary them over a wider range.

Lasers have revolutionized many fields of science and technology, including medicine. As for laser therapy, in the historical aspect, an evolutionary triad can be traced: heliotherapy – phototherapy – laser therapy [Moskvin S.V., 1997].

The impetus for the advancement of one of the most promising areas of modern physiotherapy was the official recognition of the method in Europe in 2000 and in the USA in 2003, which led to a real boom in its distribution throughout the world.

Advantages of the method. For effective treatment, it is necessary to strictly and consistently set all parameters of the laser therapy technique: wavelength, operating mode and power of LLLT, exposure time, type of technique, pulse repetition rate, localization of exposure and frequency [Moskvin S. IN 2014]. The absence of one of them in the description of the technique or the choice of a mode outside the effective values ​​can lead to the opposite of the expected result. The methodology and technology of laser therapy procedures are extremely simple, but it is necessary to understand the peculiarities of the method application, in specialized courses it takes several hours, in addition, a lot of special literature is available.

One of the advantages of laser therapy is the absence of absolute contraindications, but there are relative, known and understandable to specialists [Laser therapy…, 2015].

Laser therapy is included in the standard of medical care for patients in most areas of medicine. Oncology, pregnancy, tuberculosis, the patient’s age, etc. is not a contraindication, it is only about choosing the right technique. Appropriate specialists (oncologists, phthisiatricians, obstetricians-gynecologists, pediatricians, etc.) should prescribe and carry out treatment, of course, together with physiotherapists.

Security. Thousands of studies conducted in dozens of countries around the world for decades, studying the antitumor effect of low-intensity laser light, not only showed its complete safety, but more and more clinical studies appear, proving the prospects and safety of the use of laser therapy in the complex treatment and rehabilitation of cancer patients [Moskvin S.V., Strazhev S.V., 2020].

Mechanisms of LLLT therapeutic action. An important stage in the development of the methodology of laser therapy was the proof of the fact that the primary mechanism of the biological (therapeutic) action of LILI is based on the thermodynamic triggering of Ca ²⁺ -dependent processes at the cellular and organismal levels [S.V. Moskvin, 2008, 2010 ]. As a result, scientists and medical practitioners were able not only to explain a wide range of phenomena occurring as a result of laser illumination, to show and substantiate the limits of safe application of the method, but also learned to predict a change in the direction of the body’s response to exposure due to the correction of the parameters of the technique. The most important recommendations for clinical practice appeared, it became clear what and how should be changed in the technique (wavelength, power or mode of laser operation, or localization of exposure, or exposure or frequency) in order to increase the effectiveness of treatment [Moskvin S.V., 2014] …

Indications for laser therapy are extremely diverse due to the non-specificity of the method due to the mechanisms underlying the biological (therapeutic) effect of low-power laser light. As a result of illumination of LILI, a short-term increase in the concentration of free calcium (Ca ²⁺ ) in cells is initiated, with the further development of a cascade of body responses to external influences: the functioning of the immune and vascular systems is normalized, metabolic and proliferative processes are activated, an analgesic effect, etc. …(see fig.) [Moskvin S.V., 2008].

The sequence of development of biological effects after exposure to LILI (mechanisms of biological and therapeutic effects of LILI)

Basic methods of laser therapy. Russia is a world leader in both scientific substantiation and practical application of laser therapy. According to various estimates, from 150 to 200 thousand laser therapeutic devices operate in health care institutions, and many more have been purchased by the population.For several decades, thousands of dissertations have been defended in Russia on the study of the biological and therapeutic effects of low-intensity laser light, as well as the clinical application of laser therapy. The result of the research was the substantiation of the parameters of numerous methods of laser therapy, the main of which are presented in the table.

⁽¹⁾ – average power for continuous mode
⁽²⁾ – pulsed power for pulsed mode
⁽³⁾ – for pulsed mode
⁽⁴⁾ – more efficient matrix laser emitters

One of the most widespread methods of laser therapy is intravenous laser blood illumination (ILBI), the reason for this is its versatility and high efficiency.At present, in addition to the “classical” ILBI version, when red laser light (635 nm) is used, the technique of ultraviolet laser illumination of blood (LUFOK ^® ) is more and more widely used – the wavelength is 365-405 nm, and ILBI-525 in the green area spectrum – wavelength 525 nm.

The goal and task of the project is the development of laser therapy as a highly effective method of treatment, analysis of scientific information, which is contradictory. The team of authors will be glad to receive comments or questions by e-mail: 7652612 @ mail.ru. The answer is guaranteed, discussions are welcome, we will be grateful for providing information for posting on the site.

Acupuncture article on medicine – Docsity

Acupuncture PLAN: 1. History of acupuncture 2 2. The system of Chinese classical zhen-chiu therapy 6 3. Mechanisms of acupuncture 16 List of recommended literature 27 1. History of acupuncture Where, when and how methods of reflexology appeared acupuncture (acupuncture, acupuncture, acupuncture – from lat.acus – needle, punctio – stabbing) and moxibustion – has not yet been precisely established. Apparently, their origins can be attributed to the most ancient methods of healing. In an effort to relieve himself of pain or reduce it, the person instinctively rubbed bruised or other painful places. At the same time, painful points (points) on which the person acted were identified. This was probably the very first period of reflexology, when the impact was made only on painful points. The extraction of fire by primitive man may have served as an impetus for the development of the method of cauterization.To survive in those conditions, primitive people had to be healthy and strong. This is probably why they, believing in the powerful power of fire, began to cauterize wounds, bites or painful places in order to recover faster. (Similar methods of treatment for wounds, bleeding, ulcers are currently used by some peoples.) However, strong moxibustion, as well as massaging painful points, was accompanied by pain, and, knowing that pain at the moment of moxibustion contributes to a further decrease in pain from wounds or bruises, people seem to have found another, almost similar, way to reduce suffering.They inflicted painful irritation with any object that came to their hand (stone, stick, etc.), just to reduce their suffering. This is evidenced by the historical and archaeological finds of stone (silicon, jasper, quartz), bone and bamboo needles of various shapes and sizes. Prolonged use of moxibustion (in ancient times, lumps of smoldering wormwood were used) and acupuncture made it possible to identify certain patterns when exposed to a particular point. The impact on some points was effective in one disease, on others – in another.The points received their names and topographic descriptions. When a significant amount of factual material was accumulated, it was found that exposure to different points can equally affect the same organ. At the same time, the “points of the same direction” began to be grouped along certain lines, which later received the name of channels. This was the period of systematization of points. China is considered to be the birthplace of the method of acupuncture, but it was not the “exclusive property” of the Chinese. There are reliable facts showing that in ancient times acupuncture also existed among other peoples.For example, in one of the museums in London, there is an Egyptian papyrus with the designation of points for acupuncture, dated 1550 BC. Perhaps acupuncture and moxibustion appeared earlier in Tibet, Nepal or India, where science was more advanced. It should nevertheless be noted that acupuncture and moxibustion were most widespread in the countries of the East, primarily in China, and therefore this method of treatment was called the Chinese method of treatment or zhen-chiu therapy. The doctors of China, through trial and error, passed on the accumulated experience from generation to generation, multiplying and developing it.One of the first written documents on acupuncture that has come down to us was the book Huangdi nei-ching (Treatise on the Inner, or On the Nature of Life), written in China around 221 BC. It reflects the issues of acupuncture and moxibustion, describes nine forms of metal needles, topography of 295 points (135 paired and 25 unpaired), outlines the main indications and contraindications, as well as the rules of acupuncture, based on more than 2000 years of experience in the use of acupuncture and moxibustion. Follows the “Instructions for the use of the method of acupuncture”. Clinical and physiological study of the method was carried out under the guidance of professors N.I. Grashchenkov, E.D. Tykochinskaya, V.G. Vogralik and I.I. At the departments of physiotherapy and neurology, the training of relevant specialists began. In 1960, at TSOLIUV, a course of acupuncture was organized for the first time. At the same time, acupuncture courses functioned in Kazan, Gorky and Leningrad. Then there was a decade-long decline in the use of the acupuncture method. After the order of the USSR Ministry of Health “On the further development of the method of acupuncture and its introduction into practice” (1971), the training of doctors in acupuncture was again intensified.It was established in 1978, and in 1985 and 1991. the unified reflexology program for advanced training institutes for doctors has been revised taking into account the accumulated experience. The program provides for general training of specialists of different profiles in reflexology, designed for a three-month training period. In parallel, it is envisaged to conduct thematic improvement cycles for persons who have undergone general training in reflexology. 2. The system of Chinese classical zhen-chiu therapy At present, the interest in alternative medical systems and health-improving practices is extremely high.A special place among them is occupied by the phenomenon of traditional Chinese medicine, many of the methods and theoretical postulates of which are already widely used in world clinical practice. The time of the emergence of the zhen-chiu method (acupuncture and moxibustion) has not been precisely established, although archaeological data indicate that this type of treatment was used in the territory of modern China as early as the Stone Age [Gavaa Luvsan, 1986]. The Yellow Emperor’s treatise on the inner [Huang Di nei-ching, presumably III c.BC], the earliest of the purely medical books that have come down to us, is the canon of Chinese medicine and, in addition to the basic theoretical provisions of Zhen-chiu, contains the first systematized information about the essence of biologically active points and the meridians that unite them. The semi-legendary emperor Huang Di says: “I heard that in times of high antiquity, the perfect wise had a theory explaining the structure of the human body. They distinguished the organs Zhang (dense) and fu (hollow), distinguished the channels of jing (meridians) and lo (branches), they understood the jing points of the jing, knew the sequence of qi circulation (breathing) along the meridians, knew at which points the qi passes and in what sequence, and each place had its own designation.The beginning was determined for each meridian. The direct and reverse sequence of movement / qi / for each area was known, and in all cases they knew the clear patterns of the development of events, knew their correspondence to the substances of yin and yang, since there were laws of correspondence between internal and external, and for any phenomenon there was biao (superficial) and whether (deep) levels of consideration. Of course, the judgments of the author or authors of the ancient treatise are deeply metaphysical and correspond to the ontological and cultural views of their time. Thus, Heavenly Teacher Qi Bo, answering the Yellow Emperor’s question about the nature of the spirit (shen), explains: “In a state of clear concentration, you can see its essence, but words cannot convey it.” Blood (xue) and energy substance (qi) of a person make up his spirit (shen). “There are water channels on the earth, but in the human body there are meridians” through which xue and qi circulate incessantly. “If the location is correctly determined, then needles or stones can be used to act on points accordingly” in the treatment of diseases.With the help of acupuncture, excess blood (xue) and breath (qi) can be released from the meridian (jing), as a result of which the cause of the disease disappears. Thus, despite the clear substantial differentiation of the concepts of xue and qi (blood is both a product and a receptacle of qi), the ancient authors did not draw a clear morphological boundary between blood vessels and energy meridians, however, a priori, considering them not at all identical (blood fills all meridians and blood vessels, but qi breathing, circulating in different concentrations along all meridians, does not fill any of the blood vessels in its pure form). The presence in the human body of a system of jinglo channels (meridians and branches), which are “streams”, along with the existence of the heart and blood, was considered a manifestation of the element of fire, however, with the proviso that heat and the bitterness generated by it destroy qi in the same way as generated by heat joy destroys the heart. Such a classification according to five elements (fire, earth, metal, water, wood), symbolizing the five energy states of matter, is applicable to the definition of the interaction of forces in any possible situation, system, structure and is an integral part of the general concept of systematization in situational analysis of traditional Chinese ontology. polarized by the concepts of yin and yang.The main principle of the therapeutic effect on biologically active points and meridians is precisely the restoration of a dynamically harmonious balance between these substances. The channels of the twelve meridians (jing) known in ancient times and the corresponding fifteen branches (lo), along which the qi of the internal organs moves on the surface of the body, are also subdivided into yin and yang, depending on their topography and polarity. The qi circulation through the jing-lo system is constantly regulated by special shu (points), and thus the balance between the yin and yang substances is maintained.In the section “Su-wen” of the treatise “Huang Di Nei-Ching” it is said: “Yin is connected with yang, and their connection occurs at special points. The substance of yang is poured into the substance of yin, and the substance of yin fills the outer spaces. Yin and yang are thus they are distributed evenly, fill the bodily form. This state is called even (health). ” This is how the idea of ​​a biologically active point was formed as a specific area, like an opening in the body, through which the chang-fu organs exchange energy with the space surrounding the organism.The Huang Di Nei Ching treatise had a fundamental influence on the subsequent development of Chinese medicine, since it served as the source of all further research, and the overwhelming majority of classical texts are compilations of the Nei Ching postulates with the author’s comments [Y. Manaka, 1972]. So more than half of the chapters of the second most important treatise in the system of canonical compositions of Chinese medicine, the treatise “Difficult Questions” [Nan-jing, presumably II century. BC BC] are devoted to the explanation and development of the concepts of “Nei Ching”.In these canons, the structural and morphological characteristics of biologically active points are extremely poetic, but their figurative descriptions, which are probably exhaustive for the Eastern consciousness, cannot be recognized as such by modern Western researchers. For example, on each of the twelve main meridians, there are five points located below the elbows and knees, united by the collective term wu-shu (five points of shu). Their morphological and functional characteristics boil down to the statement that “where qi appears in the body, the point is a well-jing; where qi oozes, a stream-jong point arises; where qi flows, a point is a rivulet-shu; where qi moves like a stream, the river-jing point is formed, and where qi enters the body, moving to the chang-fu organs, the more-he point is formed. “All points (shu) are subdivided according to primary elements, and the treatise “Nan-jing”, without refuting this orthodox statement, however, puts forward its original judgment that the points-wells of organs and zhang and fu correspond to the primary element Wood. This important theoretical proposition once again emphasizes the paramount importance of the dense organs of the Zhang in the physiology of the organism. The same idea is reinforced by dividing the shu region in depth into three zones: the upper (skin and subcutaneous tissue) corresponds to the heart and lungs, the middle (muscles) corresponds to the spleen, and the lower (ligaments and bones) corresponds to the liver and kidneys.In each case, depending on the season and the phase of the moon during Zhen, the needle should be inserted to a strictly defined depth. These prescriptions allow us to conclude that the ancient physicians did not assume their own unique structure at biologically active points, but considered them to be formations consisting at different levels of morphologically heterogeneous elements, which in certain situations unite into a qualitatively new whole – the Shu point, capable of exhibiting unique properties, such as density and soreness on palpation, different from the surrounding tissues, and the occurrence of specific, later called “intended” sensations (thi) during pricking and pressure. according to the already mentioned S. de Morant [1955], some meridians correspond to the course of the nerves, others – to the vessels, which is consistent with the hypothesis of F. Hubotter [1929], who considered the channels of the yang system as nerve trunks, and the yin systems as the neurovascular plexus. T.Ischikawa [1962] also regards EM as real anatomical formations, noting “the amazing proximity of the course of the meridians of the topography of the nerve trunks and neurovascular formations”. VG Vogralik [1961], summarizing similar data, summarizes: “the meridian is the nerve conductors that go in the integument of the body, intertwining the lymphatic and blood vessels, muscles, then passing into the nerve plexuses, spinal cord and brain, and then into the nerves going to the organs “.G. Kellner [1966] investigated the structure of the skin and underlying tissues in the area of ​​the 24 most frequently used BAPs, in the places of EM passage and in neutral zones, making 250-300 preparations from each study area in the form of layer-by-layer sections. He found that in the area of ​​points and meridians there are certain histological differences from the control sites, consisting in the accumulation of heterogeneous receptors (Meissner’s bodies, Krause cones, glomuses) and smooth muscle fibers. J. Bossy [1975], who studied the morphology of many BAPs in detail, cites data according to which the saphenous nerve was found in 42% of cases in the area of ​​the point, in 40% – the saphenous vein with perivascular nerve plexuses, in 18% – the saphenous artery with perivascular plexuses.Research laboratory FG Portnov [1980] shows that these elements – saphenous nerves, arteries, veins – are present in the BAP region in about 80% of cases. Of particular interest in this regard is the bifurcation theory of V.A. Ionichevsky [1984], who, as a result of a detailed topographic analysis, showed the connection between the localization of the overwhelming majority of BAPs with the sites of branching of blood vessels and nerves, that is, with those areas where blood flow (and possibly energy), according to the researcher, from laminar to turbulent. It is known that this process is characterized by certain energy losses, possibly determining the functional features of these areas. The meaning of Zhen-Chiu therapy in the light of the bifurcation theory is to remove “stagnation” and “blockade” in the circulation of energy throughout the body. A.N. Shabanov et al. [1998], while investigating the innervation of auricular points, found that nerve fibers that give a positive reaction to acetylcholine pass in the dermis as a part of compact and non-compact nerve trunks and bundles, the number of which per one cut is much greater in BAP (approximately in 1 , 5 – 3 times) than in the dermis of the control skin areas.According to the structural organization of nerve elements and the type of their localization, active points are indistinguishable from neighboring areas, however, the authors propose to consider the constant presence of free nerve endings in the epidermis as a feature of BAP. P. Rabischong et al. [1975] showed that in the BAP area the epidermal layer is thinner, and the collagen fibers of the dermis are distinguishable from those located in the adjacent areas; they also found spiral vascular plexuses surrounded by myelin-free nerve fibers of the cholinergic type. H. Goux [1955] expressed an opinion about the similarity of the functioning of the yin-yang system of meridians and the autonomic nervous system with its adrenergic and cholinergic mechanisms. W.Lang [1957] also classifies yang meridians as afferent, and yin meridians as efferent pathways of the sympathetic nervous system. F.Mann [1973] comes to the conclusion that if we assume that the flow of “vital energy of the meridian is a wave of electrical depolarization going through the fibers of the ANS, then the meridian can be considered as a fiber of the autonomic nervous system.”In addition, V.G. Adamenko [1969] discovered a change in the diameter of active points depending on the state of a person – during sleep and after a pronounced creative load, the diameter of the BAP can be less than 1 mm, upon awakening it often increases to 10 mm, and in the state emotional stress and in acute diseases, the area of ​​individual points increases so much that they can merge, forming whole areas with increased conductivity. The data of J. E. H. Niboyet [1963], who for the first time determined the area of ​​BAP equal to about 1 mm2, about its electrical properties laid the foundation for a new direction in the study of the problem, and the studies carried out jointly with A.Mery [1958] made it possible to conclude that energy meridians objectively exist and pass mainly in the subcutaneous tissue, which is confirmed by the presence of specific electrical characteristics of the skin in places corresponding to the course of EM, in the form of a decrease in electrical resistance. It was found that this phenomenon persists even on a corpse – until the integrity of the skin is broken. The described features turned out to be even more pronounced after death: the difference in electrical resistance between the BAP and the surrounding skin of a dead person is greater than that of a living person.The safety of points and meridians was also established not only on the whole corpse, but also after its dismemberment. These facts were confirmed in the works of a number of authors from different countries [V. G. Vogralik, G. M. Pokalev, 1961; T. Ischikava, 1962; J. F. Dumitrescu, 1967; J. Borsarello 1969; G. Cantoni, 1970; W. Melhardt, 1975 and others]. G. Grall [1968] found that after transplantation of a skin flap, the topography of biologically active points and meridians remains unchanged in the areas under consideration. The transplanted flap loses its original properties immediately after its separation from the donor region and over time acquires new electrical characteristics that are already characteristic of the recipient region, from which the author concludes that “the skin is only a support and reflection of the circulation of deeper energy, the currents of which unchanged. “In addition, according to the data of A. K. Podshibyakin [1952, 1960] in the area of ​​BAP, the processes of oxygen absorption and release of carbon dioxide are enhanced, and the skin temperature is increased. GD Novinsky [1959], conducting research under the guidance of DA Zhdanov according to the method of VP Vorobiev, showed that the BAP area is characterized by the presence of looser connective tissue, which, according to the researcher, affects the physiological characteristics and allows using physical devices to determine their localization. N.V. Mikhailov [1985], considering the body as a system in which there is a constant exchange of various types of energy, rightly notes that this exchange is ordered not only within the nervous system, but also in other tissues, especially highlighting the connective tissue in this regard, since it, being ubiquitous in the body in the form of fibrous and reticular structures extended over long distances, and, being built from proteins with semiconducting properties, is capable of conducting energy flows “as through channels”.According to the hypothesis of N.V. Mikhailov, the appearance of the nervous system in evolved organisms did not lead to the loss of the ancient functions of connective tissue structures as energy conductors, and these structures, combined with nerve formations, form a completely special type of reflex connections in the mammalian body. A sensational report was made in 1964 by the Korean biologist Kim Bong Han, who discovered, as he believed, the hitherto unknown anatomical-histological “kenrak system”, distinct from the nervous, circulatory and lymphatic systems. In his opinion, this system consists of “Bon Khan bodies” located in the area of ​​biologically active points and connected by tubes in which a viscous liquid circulates, containing up to 2000 mg% DNA and 330 mg% RNA. Superficial Bonchan bodies consist of an outer layer formed by smooth muscle fibers and an inner substance, which is a special chromaffin cells and a network of numerous blood vessels; deep Bonchan bodies do not have an external muscle layer, but consist of polymorphic cells and basophilic substances.Each Bonchan tube connecting the Bonchan bodies is formed by bundles of Bonchan tubes, which have a special striated structure, and their walls are composed of very thin endothelial cells. Bonchan bodies and tubes, according to the author’s assurances, have the ability to conduct electrical impulses. However, this message has not yet been confirmed by other researchers either in Korea itself or in other countries, and, judging by the literature data, the morphological study of the Bonhan “kenrak system” is currently not being carried out. Is that the Japanese author Fujita [according to V.G. Vogralik, M.V. designed for the movement of fluids in tissues (along interstitial gaps, lymphatic pathways). Although he does not insist on the presence of a special system of thin-walled channels corresponding to the meridians, he nevertheless connects them with the system of interstitial gaps and ducts for intercellular fluid.The recently revealed ability of the meridians to ensure the movement of radioactive labels in accordance with their own trajectory, perhaps, should be considered a fact in favor of this hypothesis [Vernejoul, Darras et al., 1984]. In addition, G. Kellner [1966], having analyzed more than 10,000 layer-by-layer skin preparations, found that there are special cracks in the border zone between the stratum papillare and the for the transfer of energy through the skin.According to FZ Warren [1981], many of the BAPs, especially in the back, are similar in their action to trigger points, which often coincide with 3. Mechanisms of acupuncture Modern medicine prefers to use specific categories (morphological, physiological, biochemical, etc. ). In this regard, most studies of Western European scientists on the mechanism of acupuncture are aimed at studying certain aspects of acupuncture effects on the human body.Therefore, it is no coincidence that there are a significant number of theories of the mechanism of action of acupuncture. Tissue therapy theory. The main factors of influence are necrohormones and products of protein breakdown, formed during tissue injury at the site of needle insertion. The theory of normalization of capillary blood flow. In accordance with it, under the influence of acupuncture, the capillary blood flow is normalized, followed by the secondary elimination of the pathology of one or another organ. Theory of histamine alignment. During acupuncture, the content of histidine and the histamine formed from it is normalized reflexively through the corresponding segments of the spinal cord and the sympathetic part of the autonomic nervous system in the affected tissues of the diseased organ; as a result, there is an effect on the blood flow in the capillaries and the normalization of metabolism.Electrical theories: a) bioelectric currents arising during acupuncture have a therapeutic effect in connection with the phenomenon of resonance, i.e. when the wavelength and frequency of oscillations of the arising biocurrents coincide with similar indications of the tissues of the diseased organ; b) a change in the local electric charge when the needle is inserted into the acupuncture point (AT) affects the electric charge of the whole organism. The potential arising at the site of the needle impact and propagating along the canal serves as an additional stimulus to the primary point of impact and points located further along the canal.Vogralik V.G., Vogralik M.V. (1988) and Ionin M.V. (1961) note that the ancient doctrine of the importance of the metal of the needles for the effect of their action (the golden needle excites, the silver one calms down), on the basis of electrical theories, finds its explanation – the golden needle acts as a cathode, nichrome or silver – as an anode. At the same time, E.L. Macheret et al. (1989), like some other researchers (Gaponyuk P.Ya., Porov Yu.F., 1981), do not consider this mechanism of acupuncture to be the main one. Otherwise, it would be impossible to explain the effect of exposure to a bamboo, stone needle or finger massage.Thermoelectric concept. Romodanov A.L., Bogdanov G.B., Lyashchenko D.S. (1977, 1979, 1984), drawing attention to the thermoelectric primary mechanism of action of the acupuncture needle, note that the inserted needle is a kind of thermal probe and thus can affect the thermal homeostasis of the body as a whole. Since the needle is immersed in an electrolyte environment, due to the gradient of different temperatures, an electric potential arises on it, energetically most adequate for influencing the nervous system.At the same time, Romodanov A.P. with co-authors notes a two-phase change in temperature and, accordingly, the functional state of “points of influence” on the introduction of acupuncture needles: the first phase – excitement, accompanied by a local increase in temperature due to increased blood flow; the second phase is deceleration, accompanied by a local decrease in temperature. The lower thermal conductivity of gold needles in comparison with silver needles, according to the authors, increases their stimulating properties with the stimulating method of stimulation; the high thermal conductivity of silver needles with the appropriate method of their introduction contributes to the achievement of the inhibitory effect.However, the nature of the phenomenon that provides a therapeutic effect when exposed to certain areas of the skin is much more complicated than those local local changes that occur at the points of needle insertion. Ionic processes, the role of necrohormones, the release of histamine – all this cannot be considered as a serious basis for the mechanism of reflexology, not to mention the insignificant extent of these changes. The exaggeration of the importance of local factors contradicts all historical experience and those real mechanisms that underlie reflexotherapy (Durinyan R.A. et al., 1980). Bioelectric and energy information theories. A living organism, interacting with the environment, is forced to constantly adapt to the conditions and requirements of this environment, providing homeostasis. From a biophysical point of view, an organism is an energy system, in the existence of which electrical and electromagnetic processes are of great importance, occurring both in the environment and inside the body, as well as at their junction (Vogralik V.G., Vogralik M.V., 1988). It is assumed (Velkhover E.S., Nikiforov V.G., 1984; Nechushkin A.I., 1986; Vogralik V.G., Vogralik M.V., 1988) that information and energy exchange between macro- and microcosm is carried out mostly via AT. Limansky Yu.P. (1990) hypothesizes that AT are a specific system capable of adequately perceiving and transmitting signals to the brain about changes in the Earth’s electromagnetic fields and meteorological factors, calling it “ecoceptive sensitivity.” The system of ecoceptive sensitivity, notes Yu.P., is a special afferent input through which the body constantly monitors the qualitative and quantitative parameters of environmental factors, which in cases of significant deviations can change the activity of vital functional systems of the body. This information is integrated in the brain with similar information received through the viscerosensory sensory system from internal organs, and is used to trigger adaptive mechanisms aimed at weakening or completely compensating for negative changes in the functional systems of the body.The given data deserve the attention of specialists. In the course of subsequent research, the role of information and energy exchange between the body and the external environment during acupuncture will obviously be clarified, which will expand the possibilities of therapeutic effects. Hypnosis and acupuncture. Some doctors believe that acupuncture is a type of psychotherapy, a kind of “ritual hypnosis” or placebo. According to the modern, most widely accepted concept, hypnosis is an altered state of consciousness characterized by the ability to purposefully alter memory and perception.Hypnoanalgesia is considered as a special state of consciousness created by hypnosis, in which the process of awareness of the afferent flow of pain information is disturbed. This theoretical understanding of the mechanisms of hypnoanalgesia is consistent with the results of a number of experimental studies, which found that during hypnosis there is no actual inhibition of ascending nociceptive signals. Blood pressure remains elevated with nociceptive stimulation under hypnoanalgesia within the same range as in normal pain responses.Surgery under hypnosis is possible only in 10% of carefully selected patients, while the percentage of people who can undergo surgery under acupuncture analgesia is much higher. The fact that the analgesia caused by acupuncture cannot be explained by the effect of suggestion is also evidenced by the fact of successful treatment with acupuncture of diseases in domestic animals (Westemlayer E., 1978). At the II World Congress on Pain, evidence was presented that reflex action interferes with the passage of nociceptive signals in unconscious people (Ikesono E., 1978). Unlike psychotherapy, with acupuncture, a prerequisite for obtaining a therapeutic effect is irritation of somatic receptors and nerve fibers of the peripheral nervous system. One of the evidence is the fact that the preliminary introduction of local anesthetics into various AT completely blocks the effect of acupuncture (DIVomerans B., Cheng K., 1979). Reflex mechanisms of acupuncture. The reflex principle of acupuncture, moxibustion and other methods of influence on AT is.generally accepted. Many scientists adhered to the vegetative-reflex theory of acupuncture and moxibustion, developed by A.E. Shcherbak. (1936) in relation to physiotherapy. According to this theory, the main role in the mechanism of action of acupuncture belongs to the autonomic nervous system, skin-visceral relationships, etc. These data are not denied, but to date, in particular, the role of neurohumoral factors has been clarified, etc. Specific data on the reflex principle of acupuncture effects appeared in second half of the 20th century.(Fuye R., 1956; Stiefvater E., 1956; Wei Rushchu, 1957; Zhu-Lian, 1959, etc.). The mechanisms of action of acupuncture are basically similar to the reflex reactions studied in detail by I.M. Sechenov, I.P. Pavlov, N.E. Vvedensky, L.K. Anokhin, A.D. Speransky. and others, as well as refined in relation to physiotherapy by Shcherbak A.E., Kirichinsky A.R., Bogolyubov V.M., Ulashchik V.S. and others on cortical-subcortical formations, providing a general effect. A significantly high density of receptor formations, the participation of three to five spinal segments in the innervation of one metamere in these sections, their massive representation in cortical and subcortical centers – these facts explain mainly the general reflex (general strengthening) influence of distal points.The rapprochement of the points of view of classical acupuncture and European medicine is facilitated by the disclosure of the mechanism of action of auriculotherapy, where the dependence of the effect on the irritated zone is clearly traced: the effect on the zone innervated by the vagus nerve has a predominant effect on the visceral organs; the effect on the zone innervated by the trigeminal nerve has an analgesic effect, etc. Currently, data have been obtained that the response to acupuncture and other methods of influence on AT is realized through the nervous system with the inclusion of neurohumoral mechanisms.AT stimulation causes the most pronounced reflex reaction within that metamere or spinal segment in the corresponding internal organs with which the stimulated point is most closely connected. This principle, called “metameric reflexology”, has a clear neuroanatomical rationale, because individual spinal segments include not only the corresponding areas of the skin (dermatomes), but also the corresponding muscles (myotomes), bones and ligaments (sclerotomes), vessels and internal organs (enterotomes).These facts are known from the works of M.I. Astvatsaturov. (1929) and confirmed in relation to reflexology by A.K. Podshibyakin. (1960), Sudakov Yu.N. et al. (1986). They are based on the mechanism of convergence of different modal afferent impulses on the same neural elements. This explains the viscerosomatic and somatovisceral influences, which are most clearly manifested at the level of the spinal cord. Similar somatovisceral overlaps also take place in the overlying formations of the central nervous system, for example, at the level of the thalamus.Within the brain, somatovisceral relationships are more complex, and nevertheless they are objectively established in experimental models and confirmed by clinical observations. It was found that reflexology changes the excitability of brain neurons, stimulates the synthesis of various biologically active compounds, thereby blocking not only pain sensations, but also eliminating states of prolonged tension or excitement in various centers of the brain that control functions such as blood pressure, muscle tone, hormonal secretion, etc.The effectiveness of reflexology not only in the treatment of pain syndromes, but also in the treatment of hypertension, bronchial asthma, insomnia, various neuroses is associated with the restoration of dynamic balance between the processes of excitation and inhibition in the structures of the central nervous system under the influence of artificially evoked signals when exposed to AT. The primary trigger for acupuncture is irritation of receptor formations in the skin and underlying tissues. However, in contrast to general physiotherapeutic measures, acupuncture has a minimal impact zone.If irritation is applied with a needle, then it, penetrating into superficial and deeper tissues, affects various endings embedded in the skin, muscles, tendons, perivascular plexuses, nerve sheaths, etc. Stimulation of the receptor apparatus forms the response of the analyzer system; its strength depends on the degree, nature and duration of stimulation, as well as on the type of stimulated receptors. Stimulation of various peripheral nervous structures with an acupuncture needle determines a certain modality of the evoked (foreseen) sensations.Thus, the sensation of acute localized pain is associated with irritation of the A-delta fibers, followed by a diffuse dull pain sensation due to the involvement of the C fibers slowly conducting nerve impulses. A feeling of heaviness arises when the receptors sensitive to pressure are irritated, a feeling of fullness – as a result of changes in microcirculation and an increase in the permeability of the vascular wall, heat – due to increased microcirculation. Numbness is the result of local hypalgesia when an acupuncture needle is manipulated (Warren F., 1981). It is conditionally possible to distinguish the peripheral and central levels of the response to acupuncture. In the central, spinal, brainstem, hypothalamic and cortical levels are also distinguished. At the peripheral level, we are talking about irritation in one way or another of the dermal points and the corresponding receptor formations. In this case, a local reaction of the axon reflex type can develop with pallor or redness of the skin around the inserted needle, a change in local temperature, etc. AT stimulation can lead to a change in the microenvironment of receptors (smooth muscle tissue, blood capillaries, efferent sympathetic fibers) due to the release cells of prostaglandins, some enzymes, etc.The microenvironment of the receptors has a strong influence on their excitability. Some chemicals can excite nociceptors or make them more sensitive to other stimuli (sensitization), tendon and muscle nociceptors can be excited or sensitized by excessive tone of striated muscle tissue, etc. (Zimmerman M., 1981). However, it should be noted that the described reaction during acupuncture at the peripheral level does not have a significant value in the mechanisms of sanogenesis. It is only a trigger to turn on the central level.The response reaction when exposed to a particular point is not equivalent, which depends on the irritated structures, the zone of irritation and their connection with the central formations. For example, the impact of an acupuncture needle on the E (III) 9 point is in many ways similar to a reflex reaction when carotid chemoreceptors are excited. (This point is located above the bifurcation of the common carotid artery). When comparing the effects observed during transection of the radial, median and ulnar nerves in rats, it was found that with an intact radial nerve, the effect of acupuncture is more pronounced than when this nerve is cut, and the other two are intact (DIVomeran B., Cheng R., 1979). These data, indicating the greater efficiency of afferent signals traveling to the central nervous system along the radial nerve, help to better understand why the GI (II) 4 point, which lies directly above the site of the bifurcation of the superficial branch of the radial nerve, is so often used in the treatment of various diseases, while how other points of influence are selected in accordance with a specific nosology. The specificity of the zones of influence depends on the connection of the points with the organs and systems of the body. The action of acupuncture is due to the receipt of sensory information from the irritated receptor apparatus along the nerve to which the receptor formations belong, or along the perivascular nerve formations.A direct effect on the nerve trunk, ganglion, organ can be used, which takes place in some acupuncture techniques. However, the final response is associated with the central formations of the nervous system, the endocrine glands, i.e. at the level of the whole organism. The influence of acupuncture on the functioning of the spinal formations is quite diverse and is due to the neurophysiological characteristics of the spinal cord, as well as the strength of the stimulating signal, etc. In all cases, at the threshold value of the stimulus, the segmental apparatus with the corresponding segmental reaction is involved in the response.The latter is expressed by the direct reaction of the segment with the inclusion of fibers of the autonomic nervous system to various formations (internal organs, blood vessels, muscles, etc.). To obtain a stable segmental reaction, a certain exposure time is required, since short-term stimulation can result in a rapid attenuation of the reflex. (In classical acupuncture, inhibitory techniques are provided for in such cases). Apparently, in some cases, such a response is the main one in acupuncture, especially when it comes to the segmental influence of points.It is also possible that the therapeutic effect of the impact on the herald points, the Zakharyin-Ged zones, trigger points, just pain points has a similar connection at its core. As you know, the human body has a metameric principle of structure, which is an essential factor for understanding the mechanisms of acupuncture. Moreover, in the process of evolution, nature “reinsured” itself – each metamer is innervated not due to one segment, but is also overlapped by neighboring ones (upper and lower). Such phenomena are extremely important in the clinic.One can speak of the generality of vegetative-segmental innervation of internal organs and certain metameres when the same segments or the same vegetative formations serve as the source of innervation of an internal organ and a certain metamer. For example, the vegetative innervation of the head and face is carried out at the expense of the CVIII, – ThIII segments, while the somatic parts of these segments innervate mainly the hand, i.e. the same segments of the spinal cord are involved in the innervation (albeit different in nature) of various areas.These relationships can be of great importance in the practice of acupuncture. Probably, from this point of view, it is possible to explain, for example, the therapeutic effect of acupuncture at points GI (II) 4 or P (I) 7 for pain in the face and head. This mechanism, obviously, involves the trigeminal nerve system, the descending root of which sometimes reaches the CV segment (impulses can switch at this level). The possibility of such an influence is explained. List of recommended literature: 1. Agasarov L.G., Osipova N.N. A short guide to acupuncture – M., 1996. – 215p. 2. Vein A.M., Avrutskiy M.Ya. Pain and pain relief. – M .: Medicine, 1997 .– 280s. 3. Velhover E.S., Kushnir G.V. Extrareceptors of the skin. – Chisinau, 1983 .– 125p. 4. Velhover E.S., Nikiforov V.G. Fundamentals of Clinical Reflexology. – M .: Medicine, 1984 .– 224p. 5. Velhover E.S. Clinical iridology. – M .: Orbita, 1992 .– 432s. 6. Vogralik V.G. Fundamentals of the Chinese healing method zhen – chiu. – Gorky: Gorky Book Publishing House, 1961. – 320s.7. Vorontsova G.L. Reflexology in the prevention and treatment of obstetric complications. – Cheboksary, 1992 .– 120p. 8. Goidenko V.S., Koteneva V.M. A practical guide to reflexology. M .: TSOLIUV MH USSR. – 1982 .– 190s. 9. Durinyan R.A. Atlas of auricular reflexology. – Tashkent, 1982 .– 64p. 10. Durinyan R.A. Physiological foundations of auricular reflexology. – Yerevan, 1983 .– 240p. 11. Ivanichev G.A. Manual medicine. – M .: OOO “Medpress”, 1998. – 470s. 12. Ivanichev G.A. Manual therapy of muscular – fascial – skeletal pain.- Kazan, 1999 – 64p. 13. Ivanichev G.A. Sensory and reflex interaction in the mechanisms of acupuncture. – Kazan: Publishing house “Matbugat Yorty”. – 1999 .– 144s. 14. Ignatov Yu.D., Kachan A.T., Vasiliev Yu.N. Acupuncture analgesia: Experimental and clinical aspects. – L .: Nauka, 1990 .– 256s. 15. Kalyuzhny L.V. Physiological mechanisms of regulation of pain sensitivity. -M .: Medicine, 1984 .– 210s. 16. Kachan A.T., Bogdanov N.N., Varnakov P.Kh. etc. Anatomical – topographic location of corporal acupuncture points and indications for their use.- Voronezh: Voronezh University Publishing House, 1990. – 144p. 17. Krivenko V.V., Potebnya G.P. Iridology and its importance for herbal medicine. – Kiev: Nauk. dumka, 1988 .– 112s. 18. Lakusta V.N. Gross G.S. Brief basics of reflexology. – Chisinau, 1980 .– 195p. 19. Lakusta V.N. Lin Zhi Sheng Zhen – tszyu therapy of pain syndromes and emergency conditions. – Chisinau: “MAGA”, 1995. – 253p.

90,000 It’s Skin brand wiki | Squper

This article is about the outer cover of animals.For human skin, see human skin. For other uses, see Leather (disambiguation).

Skin is a soft outer tissue covering vertebrates with three main functions: protection, regulation, and sensation.

Other animal coatings, such as the arthropod exoskeleton, have a variety of origins, development, structure and chemical composition. Adjective cutaneous means “skin” (from Latin Cutis , skin). In mammals, the skin is an organ of the integumentary system, consisting of several layers of ectoderm tissue, and the guards of the major muscles, bones, ligaments, and internal organs. Skin of various natures exists in amphibians, reptiles and birds. All mammals have some amount of hair on their skins, even marine mammals such as whales, dolphins, and porpoises that appear to be bald.The skin interacts with the environment and is the first line of defense against external factors. For example, the skin plays a key role in protecting the body from pathogens and excessive water loss. Its other functions are thermal insulation, temperature regulation, burning sensation and the production of vitamin D, folate. Severely damaged skin can heal by forming tissue. It is sometimes discolored and depigmented. The thickness of the skin also varies from location to location on the body.For example, in humans, under the eyes and around the eyelids, the thinnest skin in the body is 0.5 mm thick, and is one of the first areas to show signs of aging such as crow’s feet and wrinkles. The skin on the palms and soles of the feet is 4 mm thick and the thick skin on the body. The speed and quality of skin healing is facilitated by the intake of estrogens.

Fur is thick hair. Primarily, fur increases the skin’s insulation, but can also serve as a secondary gender or camouflage.On some animals, the skin is very hard and thick, and can be processed to create leather. Reptiles and Pisces have tough protective scales on their skin for protection, and birds have tough feathers, all made of tough β-keratins. Amphibian skin does not have a strong barrier, especially with respect to the passage of chemicals through the skin and is often susceptible to osmosis and diffusion forces. For example, a frog sitting in an anesthetic solution will quickly shut off as the chemical diffuses through the skin. Amphibious skins play a key role in everyday survival and their ability to use a wide range of habitats and environmental conditions.

Structure in humans and other mammals

See also: human skin

( See also: rotating images (1.1 MB) )
Optical tomogram of the consistency of the finger, depicting the stratum corneum (~ 500 μm) with stratum corneum disjunctum on the top and lusidum (connecting to the spinosum layer) in the middle. At the bottom of the superficial part of the dermis. Sweatducts are clearly visible.

Mammalian skin consists of two main layers:

• in epidermis , which provides waterproofing and serves as a barrier to infection; and
• in dermis , which serves as a site for skin appendages;

Epidermis

Main article: epidermis

The epidermis consists of the stratum corneum.It forms a protective barrier on the surface of the body, is responsible for retaining water in the body and preventing pathogens from entering, and is a stratified squamous epithelium composed of proliferating basal and differentiated suprabasal keratinocytes.

Keratinocytes are the main cells making up 95% of the epidermis, while Merkel cells, melanocytes and Langerhans cells are present. The epidermis can be further subdivided into the following layers or layers (starting with the outer layer):

• Stratum corneum
• Interlayer lucidum (only on palms and soles)
• Spiny layers of the epidermis
• Layer spinosum
• Basal layer (also called epidermal growth layer )

Keratinocytes in the basal layer of the stratum proliferate through mitosis and daughter cells upward layers, changing shape and composition as they undergo several stages of cell differentiation to eventually become anucleated.During this process, keratinocytes will become highly organized, the formation of cellular junctions (desmosomes) between themselves and the secretion of keratin, proteins and lipids, which contribute to the formation of the extracellular matrix and provide mechanical strength to the skin. …

The epidermis does not contain blood vessels, and the cells in the deepest layers are nourished by diffusion from the capillaries of the blood, spreading to the upper layers of the dermis.

Basement membrane

Main article: basement membrane

The epidermis and dermis are separated by a thin sheet of fibers called the basement membrane, which is made through the action of both tissues.
The basement membrane regulates the movement of cells and molecules between the dermis and epidermis, and also serves by the binding of various cytokines and growth factors, as a reservoir for controlled release during physiological remodeling or repair processes.

Derma

Main article: dermis

B dermis is the layer of skin under the epidermis, which consists of connective tissue and cushions the body against stress and tension.The dermis provides skin strength and elasticity through the extracellular matrix of collagen fibrils, microfibrils, and elastic fibers embedded in hyaluronic acid and proteoglycans. Skin proteoglycans are diverse and have very specific locations. For example, hyaluronic acid, versican and decorina are found in the dermis and epidermis of the matrix, while biglycan and perlecan are found only in the epidermis.

It harbors many mechanoreceptors (nerve endings) that provide the sense of touch and warmth through nociceptors and thermoreceptors.It also contains hair follicles, sweat glands, sebaceous glands, apocrine glands, lymph vessels, and blood vessels. The blood vessels in the dermis provide nourishment and the removal of waste products from its own cells, as well as for the epidermis.

The dermis is closely related to the epidermis through the basement membrane and is structurally divided into two zones: the superficial area adjacent to the epidermis, called the papillary region , and the deep layer, known as the reticular region .

Papillary region

The papillary region is composed of loose connective tissue. This is called its finger-like projections, called papillae , which stretch towards the epidermis. The papillae give the dermis with a “bumpy” surface that interdigitates with the epidermis, strengthening the bonds between the two layers of the skin.

Reticular area

The reticular region lies deep in the papillary region and is usually much thicker. It consists of dense, irregular connective tissue and gets its name from the dense concentration of collagen, elastic and reticular fibers that weave throughout.These protein fibers give the dermis its properties of strength, extensibility and elasticity.
Also located in the reticular region are hair roots, sweat glands, sebaceous glands, receptors, nails and blood vessels.

Subcutaneous tissue

Main article: subcutaneous tissue

The subcutaneous tissue (also the hypodermis) is not part of the skin, and lies below the dermis. Its purpose is to attach the skin to the underlying bone and muscle, and to supply blood vessels and nerves.It consists of loose connective tissue and elastin. The main cell types are fibroblasts, macrophages and adipocytes (subcutaneous tissue contains 50% body fat). The fat serves as a cushion and insulation for the body.

Microorganisms such as Staphylococcus epidermidis colonize the surface of the skin. The density of the skin flora depends on the area of ​​the skin. The disinfected surface of the skin is repopulated with bacteria that live in the deeper parts of the hair follicle, intestines and urogenital opening.

Detailed section

Skin layers like hairy and hairless skin

Structure in fish, amphibians, birds and reptiles

Pisces

See also: fish scales

The epidermis of fish and most amphibians consists of living cells, with only minimal amounts of keratin in the cells of the surface layer. It is usually permeable, and in the case of many amphibians, it may actually be the primary respiratory organ. The dermis of teleost fish usually contains relatively little connective tissue found in tetrapods.Instead, in most species, it is largely replaced by hard, protective bony scales. With the exception of some particularly large integumentary bones that form parts of the skull, these scales are lost in tetrapods, although many reptiles have different kinds of weights, as do lizards. Cartilaginous fish have numerous tooth-like barbs embedded in their skin, in a place of true scale.

Sweat glands and sebaceous glands are unique to mammals, but other types of skin glands are found in other vertebrates.Fish tend to have many individual mucus-secreting skin cells that aid in isolation and defense, but may also have a poison gland, photophores, or cells that produce a more watery, serous fluid. In amphibians, mucus cells come together to form pouch-like glands. Most living amphibians also have granular glands of in the skin that secrete irritating or toxic substances.

Although melanin is found in the skin of many species, in reptiles, amphibians and fish, the epidermis is often relatively colorless.Instead, skin color is largely due to chromatophores in the dermis, which, in addition to melanin, may contain guanine or carotenoid pigments. Many species such as chameleons and flounders may be able to change their skin color by adjusting the relative sizes of their chromatophores.

Amphibians

See also: amphibians

Review

Amphibians have two types of glands, mucous and granular (serous). Both of these glands are part of the skin and are thus considered cutaneous.The mucous and granular glands are both divided into three different sections that connect to form the structure of the gland as a whole. The three separate parts of the gland are the ducts, the insertion areas, and finally the alveolar glands (Sac). Structurally, the conduit is excreted through the keratinocytes and passes through the surface of the epidermis or the outer layer of the skin, thus allowing external secretion of the body. An alveoli gland is a pouch-shaped structure that sits on the lower or base area of ​​the granular gland. The cells in this Sac are specialized in secretion.Between the alveolar gland and the ductal system is intercalary, which can be described as the transitional region connecting the canal to the great alveolar under the epidermal layer of the skin. In general, the granular glands are larger than the mucous glands, but the mucous glands conduct much more than most in general.

Frog gland anatomy- is: mucous glands (alveoli), B: chromophore, c: granular glands (alveoli), D: connective tissue, e: stratum corneum, F: transition zone (intercalary areas), d: epidermis (where lives of the top conductor), h: dermis

Granular glands

Granular glands can be defined as venomous and often differ in the type of toxin, as well as accumulation of secretions in different orders and species in amphibians.They are found in clusters of varying concentration depending on the amphibian taxa. Toxins can be fatal to most vertebrates or have no effect on others. These glands are alveolar-t. That is, they constructively have small sacs in which the poison is produced and spent before it is released for defensive behavior.

Structurally, air ducts made of granular iron initially retain their cylindrical shape. However, when the ducts become mature and full of toxic fluids, the bases of the ducts swell due to pressure from within.This results in the epidermal layer, forming pits, like a hole in the surface of the channel, in which the internal fluid will be released in an upward fashion.

The insertion areas of the granular glands are more developed in comparison with the mucous glands. This region is found in a ring of cells surrounding the basal duct, which is said to have an ectodermal muscular nature due to their effect on the lumen (space within you) with expansion and contraction of functions during discharge. The cells are located radially around the duct and provide a special attachment site for muscle fibers around the body of the gland.

The alveoli of the gland is a sac that is divided into three distinct regions / layers. The outer layer or sheath of osteodystrophy consists of densely packed connective tissue that connects with fibers from a porous intermediate layer where elastic fibers as well as nerves are located. Nerves send signals to muscles as well as epithelial layers. Finally, the epithelium and its own tunica albuginea of ​​the lining gland.

Mucous Glands

The mucous glands are non-venomous, and offer different possibilities for amphibians than granular ones.The mucous glands cover the entire surface of the amphibians’ body and specialize in keeping the body lubricated. There are many other functions of the mucous glands, such as pH regulation, thermoregulation, adhesion to the environment, anti-predator behavior (slippery to the hands), chemical bonds, even anti-bacterial / viral properties to protect against pathogens.

The ducts of the mucous glands look like cylindrical vertical you, which pierce the epidermis layer to the surface of the skin.The cells lining the inside of the ducts are oriented to their longitudinal axis, forming 90 degrees around the conduit in a spiral fashion.

The intercalary cells respond in the same way to those of the granular glands, but on a smaller scale. Among amphibians, there are taxa that contain modified intercalary regions (depending on the function of the gland), however most share the same structure.

In alveolor mucous glands are much simpler and consist only of a layer of epithelium and connective tissue, which forms a lid over the gland.This gland does not have a sheath of its own and appears to have thin and complex fibers that pass through the muscles, glands, and epithelial layers.

Birds and Reptiles

Main article: Reptile scales

The epidermis of birds and reptiles is closer to mammals, with a dead layer of keratin-filled cells on the surface to help reduce water loss. A similar pattern is also observed in some terrestrial amphibians such as toads. However, in all these animals there is no clear differentiation of the epidermis in separate layers, as is the case in humans, with a relatively gradual change in the type of cell.In mammals, the epidermis always possesses at least the growth layer of the epidermis and the stratum corneum, while the remaining intermediate layers in humans are not always distinguishable.
Hair is a distinctive feature of mammalian skin, while feathers (at least among living species) are also unique to birds.

Birds and reptiles have relatively few cutaneous glands, although there may be multiple structures for specific purposes, such as pheromone-secreting cells in some reptiles, or the uropygial glands in most birds.

Development

Skin structures of the epidermis arise and include various functions such as hair, feathers, claws and nails. During embryogenesis, the epidermis is divided into two layers: the peridermis (which has been lost) and the basal layer. The basal layer is the layer of stem cells and, through asymmetric divisions, becomes the source of skin cells throughout life. It functions as a stem cell layer through an autocrine signal, TNF-a, and through a paracrine signaling FGF7 aka keratinocyte growth factor (KGF) produced by the dermis beneath the basal cell.In mice, over-expression of these factors leads to an overproduction of grain cells and thick skin.

Hair and feathers add up to a pattern, and this is considered the result of the reaction-diffusion of the system. This reaction-diffusion system combines an activator, Sonic the Hedgehog, with an inhibitor, BMP4 or BMP2, to form clusters of cells in a pattern. Sonic hedgehog-expressing epidermal cells induce condensation of mesoderm cells. The accumulation of mesodermal cells signals back to the epidermis to form the appropriate structure for this position.BMP signals from the epidermis inhibit the formation of placodes in nearby ectoderms.

It is believed that the mesoderm defines the template. The epidermis allows the mesoderm cells to condense and then the mesoderm gives the epidermis, which composition, through a series of mutual inductions. Transplantation experiments involving frogs and Triton epidermis indicated that mesodermal signals persist between species, but the species-specific epidermal response means that the mesoderm gives the epidermis its position and the epidermis uses this information to make a specific structure.

Functions

Leather performs the following functions:

1. Protection: anatomical barrier against pathogens and damage between the internal and external environment in bodily protection. (See Skin Absorption.) Langerhans cells in the skin are part of the adaptive immune system.
2. Sensation: contains many nerve endings that jump to heat and cold, touch, pressure, vibration and tissue damage (see somatosensory system and perception, tactile).
3. Thermoregulation: Eccrine (sweat) glands and dilated vessels (increased surface perfusion) help heat loss, while constricted vessels significantly reduce cutaneous blood flow and retain heat. The rigger drank muscles in mammals to adjust the angle of the strands to change the degree of isolation provided for the hair or fur.
4. Evaporation control: The skin is a relatively dry and semi-impermeable barrier to reduce fluid loss.
5. Storage and Synthesis: acts as a storage center for lipids and water
6. Absorption through the skin: oxygen, nitrogen and carbon dioxide can diffuse into the epidermis in small amounts; some animals use their skin, and their sole is the respiratory organ (in humans, in cells consisting of the outer 0.25–0.40 mm of skin is “almost exclusively supplied by external oxygen” although “the contribution to total respiration is negligible”) some drugs are absorbed through the skin.
7. Water Resistance: The skin acts as a water-resistant barrier so that essential nutrients are not flushed out of the body. The outermost layer of the skin, the epidermis, covers the nutrients and oils that help moisturize the skin. It helped in part the sebaceous glands that release sebum, an oily liquid.Water alone will not lead to the elimination of oils on the skin, because oils residing in our dermis and can be affected by water without the epidermis.
8. Camouflage, whether the skin is bare or covered with hair, scales or feathers, the structures of the skin provide protective coloration and patterns that help hide animals from predators or prey.

Mechanics

Main article: soft tissue

Skin is a soft tissue and exhibits the key mechanical behavior of these tissues.The most pronounced feature is the stress-strain J-curve in the area of ​​large deformations and minimal stress exists and corresponds to microstructural straightening and reorientation of collagen fibers. In some cases, the intact skin is prestreched, like wet clothing around the diver’s body, and in other cases, the intact skin is compressed. The small round holes in the skin can expand or close into ellipses, or contract and remain round, depending on the existing stresses.

Aging

Tissue homeostasis tends to decrease with age, in part because stem / progenitor cells are unable to repair or differentiate themselves. In the skin of mice, mitochondrial oxidative stress can contribute to cellular senescence and senescent phenotypes. Usually mitochondrial superoxide dismutase (SOD2) protects against oxidative stress. Using a mouse model of genetic SOD2 deficiency, it has been shown that the inability to express this important antioxidant enzyme in epidermal cells results in cellular senescence, damage to nuclear DNA, and irreversible arrest of the proliferation of a portion of keratinocytes.

Skin aging is partially caused by TGF-β, which reduces the layer of subcutaneous fat, which gives the skin a pleasant look and texture. TGF-β does this by blocking the transformation of dermal fibroblasts into fat cells, with fewer fat cells underneath to provide support, the skin becomes saggy and wrinkled. Subcutaneous fat also produces cathelicidin, which is a peptide that fights bacterial infections.

Society and culture

The term “leather” can also refer to the covering of small animals such as sheep, goats (goats), pigs, snakes (snakeskin), etc.or a young large animal.

This term hides or rawhide refers to the covering of a large adult animal such as a cow, buffalo, horse, etc.

Hides and skins of various animals are used for clothing, bags and other consumer goods, usually in the form of leather, but also fur.

Leather from sheep, goats and cattle was used to make parchment for the manuscript.

The skin can also be cooked to make pork skins or crackles.

See also

• Anatomy portal

• Skin reflex in human locomotion
• Cutaneous respiration – gas exchange was carried out through the skin
• Molting
• Role of skin in locomotion
• Skins

Sympathetic nervous system – Russian

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The sympathetic nervous system (SNS) is one of the three divisions of the autonomic nervous system, the rest are the parasympathetic nervous system and the enteric nervous system.

The autonomic nervous system functions to regulate the body’s unconscious actions.The main process of the sympathetic nervous system is to stimulate the fight or the body’s response to flight. However, at a basic level, it is constantly active to maintain homeostasis. The sympathetic nervous system is described as antagonistic to the parasympathetic nervous system, which stimulates the body to “feed and reproduce” and (then) “rest and digest”.

Structure

There are two types of neurons involved in the transmission of any signal through the sympathetic system – preganglionic and postganglionic.Shorter preganglionic neurons arise in the thoracolumbar spinal cord specifically at T1 to L2 ~ L3, and travel to the ganglia, often one of the paravertebral ganglia, where they synapse with the postganglionic neuron. From there, long postganglionic neurons extend over most of the body.

At synapses within the ganglia, preganglionic neurons release acetylcholine, a neurotransmitter that activates nicotinic acetylcholine receptors on postganglionic neurons.In response to this stimulus, postganglionic neurons release norepinephrine, which activates adrenergic receptors present in peripheral target tissues. Activation of receptors in the target tissue induces effects related to the sympathetic system. However, there are three important exceptions –
Sweat gland postganglionic neurons release acetylcholine to activate muscarinic receptors, with the exception of areas of thick skin, palms and plantar surfaces of the feet, where norepinephrine is released and acts on adrenergic receptors.
Chromafin cells of the adrenal brain are similar to postganglionic neurons The adrenal brain develops in tandem with the sympathetic nervous system and acts as a modified sympathetic ganglion. Within this endocrine gland, preganglionic neurons synapse with chromaffin cells, causing the release of two transmitters — a small fraction of norepinephrine and, more importantly, epinephrine. The synthesis and release of epinephrine, in contrast to norepinephrine, is another distinguishing feature of chromaffin cells compared to postganglionic sympathetic neurons.
Postganglionic sympathetic nerves terminating in the kidney release dopamine, which acts on the dopamine D1 receptors in the blood vessels to control how much blood the kidneys filter. Dopamine is the direct metabolic precursor of norepinephrine, but it is nevertheless a separate signaling molecule.

Organization

e and has connections with the chest, abdominal and pelvic plexuses.
Sympathetic nerves arise near the middle of the spinal cord in the gray lateral intermediate nucleus, starting at the first thoracic vertebra of the vertebral column and believed to extend to the second or third lumbar vertebra.Since its cells originate in the thoracic and lumbar spinal cord, the sympathetic nervous system is said to have a thoracolumbar outflow. The axons of these nerves exit the spinal cord through the anterior root. They pass near the dorsal (sensory) ganglion, where they enter the front of the spinal nerve root. However, unlike somatic innervation, they are quickly detached through the white rami connectors (called the shiny white myelin sheaths around each axon), which connect to either the paravertebral (which lie close to the spinal column) or prevertebral (which lie near the bifurcation of the aorta) ganglia extending along the spinal column.
To reach target organs and glands, axons must travel long distances in the body, and in order to achieve this, many axons transmit their message to a second cell via synaptic transmission. The ends of the axons connect through space, the synapse, to the dendrites of the second cell. The first cell (presynaptic) sends a neurotransmitter through the synaptic cleft, where it activates the second cell (postsynaptic). The message is then transported to its final destination.
The axons of the presynaptic nerves terminate in either the paravertebral ganglia or the prevertebral ganglia.There are four different paths an axon can take before it reaches its final destination. In all cases, the axon enters the paravertebral ganglion at the level of its spinal nerve origin. After that, it can either synapse in this ganglion, ascend to a higher level or descend into the lower paravertebral ganglion and synapsis there, or it can descend into the prevertebral ganglion and synapse there from the postsynaptic cell.
The postsynaptic cell then continues to innervate the target end effector (i.e.e. gland, smooth muscle, etc.). Because the paravertebral and prevertebral ganglia are relatively close to the spinal cord, presynaptic neurons are generally much shorter than their postsynaptic counterparts, which must extend throughout the body to reach their destination.
A notable exception to the routes mentioned above is the sympathetic innervation of the adrenal (adrenal) brain. In this case, presynaptic neurons pass through the paravertebral ganglia, then through the prevertebral ganglia, and then synapse directly with the adrenal tissue.This tissue is made up of cells that have pseudo-neuronal qualities in that when a presynaptic neuron is activated, they release their neurotransmitter (epinephrine) directly into the bloodstream.
In the sympathetic nervous system and other components of the peripheral nervous system, these synapses are made at places called ganglia. The cell that sends its fiber is called the preganglionic cell, while the cell whose fiber leaves the ganglion is called the postganglionic cell.As mentioned earlier, the preganglionic cells of the sympathetic nervous system are located between the first thoracic segment and the third lumbar segment of the spinal cord. Postganglionic cells have their bodies in the ganglia and send their axons to target organs or glands.
The ganglia include not only the sympathetic trunks, but also the cervical ganglia (upper, middle and lower), which send sympathetic nerve fibers to the head and chest organs, and the mesenteric and mesenteric ganglia, which send sympathetic fibers to the intestines.

Information transfer

Messages pass through the sympathetic nervous system in a bidirectional flow. Efferent messages can simultaneously cause changes in different parts of the body. For example, the sympathetic nervous system can speed up the heartbeat, widen the bronchial passages, decrease the mobility (movement) of narrowed blood vessels in the colon, increase peristalsis in the esophagus, cause dilated pupils, piloerection (goose bumps) and sweating (sweating), and increase blood pressure.The exception is some blood vessels, such as those in the cerebral and coronary arteries, which dilate (rather than contract) with increased sympathetic tone. This is due to a proportional increase in the presence of β2 adrenergic receptors rather than α1 receptors. β2 receptors promote vasodilation, not vasoconstriction like α1 receptors. An alternative explanation is that the primary (and direct) effect of sympathetic stimulation on coronary arteries is vasoconstriction, followed by secondary vasodilation caused by the release of vasodilating metabolites due to sympathetically increased cardiac inotropy and heart rate.This secondary vasodilation, caused by primary vasoconstriction, is called functional sympatholysis, the general effect of which is to dilate the coronary arteries.
The target synapse of the postganglionic neuron is mediated by adrenergic receptors and is activated by either norepinephrine (norepinephrine) or epinephrine (adrenaline).

Function

The sympathetic nervous system is responsible for the regulation of many homeostatic mechanisms in living organisms. Fibers from innate CNS tissues in almost every organism, providing at least some regulation of functions as diverse as pupil diameter, intestinal motility, and urinary output and function.It is perhaps best known for mediating the neural and hormonal stress response known as the combat or flight response. This response is also known as the body’s sympatho-adrenal response, as preganglionic sympathetic fibers that end in the adrenal brain (but also all other sympathetic fibers) secrete acetylcholine, which activates a large secretion of adrenaline (epinephrine) and to a lesser extent norepinephrine (norepinephrine) from it … Therefore, this response, acting primarily on the cardiovascular system, is mediated directly by impulses transmitted through the sympathetic nervous system and indirectly through catecholamines secreted from the adrenal brain.
The sympathetic nervous system is responsible for fueling the body for action, especially in situations that threaten survival. One example of such a primer is moments before awakening, when sympathetic outflow spontaneously increases in preparation for action.
Sympathetic stimulation of the nervous system causes vasoconstriction in most blood vessels, including many in the skin, digestive tract, and kidneys. This occurs as a result of the activation of alpha-1 adrenergic receptors by norepinephrine released by postganglionic sympathetic neurons.These receptors exist throughout the choroid of the body, but are inhibited and balanced by beta-2 adrenergic receptors (stimulated by the release of epinephrine from the adrenal glands) in skeletal muscle, heart, lungs, and brain during the sympathoadrenal response. The cumulative effect of this is to cut off blood from organs that are not essential for the body’s immediate survival and increase blood flow to organs involved in intense physical activity.

Sensation

Afferent fibers of the autonomic nervous system, which transmit sensory information from the internal organs of the body back to the central nervous system (or CNS), are not divided into parasympathetic and sympathetic fibers, like efferent fibers – Moore, K.L., Agur, A.M. (2007). Essential Clinical Anatomy – Third Edition. Baltimore – Lippincott Williams Wilkins. 34-35. Instead, autonomic sensory information is conducted along common visceral afferent fibers.
General visceral afferent sensations are mainly unconscious visceral motor reflex sensations from hollow organs and glands that are transmitted to the central nervous system. While unconscious reflex arcs are usually not detected, in some cases they can send pain sensations to the central nervous system, disguised as so-called pain.If the peritoneal cavity becomes inflamed or if the intestine suddenly stretches, the body will interpret the afferent pain stimulus as somatic in origin. This pain is usually not localized. Pain also usually refers to dermatomes, which are located at the same level of the spinal nerve as the visceral afferent synapse.

Relationship with the parasympathetic nervous system

Together with another component of the autonomic nervous system, the parasympathetic nervous system, the sympathetic nervous system contributes to the control of most of the internal organs of the body.The stress response – both in flight and in combat – aims to counteract the parasympathetic system, which tends to keep the body at rest. The complex functions of both the parasympathetic and sympathetic nervous systems are not so simple, but this is a useful rule, which is the following

Disorders

In heart failure, the sympathetic nervous system increases its activity, leading to an increase in the strength of muscle contractions, which in turn increases the volume of the stroke, as well as peripheral vasoconstriction to maintain blood pressure.However, these effects accelerate the progression of the disease, ultimately increasing mortality in heart failure.
Sympathicotonia is Dorlan’s stimulated medical vocabulary for consumer health. 2007 a condition of the sympathetic nervous system characterized by vascular spasm, Citing- The American Heritage Medical Dictionary Copyright © 2007 high blood pressure and goose bumps. A recent study showed an expansion of natural Foxp3 + Treg in the bone marrow of mice after cerebral ischemia, and this myeloid expansion of Treg is associated with sympathetic stress signaling after cerebral ischemia.