How does the spinal cord structure relate to nerve function. What are the key components of the lumbar nervous system. How do spinal nerves innervate back muscles. What is the embryological development of the spinal cord. How does spinal cord anatomy impact clinical conditions.

The Intricate Structure of the Spinal Cord

The spinal cord is a complex structure that plays a crucial role in our nervous system. It consists of gray and white matter, each serving distinct functions. The gray matter, located centrally, contains cell bodies, while the white matter, found peripherally, houses myelinated tracts. This arrangement facilitates efficient signal transmission throughout the body.

Surrounding the spinal cord are three protective layers:

• Pia mater: The innermost layer
• Arachnoid mater: The middle layer
• Dura mater: The outermost layer, adhering to the spinal column

These layers, along with the subarachnoid space, provide crucial protection and support for the delicate neural tissue within.

Spinal Nerve Roots: The Bridge Between Central and Peripheral Nervous Systems

At each vertebral level, a bilateral pair of spinal nerve rootlets emerges from the spinal cord. These rootlets form sensory, motor, and mixed spinal nerves that innervate the surrounding musculature and skin. This intricate network allows for precise control and sensation throughout the body.

Lumbar Spine: The Powerhouse of the Back

The lumbar spine, consisting of five vertebral bodies, is designed for weight-bearing purposes. Its vertebral bodies are larger than those in the thoracic and cervical regions, providing stability and support for the lower back. This adaptation allows humans to maintain an upright posture and perform various physical activities.

Key Components of the Lumbar Nervous System

The lumbar nervous system comprises several essential elements:

• Lumbar spinal segments
• Spinal rootlets
• Spinal roots
• Spinal nerves

These components work together to ensure proper sensory and motor function in the lower back and legs. Understanding their relationships is crucial for diagnosing and treating various back-related conditions.

The Journey of Spinal Nerves: From Roots to Muscles

Spinal nerves follow a fascinating path from their origin in the spinal cord to their destinations in the body. This journey involves several key stages:

1. Posterior rootlets enter the spinal cord at the posterior horn
2. Anterior rootlets exit the spinal cord from the anterior horn
3. Posterior roots form posterior root ganglions
4. Anterior and posterior roots combine to form mixed spinal nerves
5. Mixed spinal nerves exit the spinal column through intervertebral foramina

This process ensures that both sensory and motor information can be transmitted efficiently between the central nervous system and the rest of the body.

The Role of Denticulate Ligaments

Denticulate ligaments play a crucial role in stabilizing spinal nerve roots within the vertebral column. These thin ligaments, formed by thickenings in the pia mater, attach to the arachnoid and dura mater. This arrangement helps maintain the proper positioning of each spinal nerve root, ensuring optimal function and reducing the risk of nerve compression or injury.

Lumbosacral Enlargement: A Hub of Neural Activity

The lumbosacral enlargement, spanning from T11 through S1 of the spinal cord, is a critical region for lower body function. This area gives rise to the anterior rami of the spinal nerves, which form the nerves of the lumbar and sacral plexus. These nerves are responsible for innervating the muscles and skin of the lower extremities, allowing for complex movements and sensations.

The Cauda Equina: A Unique Spinal Structure

The cauda equina, meaning “horse’s tail” in Latin, is a distinctive feature of the lower spinal cord. This cordlike structure is composed of thickened and elongated nerve roots that occupy the spinal canal below the conus medullaris (the tapered end of the spinal cord). The cauda equina extends to approximately the S2 vertebral level, where it attaches to the mid-sacral canal.

Embryological Development of the Spinal Cord: A Tale of Growth and Adaptation

The development of the spinal cord during embryogenesis is a fascinating process of growth and adaptation. Initially, the fetal spinal cord is the same length as the vertebral column. However, as the fetus grows, a remarkable change occurs: the vertebral column grows at a faster rate than the spinal cord.

This differential growth results in the adult spinal cord terminating at the L1 or L2 vertebral level, rather than extending the full length of the spinal column. This adaptation allows for greater flexibility and protection of the delicate neural tissue while still maintaining proper innervation of the lower body.

Implications for Clinical Practice

Understanding the embryological development of the spinal cord has important implications for clinical practice. For example, when performing lumbar punctures or administering epidural anesthesia, clinicians must be aware of the location of the conus medullaris to avoid potential injury to the spinal cord.

Spinal Cord Anatomy and Its Impact on Clinical Conditions

The intricate anatomy of the spinal cord and its surrounding structures plays a significant role in various clinical conditions. Understanding these relationships is crucial for accurate diagnosis and effective treatment of spinal disorders.

Herniated Discs and Nerve Root Compression

When a spinal disc herniates, it can compress nearby nerve roots as they exit the spinal column through the intervertebral foramina. This compression can lead to radiculopathy, causing pain, numbness, or weakness in the area innervated by the affected nerve. The specific symptoms and their location depend on which nerve root is compressed, highlighting the importance of understanding spinal cord anatomy in localizing the source of the problem.

Spinal Stenosis and the Cauda Equina Syndrome

Spinal stenosis, a narrowing of the spinal canal, can put pressure on the spinal cord or nerve roots. In severe cases, it can lead to cauda equina syndrome, a serious condition characterized by compression of the cauda equina. Symptoms may include lower back pain, leg weakness, and loss of bowel or bladder control. Prompt recognition and treatment of this condition are essential to prevent permanent neurological damage.

Advanced Imaging Techniques for Spinal Nerve Visualization

Modern medical imaging techniques have revolutionized our ability to visualize and diagnose spinal nerve disorders. These advanced tools allow clinicians to observe the intricate anatomy of the spinal cord and its associated structures with unprecedented detail.

Magnetic Resonance Imaging (MRI)

MRI is particularly useful for visualizing soft tissues, including the spinal cord, nerve roots, and intervertebral discs. It can provide detailed images of the spinal anatomy without exposing patients to ionizing radiation. MRI is often the imaging modality of choice for diagnosing conditions such as herniated discs, spinal stenosis, and tumors affecting the spinal cord or nerve roots.

Computed Tomography (CT) Myelography

CT myelography combines the benefits of CT scanning with the introduction of contrast material into the subarachnoid space. This technique provides excellent visualization of the spinal cord, nerve roots, and surrounding structures. It is particularly useful in cases where MRI is contraindicated or when more detailed images of bony structures are required.

Innovative Treatments Targeting Spinal Nerve Function

Advancements in our understanding of spinal nerve anatomy and function have led to the development of innovative treatments for various back-related conditions. These approaches aim to alleviate pain, improve function, and enhance quality of life for patients suffering from spinal disorders.

Neuromodulation Techniques

Neuromodulation involves the use of electrical or chemical stimulation to alter nerve activity. Spinal cord stimulation, for example, uses electrical impulses to modulate pain signals traveling through the spinal nerves. This technique has shown promise in treating chronic back pain and neuropathic pain conditions that have not responded to more conservative treatments.

Targeted Drug Delivery Systems

Intrathecal drug delivery systems allow for the direct administration of medications to the spinal cord and surrounding nerves. By bypassing the blood-brain barrier, these systems can deliver lower doses of medications with greater efficacy and fewer systemic side effects. This approach is particularly useful in managing severe chronic pain and spasticity associated with various spinal cord disorders.

The Future of Spinal Nerve Research and Treatment

As our understanding of spinal nerve anatomy and function continues to evolve, new avenues for research and treatment are emerging. These advancements hold promise for improving outcomes for patients with a wide range of spinal disorders.

Stem Cell Therapies for Spinal Cord Repair

Researchers are exploring the potential of stem cell therapies to repair damaged spinal cord tissue and restore function in patients with spinal cord injuries. While still in the experimental stages, these approaches could revolutionize the treatment of previously irreparable spinal cord damage.

Neuroprosthetics and Brain-Computer Interfaces

Advances in neuroprosthetics and brain-computer interfaces are opening up new possibilities for restoring function in patients with spinal cord injuries or neurodegenerative disorders affecting the spinal nerves. These technologies aim to bridge the gap between the brain and the body, allowing for improved control of paralyzed limbs or assistive devices.

As we continue to unravel the complexities of spinal nerve anatomy and function, we open doors to new possibilities in diagnosis, treatment, and rehabilitation of spinal disorders. The ongoing research and technological advancements in this field promise to bring hope and improved quality of life to millions of people suffering from back-related conditions worldwide.

Anatomy, Back, Spinal Nerve-Muscle Innervation – StatPearls

Hajira Basit; Vamsi Reddy; Matthew Varacallo.

Author Information and Affiliations

Last Update: April 8, 2023.

Introduction

The relevant anatomy of the innervation of the musculature of the back by the spinal nerves is centered around the lumbar spinal nerves, peripheral nerves of the lumbar plexus, spinal cord, and lumbar vertebral column.

In general, the spinal cord consists of gray and white matter. As in the brain, the gray matter of the spinal cord contains the cell bodies; the white matter of the spinal cord contains myelinated tracts. The gray matter of the spinal cord is found in the central aspect of the spinal cord. It is broadly in the shape of the capital letter H. Immediately surrounding the spinal cord is the pia mater, with the subarachnoid space overlying the pia mater, the arachnoid mater overlying the subarachnoid space, and dura mater at the outermost layer, adherent to the spinal column. [1][2] A bilateral pair of spinal nerve rootlets emerge from the spinal cord at each vertebral level, forming the sensory, motor, and mixed spinal nerves that innervate the regional musculature and skin.

Structure and Function

The cervical spine has eight cervical spinal segments and seven vertebral bodies. Within the lumbar region, the vertebral bodies are larger than in the thoracic and cervical regions; the lumbar spine is designed for weight-bearing purposes.[3] Each spinal cord segment generates a bilateral pair of corresponding spinal nerve roots. Each spinal cord segment corresponds to the same numbered vertebral level in the thoracic, lumbar, and sacral spinal regions. The primary components of the lumbar nervous system are the lumbar spinal segments, spinal rootlets, spinal roots, and spinal nerves.

The posterior horn is at the posterior aspect of the gray matter of the spinal cord. Components of the peripherally located white matter of the spinal cord are the posterior funiculus, lateral funiculus, anterior funiculus, and anterior commissure (which crosses the midline anteriorly). [4] The anterior horn is at the anterior aspect of the gray matter of the spinal cord. Located at the central aspect of the gray matter is the gray commissure (which crosses the midline). The transition from spinal roots to spinal nerves is at the level of the pedicle of the vertebral column. The posterior (dorsal) spinal roots enter the spinal column and form posterior root ganglions after separating from the motor fibers of the mixed spinal nerve. From distal to proximal: after the posterior root ganglion is the posterior spinal root, and then the posterior rootlets enter the spinal cord at the posterior horn [5]. The anterior (ventral) spinal rootlets exit the spinal cord from the anterior horn and then form the anterior spinal nerves. The anterior spinal nerves then combine with the posterior spinal roots (distal to the posterior root ganglion) to form mixed spinal nerves. The posterior spinal roots carry afferent (towards the spinal cord) sensory fibers, and the anterior spinal roots carry efferent (away from the spinal cord) motor fibers. Mixed spinal nerves are always a combination of sensory and motor nerves.[2]

Anterior spinal nerves carry motor fibers that affect motor nerves at the motor endplates of muscles. The lumbosacral enlargement is from T11 through S1 of the spinal cord. The lumbosacral enlargement gives off anterior rami of the spinal nerves, which make up the nerves of the lumbar and sacral plexus.[2]

The central canal of the spinal cord supplies the spinal cord and spinal nerves with cerebral spinal fluid (CSF) and is contiguous with the ventricular system of the brain, where the CSF is produced. CSF is present in the center of the gray matter, surrounding the spinal cord, in the subarachnoid space, and surrounding the spinal nerves.

There are five lumbar vertebral bodies, five lumbar spinal nerves, and five lumbar spinal segments. The adult spinal cord terminates at the L1 or L2 vertebral level. The terminal aspect of the spinal cord is the conus medullaris, and immediately inferior to the spinal cord is the cauda equina. The cauda equina is a cordlike structure composed of thickened and elongated nerve roots that occupy the spinal canal. The cauda equina attaches to the mid-sacral canal at approximately the level of the S2 vertebra.

Spinal nerves exit the spinal cord via the intervertebral foramen bilaterally at the lateral aspects of the vertebral column. Spinal nerves are secured by thickenings in the pia mater, forming thin ligaments called denticulate ligaments. Denticulate ligaments attach to the arachnoid and dura mater stabilizing the position of each spinal nerve root within the vertebral column.[1][2]

Embryology

During embryological development, the fetal spinal cord is the same length as the vertebral column. However, as the fetus grows, the vertebral canal elongates at a greater relative rate than the spinal cord. In adulthood, the spinal cord is shorter than the vertebral column and terminates at the conus medullaris, at the level of L1 or L2.[6]

Blood Supply and Lymphatics

Three lumbar vertebral arteries surround each lumbar vertebral body. Lumbar vertebral arteries are direct branches off of the aorta.[7] Spinal arterial branches differentiate into radicular and segmental arteries. Segmental arteries supply vertebral bodies, and posterior arterial branches supply vertebral arches.[8] Spinal branches enter the vertebral canal through intervertebral foramina to supply the bones, periosteum, ligaments, and meninges. Radicular and segmental arteries supply spinal nerve roots, spinal nerves, and the spinal cord. Venous drainage of the vertebral column parallels the arterial system. Additionally, there is an internal anterior lumbar venous plexus and a posterior external venous plexus.[2]

Nerves

Upon exiting the spinal column, the posterior and anterior spinal nerve roots combine around the intervertebral foramen to form mixed spinal nerves. The mixed spinal nerves contain both motor and sensory nerve fibers. Mixed spinal nerves immediately divide into two primary rami – a posterior ramus and an anterior ramus. The posterior and anterior rami contain both sensory and motor nerve fibers. Peripheral motor nerves usually contain up to 40% of sensory nerve fibers. Likewise, peripheral sensory nerves contain motor nerve fibers that innervate the smooth muscle of blood vessels, hair follicles, and sweat glands.[2]

Lumbar spinal nerves exit below their corresponding vertebral level. For example, an L1 spinal nerve will exit below the pedicle of the corresponding L1 vertebral body. Thoracic spinal nerves also exit below their corresponding vertebral level. However, in the cervical spine, the cervical nerves exit above their corresponding cervical vertebral level. For example, a C3 spinal nerve will exit above the pedicle of the C3 vertebral body.[2]

Muscles

A limited description of the specific lumbar spinal nerves includes: L1 innervates the abdominal internal obliques via the ilioinguinal nerve; L2-4 innervates the iliopsoas, a hip flexor, and other muscles via the femoral nerve; L2-4 innervates the adductor longus, a hip adductor, and other muscles via the obturator nerve; L5 innervates ankle dorsiflexion muscles.

The patellar reflex involves the L3/4 spinal nerves. The Achilles reflex involves the S1 spinal nerves.[2]

Physiologic Variants

A common physiologic variant of the lumbar spinal nerve root is a conjoined lumbosacral nerve root. In conjoined lumbosacral nerve roots, there are two nerve roots combined where the upper and lower spinal nerve roots are expected to be. Conjoined lumbosacral nerve roots result in an enlargement of the nerve root. Conjoined roots eventually divide and exit via separate foramina. Conjoined lumbosacral nerve roots can cause sciatica.

Redundant and anastomotic nerve roots are less common than conjoined nerve roots in the lumbosacral spine. Redundant or “twinned” nerve roots have two nerve roots exiting through a single intervertebral foramen. Anastomotic nerve root anomalies involve otherwise normal nerve roots with an anastomosis that bridges the connection between two adjacent roots.[9][10]

Surgical Considerations

Surgical intervention for low back pain should be reserved for cases refractory to more conservative treatment such as physical therapy and epidural injection. [11]

Clinical Significance

Back pain is a common complaint in medicine and is the number one cause of occupationally related-injury. 

Occupational workers older than the age of 40 are at a greater risk of developing back pain as compared to younger workers. A detailed, occupationally relevant medical history and physical examination are essential in accurately diagnosing and developing an appropriate treatment plan for back pain in the occupational setting.  

Often, an MRI of the lumbar spine is needed to make a definitive diagnosis in cases of persistent back pain. It is important to try correlating the patient’s symptoms with the imaging findings. The different types of back pain are local, referred, radicular, and spasmodic. The most common cause of back pain is a lumbar muscle spasm. In severe persistent back pain cases, lumbar disc disease with disc herniation/protrusion is more likely if there is an associated motor deficit. Nerve root entrapment from disc herniation/protrusion causes pain, possibly muscle spasms, and in many cases, an accompanying sensory and motor deficit is also seen. [12][13]

Imaging findings may not correlate with the patient’s symptoms. For example, a significant imaging finding of a right disc bulge at L5-S1 in a patient with symptoms of left L4-L5 nerve root distribution is a discordant finding. The anatomic correlation of disc protrusion with the affected spinal root or spinal nerve depends on the laterality of the disc protrusion. For example, a lateral disc protrusion at the L1-L2 vertebral level will most likely affect the L1 spinal nerve, whereas a central disc protrusion at the same level will most likely affect the L2 nerve root. This is due to the centrally traversing spinal nerve roots in the vertebral column and the lateral position of the exiting spinal nerves.

The likelihood of a disc protrusion or extrusion causing radicular symptoms or motor nerve deficit increase when there is preexisting central canal stenosis or intervertebral foramen narrowing. One example of radicular low back pain is sciatica (pain radiating from the low back down the posterior aspect of one or both lower extremities) which results from compression of the L5 and/or S1 component of the sciatic nerve (L5-S1).

The cause of central canal stenosis is multifactorial. Vertebral canal stenosis can result from facet hypertrophy, ligamentum flavum hypertrophy, disc bulge, and congenital canal stenosis. Approximately 95% of disc protrusions and extrusions occur at L4-L5 and/or L5-S1.[14] 

The differential diagnoses for back pain include but are not limited to degenerative disc disease, spinal tuberculosis or other infections, tumor, and abdominal aortic aneurysm. Although compression of the L4 spinal nerve is most likely secondary to disc herniation, the cause of nerve compression could also be from a different etiology, such as a spinal cord meningioma. A distinguishing imaging characteristic that can help to differentiate between disc bulge versus tumor or infection is leptomeningeal enhancement. Disc bulges would not show leptomeningeal enhancement, whereas a spinal tumor or discitis may show leptomeningeal enhancement.[15]

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Figure

Roots of the Spinal Nerve, Neurology, A spinal nerve with its anterior and posterior roots, Posterior and Anterior column, Anterior Medial fissure, Lateral Column. Contributed by Gray’s Anatomy Plates

Figure

The Spinal Nerves, Scheme showing structure of a typical spinal nerve, 1; Somatic efferent, 2; Somatic afferent, 3;4;5; Sympathetic efferent, 6;7; Sympathetic afferent. Contributed by Gray’s Anatomy Plates

Figure

The Lumbosacral Plexus, Plan of lumbar plexus. Contributed by Gray’s Anatomy Plates

Figure

A transverse slice through the thoracic region is shown in the picture. The rami communicantes are labeled and drawn as two nerves that anteriorly bridge the spinal nerve onto a ganglion of the sympathetic trunk. The white ramus communicans is the lateral (more…)

Figure

Lumbar disc extrusion. Contributed by Steve Lange, MD

References

1.

Devereaux M. Low back pain. Med Clin North Am. 2009 Mar;93(2):477-501, x. [PubMed: 19272519]

2.

Devereaux MW. Anatomy and examination of the spine. Neurol Clin. 2007 May;25(2):331-51. [PubMed: 17445732]

3.

Nordberg CL, Hansen BB, Nybing JD, Hansen P, Bliddal H, Griffith JF, Fournier G, Guglielmi G, Boesen M. Weight-bearing MRI of the Lumbar Spine: Technical Aspects. Semin Musculoskelet Radiol. 2019 Dec;23(6):609-620. [PubMed: 31745951]

4.

Alawieh A, Tomlinson S, Adkins D, Kautz S, Feng W. Preclinical and Clinical Evidence on Ipsilateral Corticospinal Projections: Implication for Motor Recovery. Transl Stroke Res. 2017 Dec;8(6):529-540. [PMC free article: PMC5802360] [PubMed: 28691140]

5.

Bican O, Minagar A, Pruitt AA. The spinal cord: a review of functional neuroanatomy. Neurol Clin. 2013 Feb;31(1):1-18. [PubMed: 23186894]

6.

Miao M, Lin X, Zhang Z, Zhao H. Normal development of the fetal spinal canal and spinal cord at T12 on 3. 0-T MRI. Acta Radiol. 2019 May;60(5):623-627. [PubMed: 30142995]

7.

Gailloud P. Spinal Vascular Anatomy. Neuroimaging Clin N Am. 2019 Nov;29(4):615-633. [PubMed: 31677734]

8.

Santillan A, Nacarino V, Greenberg E, Riina HA, Gobin YP, Patsalides A. Vascular anatomy of the spinal cord. J Neurointerv Surg. 2012 Jan 01;4(1):67-74. [PubMed: 21990489]

9.

Natsis K, Paraskevas G, Tzika M, Papathanasiou E. Variable origin and ramification pattern of the lateral femoral cutaneous nerve: a case report and neurosurgical considerations. Turk Neurosurg. 2013;23(6):840-3. [PubMed: 24310476]

10.

Böttcher J, Petrovitch A, Sörös P, Malich A, Hussein S, Kaiser WA. Conjoined lumbosacral nerve roots: current aspects of diagnosis. Eur Spine J. 2004 Mar;13(2):147-51. [PMC free article: PMC3476574] [PubMed: 14634853]

11.

Kovač V. Failure of lumbar disc surgery: management by fusion or arthroplasty? Int Orthop. 2019 Apr;43(4):981-986. [PubMed: 30426178]

12.

Kelsey JL. An epidemiological study of the relationship between occupations and acute herniated lumbar intervertebral discs. Int J Epidemiol. 1975 Sep;4(3):197-205. [PubMed: 1184269]

13.

Bartynski WS, Lin L. Lumbar root compression in the lateral recess: MR imaging, conventional myelography, and CT myelography comparison with surgical confirmation. AJNR Am J Neuroradiol. 2003 Mar;24(3):348-60. [PMC free article: PMC7973614] [PubMed: 12637281]

14.

Tarulli AW, Raynor EM. Lumbosacral radiculopathy. Neurol Clin. 2007 May;25(2):387-405. [PubMed: 17445735]

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Lucey BP, Tihan T, Pomper MG, Olivi A, Laterra J. Spinal meningioma causing diffuse leptomeningeal enhancement. Neurology. 2003 Jan 28;60(2):350-1. [PubMed: 12552066]

Disclosure: Hajira Basit declares no relevant financial relationships with ineligible companies.

Disclosure: Vamsi Reddy declares no relevant financial relationships with ineligible companies.

Disclosure: Matthew Varacallo declares no relevant financial relationships with ineligible companies.

Spinal Column & Spinal Nerve Chart

Your Spinal Column

Your spinal column or ‘backbone’ is made up of 24 vertebrae: seven in your neck (cervical spine), 12 in your midback (thoracic spine) and 5 in your lower back (lumbar spine). Your spinal cord, made up of billions of nerves, lies inside your spinal column, protected on all sides by bone. Your spinal nerves branch out through openings between your vertebrae and connect to your internal organs, muscles, joints, ligaments, tendons and other body parts. This connection is vital for your well-being.

The vertebral subluxation complex, an often painless spinal distortion, can irritate or damage your spinal nerves, interfere with your brain-body connection and affect your spine, nerves, discs, muscles, organs and overall health. Doctors of chiropractic specialize in the detection and correction of the vertebral subluxation complex – restoring the lines of communication within your body and improving your overall body function, healing potential and well-being.

C1: To blood supply to the head, pituitary gland, scalp, bones of the face, brain inner and middle ear, sympathetic nervous system, eyes, ears

C2: To eyes, optic nerves, auditory nerves, sinuses, mastoid bones, tongue, forehead, heart

 

C3: To cheeks, outer ear, face, bones, teeth, trifacial nerve, lungs

 

C4: To nose, lips, mouth, Eustachian tube, mucus membranes, lungs

 

C5: To vocal cords, neck glands, pharynx

 

C6: To neck muscles, shoulders, tonsils

 

C7: Tothyroid gland, bursa in the shoulders, elbows

 

T1: To arms from the elbows down, including hands, arms, wrists and fingers; esophagus and trachea, heart

 

T2: To heart, including its valves and covering coronary arteries; lungs bronchial tubes

 

T3: To lungs, bronchial tubes, pleura, chest, breast, heart

 

T4: To gallbladder, common duct, heart, lungs, bronchial tubes

 

T5: To liver, solar plexus, circulation (general), heart, esophagus, stomach

 

T6: To stomach, esophagus, peritoneum, liver, duodenum

 

T7: To kidneys, appendix, testes, ovaries, uterus, adrenal cortex, spleen, pancreas, large intestine

 

T8: To spleen, stomach, liver, pancreas, gallbladder, adrenal cortex, small intestine, pyloric valve

 

T9: To adrenal cortex, pancreas, spleen, gallbladder, ovaries, uterus, small intestine

 

T10: To kidneys, appendix, testes, ovaries, uterus, adrenal cortex, spleen, pancreas, large intestine

 

T11: To kidneys, ureters, large intestine, urinary bladder, adrenal medulla, adrenal cortex, uterus, ovaries, ileocecal valve

 

T12: To small intestine, lymph circulation, large intestine, urinary bladder, uterus, kdneys, ileocecal valve

 

L1: To large intesine, inguinal rings, uterus

 

L2: To appendix, abdomen, upper leg, urinary bladder

 

L3: To sex organs, uterus, bladder, knee, prostate, large intestine

 

L4: To prostate gland, muscles of the lower back, sciatic nerve

 

L5: To lower legs, ankles, feet, prostate

 

Sacrum: To hip bones, buttocks, rectum, sex organs, genitalia, urinary bladder, ureter, prostate

 

Sacral Plexus: Forms the sciatic as well as other nerves that go to muscles, joints and other structures of the legs, knees, ankles, feet and toes

 

Coccyx: To rectum, anus

“Emotional map” of the human body

At the annual meeting of the American Society of Neuroscience in Washington, behavioral neurologist Susannah Walker, from John Moores University of Liverpool, UK, presented a report on her research. Writes about it LiveScience.

The human brain analyzes all tactile sensations, we react to pain, heat, cold. There is also a connection between touch and emotional state, we respond positively to pleasant touches. Separate groups of nerves are responsible for the last reaction. Until recently, research on this topic was carried out mainly on animals. For example, in mice, “pleasure centers” were found on the back and slightly fewer on the limbs.

There are several different types of nerves in the human body that are responsible for touch. The thicker nerves, surrounded by a thick sheath, myelin, are responsible for touch and temperature and rapidly transmit these signals to the brain. Whereas thinner nerves, devoid of such a sheath, transmit sensory information more slowly. Scientists have identified a subclass of finer nerves called C-tactile afferents. They are responsible exclusively for gentle touches.

In the experiments conducted by Walker and her colleagues, the researchers stroked the subjects’ back, shoulder, forearm, and hand at different speeds. When people were asked to rate the degree of pleasure from each touch, they said that the most pleasant was the touch on the back, and the least pleasant was the touch on the forearm.

In the second part of the experiment, the scientists showed people a video recording of a person being gently stroked. The participants of the experiment said that there were no less positive emotions from viewing the recordings than from the very fact of touching. They imagined sensations in the back and shoulder, to a lesser extent in the forearm and palm.

Researchers believe that it is in these parts of the body that the groups of nerves responsible for positive tactile sensations are concentrated, the researcher says. There are more of these nerves in the back, and the least in the forearm.

These nerves respond more strongly to touches at a speed of 3-10 cm per second. It was their participants in the experiment that were noted as the most pleasant.

The results of the current study suggest that the nerve systems responsible for gentle touch form the basis of a person’s “emotional map”. Such data can be useful for medical and psychological treatment purposes. “For people of all walks of life, touch plays a fundamental role in the formation and maintenance of social bonds,” Walker says. “Undoubtedly, the lack of touch can have a negative effect on both our physical health and our mental state.”

Physical contact in early childhood is known to have a positive effect on a child’s development. In clinical settings, preterm infants who were not lacking in touch experienced accelerated development, decreased stress, and had a positive effect on brain development. But before Walker, few scientists looked for the root cause of such an observation in the nervous system.

In the future, Suzanne Walker and her colleagues plan to study the response of the facial muscles that make us smile to gentle touches to see where these sensations reflexively elicit pleasure.

Preview photo

Sciatica of the sciatic nerve: symptoms, treatment, diagnosis of the disease

Sciatica of the sciatic nerve is an inflammatory disease, which, according to the degree of discomfort it causes, is included in the list of the most painful human pathologies. The sciatic nerve is the largest nerve fiber in the human body, connecting the spinal column to the lower limb. It starts in the lumbar region and ends in the phalanges of the toes. It is a paired organ present in both lower extremities. When the nerve fiber is compressed, severe pain occurs, which is localized in the sacrum, spreads to the buttock, femoral part and lower down to the foot.

Symptoms of the disease

The most important symptoms of sciatica of the sciatic nerve are:

• pain localized in any part of the body along the passage of the nerve fiber: in the lower back, buttock, back of the thigh, lower leg, foot;
• loss of sensation, numbness of the lower limb along the nerve fiber;
• paresthesia – tingling sensations, “goosebumps” in the foot and toes.

The nature of the pain is most often shooting, but it can also be burning, dull, aching, etc. During periods of exacerbation, with movements of the spine or leg, it can intensify and become unbearable. As a rule, the disease affects one limb, but sometimes the pain appears in both legs at once. In the most severe cases, the disease leads to paralysis of the muscles of the leg, sometimes spreading to the muscles of the small pelvis, causing urinary and fecal incontinence in the patient.

Reasons

Sciatica of the sciatic nerve is a disease that can be caused by a number of causes of a vertebrogenic, i.e. associated with the spine, or non-vertebrogenic nature.

• Compression of the sciatic nerve or its branches is the most common cause of pain due to deformity, herniated disc, piriformis inflammation, or displacement of a vertebra.⁠
• Injuries to the lower spine, pelvis, or limb can result in nerve compression and nerve damage.
• Degenerative-dystrophic changes in the structure of the spine – osteochondrosis, spondylarthrosis – lead to compression of the sciatic nerve.
• Infectious diseases – scarlet fever, influenza, malaria, etc. – are accompanied by the release of toxins, leading to inflammation of the nerve fiber.
• Toxins that enter the body from the outside – at work, when drinking alcoholic beverages – can also cause inflammation.
• Systemic diseases – diabetes, gout, etc. – become the background for the appearance of pain.
• A malignant or benign tumor that compresses a nerve is another likely cause of the pathology.
• Hypothermia or excessive physical activity sometimes become the beginning of the inflammatory process.

Some experts single out the psychosomatics of sciatic nerve sciatica as a separate group of causes, believing that the disease can develop against the background of excessive psychological stress, stress, chronic fatigue, fear or phobia.

Diagnosis

This disease is characterized by a rather complicated diagnosis, the first stage of which is the conduct of reflexological tests for flexion and extension of the leg. To finally clarify the clinical picture, as necessary, appoint:

• laboratory tests;
• radiography of the affected area;
• MRI;
• CT;
• electroneuromyography;
• Ultrasound of the pelvic region.

The task of a neurologist is to identify symptoms characteristic of sciatica, and treatment should be aimed at eliminating the causes of nerve fiber compression.

Treatment

The choice of therapeutic methods depends on how severe the clinical manifestations of the disease are. When first contacting a neurologist, conservative methods of treating sciatica of the sciatic nerve prevail:

• non-steroidal anti-inflammatory drugs;
• hormonal preparations for the most severe cases;
• analgesics for pain relief;
• antispasmodics, muscle relaxants.

Great importance is attached to all kinds of physiotherapeutic methods, which are used both during exacerbations (UHF, electrophoresis, laser or magnetic therapy), and at their end.

Massage for sciatica is of great benefit, significantly prolonging the periods of remission. Depending on the nature of the squeezing factor, the patient may be prescribed a general massage to relax the spinal muscles, therapeutic, acupressure or cupping. In many cases, acupuncture sessions bring considerable benefits.

Therapeutic exercises for sciatica is another extremely useful technique that is widely used after the acute phase of the disease. Moderate physical activity aimed at strengthening the muscular corset and improving the blood supply to the tissues of the back, pelvis and limbs allows patients to maintain their body in good physical shape and prevent the recurrence of pain attacks.

Statistics

Sciatica of the sciatic nerve is a fairly common disease in the age group from 35 to 50 years. It is the most active age that accounts for the majority of primary visits to the doctor. The disease affects men more often than women. According to some experts, during the whole life, up to 40% of people have experienced at least once an attack of pain in the sacral part of the lower back, buttock or back of the thigh, but not all of these attacks become chronically protracted. Cases of visiting a doctor are about 20-25 people per 100 thousand of the population.

Diagnostics and treatment of sciatica of the sciatic nerve in Moscow

JSC “Medicina” invites Muscovites and guests of the capital for consultations on the diagnosis and treatment of sciatica of the sciatic nerve. At your service – the most modern diagnostic and physiotherapy equipment, as well as the qualifications and experience of medical personnel. In our clinic, neurologists and orthopedists of the highest category are treated, who will be able to relieve pain in the shortest possible time and return you to a full life. Call us to make an appointment with a specialist, or leave a request online on our website.

Questions and answers

Which doctor treats sciatica of the sciatic nerve?

If pain occurs, you should immediately contact a qualified neurologist in order to carry out the necessary diagnostic procedures and determine the best method for treating sciatica sciatica.

How to sleep with sciatica of the sciatic nerve?

Severe pain often interferes with healthy sleep. To reduce the likelihood of their occurrence, it is necessary to take care of an orthopedic mattress of moderate softness, on which the back will maintain a natural deflection during sleep. It is useful to put a small pillow or folded blanket under the sore leg. The pillow under the head should also be orthopedic, unloading the spine. The optimal position for sleeping is on your side, with a sore leg lying on a healthy one or next to it on a special pillow.

What to do with sciatica of the sciatic nerve?

If an attack of severe pain has begun, it is necessary, first of all, to fix the back with a thick scarf or scarf, then go to bed, take a comfortable position, and cover yourself with a warm blanket. To reduce pain, you can take a universal painkiller – ibuprofen, diclofenac, analgin, indomethacin. You should not self-medicate, as it can lead to an even more severe course of the disease.