Central Nervous System: The Brain and Spinal Cord (for Parents)

en español: Sistema nervioso central: Cerebro (encéfalo) y médula espinal

Reviewed by: Larissa Hirsch, MD

Primary Care Pediatrics at Nemours Children’s Health

The nervous system has two parts: the central nervous system and the peripheral nervous system.

What Is the Central Nervous System?

The central nervous system is made up of the brain and spinal cord:

• The brain controls how we think, learn, move, and feel.
• The spinal cord carries messages back and forth between the brain and the nerves that run throughout the body.

Both the brain and the spinal cord are protected by bone: the brain by the bones of the skull, and the spinal cord by
vertebrae, a set of ring-shaped bones. They’re both cushioned by layers of membranes (called meninges) and cerebrospinal fluid. The fluid flows through hollow spaces in the brain called ventricles and around the spine in the spinal column. It protects the central nervous system, nourishes it, and takes away waste products.

What Does the Central Nervous System Do?

The brain is like a central computer that controls all the body’s functions. It is in charge of what we think and feel, how we learn and remember, and the way we move and talk. It also controls things we’re less aware of — like the beating of our hearts and the digestion of our food. The brain sends messages back and forth with the body. These messages travel through the spinal cord.

What Are the Parts of the Brain?

The brain is very complex and very compact. An adult’s brain weighs only about 3 pounds. It has many folds and grooves that store important information. The main parts of the brain are the cerebrum, the brainstem, and the cerebellum.

The Cerebrum

The cerebrum (seh-REE-brum) is the biggest part of the brain. A large part of the cerebrum is the cerebral cortex (also known as “gray matter”).

The cortex has four areas called lobes that work together to create a person’s personality and everything they know. Each lobe processes a different kind of information:

• The frontal lobe is involved in complex thinking, like planning, imagining, making decisions, and reasoning. It’s located behind the forehead.
• The parietal (peh-RYE-et-el) lobe processes information about touch, taste, and temperature. It’s behind the frontal lobe.
• The temporal lobe lets us understand sounds and language, recognize objects and faces, and create memories. It’s near the ears.
• The occipital (ok-SIP-it-el) lobe processes light and other visual information from the eyes, letting us know what we’re seeing. It’s in the rear part of the brain.

The cerebrum has two halves, called hemispheres. A band of nerve fibers (the corpus callosum) connects them in the middle, which lets them exchange information. The left hemisphere controls the movements of the right side of the body. The right hemisphere of the brain controls the movements of the left side of the body.

The Brainstem

The brainstem connects the brain and the spinal cord. It is made up of the pons, the medulla (meh-DULL-uh), and the midbrain. These parts work together to control and coordinate the messages going in and out of the brain. The brainstem also controls many body functions that we often don’t think about — like breathing, heart rate, blood pressure, swallowing, and digestion.

The Cerebellum

Behind the cerebrum is the cerebellum (sair-uh-BELL-um). The cerebellum — also called the “little brain” because it looks like a small version of the cerebrum — is responsible for balance, movement, and coordination.

Other Structures in the Brain

Many other smaller parts of the brain do important jobs, including:

• The thalamus, which receives messages about the senses, like vision, hearing, and touch coming from the eyes, ears, and fingers.
• The hypothalamus, which controls the pulse, thirst, appetite, sleep patterns, and other processes that happen automatically.
• The pituitary gland, which makes hormones that control growth, metabolism, water and mineral balance, sexual maturity, and response to stress.

What Are the Parts of the Spinal Cord?

The spinal cord is a long bundle of nerve tissue. In an adult, it’s about 18 inches long and 1/2-inch thick. It extends from the lower part of the brainstem down the back.

The spinal cord has three sections that run the length of the spine. Each section’s name describes the part of the spine it passes through: cervical (SER-vih-kul), thoracic (theh-RAH-sik), and lumbar-sacral (LUM-ber SAK-rul). They send off smaller nerves to parts of the body nearby:

• The cervical spinal cord sends nerves to the face and neck.
• The thoracic spinal cord sends nerves to the arms, chest, and abdomen.
• The lumbar-sacral spinal cord sends nerves to the lower body.

A bunch of nerves — called cauda equina because they look like a horse’s tail — is at the bottom of the spinal cord.

Reviewed by: Larissa Hirsch, MD

Date reviewed: July 2022

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Central nervous system: Structure, function, and diseases

The central nervous system (CNS) consists of the brain and spinal cord. It controls things like thought, movement, and emotion, as well as breathing, heart rate, hormones, and body temperature.

CNS is referred to as “central” because it combines information from the entire body and coordinates activity across the whole organism.

This article briefly overviews the CNS. It looks at the types of cells involved, different regions within the brain, spinal circuitry, and how the CNS can be affected by disease and injury.

Fast facts on the central nervous system

Here are some key points about the central nervous system. More detail and supporting information are in the main article.

• The CNS consists of the brain and spinal cord.
• The brain is the most complex organ in the body and uses 20% of the total oxygen we breathe.
• The brain consists of an estimated 100 billion neurons connected to thousands more.
• The brain can be divided into four main lobes: temporal, parietal, occipital, and frontal.

The CNS consists of the brain and spinal cord.

The brain is protected by the skull (the cranial cavity) and the spinal cord travels from the back of the brain, down the center of the spine, stopping in the lumbar region of the lower back.

The brain and spinal cord are housed within a protective triple-layered membrane called the meninges.

The central nervous system has been thoroughly studied by anatomists and physiologists, but it still holds many secrets; it controls our thoughts, movements, emotions, and desires. It also controls our breathing, heart rate, the release of some hormones, body temperature, and much more.

The retina, optic nerve, olfactory nerves, and olfactory epithelium are sometimes considered to be part of the CNS alongside the brain and spinal cord. This is because they connect directly with brain tissue without intermediate nerve fibers.

Below is a 3D map of the CMS. Click on it to interact and explore the model.

Now we will look at some of the parts of the CNS in more detail, starting with the brain.

The brain is the most complex organ in the human body; the cerebral cortex (the outermost part of the brain and the largest part by volume) contains an estimated 15–33 billion neurons, each of which is connected to thousands of other neurons.

In total, around 100 billion neurons and 1,000 billion glial (support) cells make up the human brain. Our brain uses around 20% of our body’s total energy.

The brain is the central control module of the body and coordinates activity. From physical motion to the secretion of hormones, the creation of memories, and the sensation of emotion.

To carry out these functions, some sections of the brain have dedicated roles. However, many higher functions — reasoning, problem-solving, creativity — involve different areas working together in networks.

The brain is roughly split into four lobes:

Temporal lobe (green): important for processing sensory input and assigning it emotional meaning.

It is also involved in laying down long-term memories. Some aspects of language perception are also housed here.

Occipital lobe (purple): visual processing region of the brain, housing the visual cortex.

Parietal lobe (yellow): the parietal lobe integrates sensory information including touch, spatial awareness, and navigation.

Touch stimulation from the skin is ultimately sent to the parietal lobe. It also plays a part in language processing.

Frontal lobe (pink): positioned at the front of the brain, the frontal lobe contains the majority of dopamine-sensitive neurons and is involved in attention, reward, short-term memory, motivation, and planning.

Brain regions

Next, we will look at some specific brain regions in a little more detail:

Basal ganglia: involved in the control of voluntary motor movements, procedural learning, and decisions about which motor activities to carry out. Diseases that affect this area include Parkinson’s disease and Huntington’s disease.

Cerebellum: mostly involved in precise motor control, but also in language and attention. If the cerebellum is damaged, the primary symptom is disrupted motor control, known as ataxia.

Broca’s area: this small area on the left side of the brain (sometimes on the right in left-handed individuals) is important in language processing. When damaged, an individual finds it difficult to speak but can still understand speech. Stuttering is sometimes associated with an underactive Broca’s area.

Corpus callosum: a broad band of nerve fibers that join the left and right hemispheres. It is the largest white matter structure in the brain and allows the two hemispheres to communicate. Dyslexic children have smaller corpus callosums; left-handed people, ambidextrous people, and musicians typically have larger ones.

Medulla oblongata: extending below the skull, it is involved in involuntary functions, such as vomiting, breathing, sneezing, and maintaining the correct blood pressure.

Hypothalamus: sitting just above the brain stem and roughly the size of an almond, the hypothalamus secretes a number of neurohormones and influences body temperature control, thirst, and hunger.

Thalamus: positioned in the center of the brain, the thalamus receives sensory and motor input and relays it to the rest of the cerebral cortex. It is involved in the regulation of consciousness, sleep, awareness, and alertness.

Amygdala: two almond-shaped nuclei deep within the temporal lobe. They are involved in decision-making, memory, and emotional responses; particularly negative emotions.

The spinal cord, running almost the full length of the back, carries information between the brain and body, but also carries out other tasks.

From the brainstem, where the spinal cord meets the brain, 31 spinal nerves enter the cord.

Along its length, it connects with the nerves of the peripheral nervous system (PNS) that run in from the skin, muscles, and joints.

Motor commands from the brain travel from the spine to the muscles and sensory information travels from the sensory tissues — such as the skin — toward the spinal cord and finally up to the brain.

The spinal cord contains circuits that control certain reflexive responses, such as the involuntary movement your arm might make if your finger was to touch a flame.

The circuits within the spine can also generate more complex movements such as walking. Even without input from the brain, the spinal nerves can coordinate all of the muscles necessary to walk. For instance, if the brain of a cat is separated from its spine so that its brain has no contact with its body, it will start spontaneously walking when placed on a treadmill. The brain is only required to stop and start the process, or make changes if, for instance, an object appears in your path.

The CNS can be roughly divided into white and gray matter. As a very general rule, the brain consists of an outer cortex of gray matter and an inner area housing tracts of white matter.

Both types of tissue contain glial cells, which protect and support neurons. White matter mostly consists of axons (nerve projections) and oligodendrocytes — a type of glial cell — whereas gray matter consists predominantly of neurons.

Also called neuroglia, glial cells are often called support cells for neurons. In the brain, they outnumber nerve cells 10 to 1.

Without glial cells, developing nerves often lose their way and struggle to form functioning synapses.

Glial cells are found in both the CNS and PNS but each system has different types. The following are brief descriptions of the CNS glial cell types:

Astrocytes: these cells have numerous projections and anchor neurons to their blood supply. They also regulate the local environment by removing excess ions and recycling neurotransmitters.

Oligodendrocytes: responsible for creating the myelin sheath — this thin layer coats nerve cells, allowing them to send signals quickly and efficiently.

Ependymal cells: lining the spinal cord and the brain’s ventricles (fluid-filled spaces), these create and secrete cerebrospinal fluid (CSF) and keep it circulating using their whip-like cilia.

Radial glia: act as scaffolding for new nerve cells during the creation of the embryo’s nervous system.

The cranial nerves are 12 pairs of nerves that arise directly from the brain and pass through holes in the skull rather than traveling along the spinal cord. These nerves collect and send information between the brain and parts of the body – mostly the neck and head.

Of these 12 pairs, the olfactory and optic nerves arise from the forebrain and are considered part of the central nervous system:

Olfactory nerves (cranial nerve I): transmit information about odors from the upper section of the nasal cavity to the olfactory bulbs on the base of the brain.

Optic nerves (cranial nerve II): carry visual information from the retina to the primary visual nuclei of the brain. Each optic nerve consists of around 1.7 million nerve fibers.

Below are the major causes of disorders that affect the CNS:

Trauma: depending on the site of the injury, symptoms can vary widely from paralysis to mood disorders.

Infections: some micro-organisms and viruses can invade the CNS; these include fungi, such as cryptococcal meningitis; protozoa, including malaria; bacteria, as is the case with Hansen’s disease (leprosy), or viruses.

Degeneration: in some cases, the spinal cord or brain can degenerate. One example is Parkinson’s disease which involves the gradual degeneration of dopamine-producing cells in the basal ganglia.

Structural defects: the most common examples are birth defects; including anencephaly, where parts of the skull, brain, and scalp are missing at birth.

Tumors: both cancerous and noncancerous tumors can impact parts of the central nervous system. Both types can cause damage and yield an array of symptoms depending on where they develop.

Autoimmune disorders: in some cases, an individual’s immune system can mount an attack on healthy cells. For instance, acute disseminated encephalomyelitis is characterized by an immune response against the brain and spinal cord, attacking myelin (the nerves’ insulation) and, therefore, destroying white matter.

Stroke: a stroke is an interruption of blood supply to the brain; the resulting lack of oxygen causes tissue to die in the affected area.

Difference between the CNS and peripheral nervous system

The term peripheral nervous system (PNS) refers to any part of the nervous system that lies outside of the brain and spinal cord. The CNS is separate from the peripheral nervous system, although the two systems are interconnected.

There are a number of differences between the CNS and PNS; one difference is the size of the cells. The nerve axons of the CNS — the slender projections of nerve cells that carry impulses — are much shorter. PNS nerve axons can be up to 1 meter long (for instance, the nerve that activates the big toe) whereas, within the CNS, they are rarely longer than a few millimeters.

Another major difference between the CNS and PNS involves regeneration (regrowth of cells). Much of the PNS has the ability to regenerate; if a nerve in your finger is severed, it can regrow. The CNS, however, does not have this ability.

The components of the central nervous system are further split into a myriad of parts. Below, we will describe some of these sections in a little more detail.

What is the central nervous system

You may already know that your central nervous system (CNS) is one of the most important parts of your body. It sends and receives messages between the brain and the rest of the body through nerve cells, or neurons, that carry these messages.

WHAT IS THE CENTRAL NERVOUS SYSTEM?

Your CNS allows you to think, feel and move. She is responsible for everything – from breathing and heartbeat to touch and taste. It coordinates your movements and actions and helps you respond to your environment. Living a daily life without a healthy central nervous system would be very difficult.

CENTRAL NERVOUS SYSTEM VS. PERIPHERAL NERVOUS SYSTEM

all nerves from the brain and spinal cord to the rest of the body . Together, these two systems make up the so-called nervous system.

The central nervous system is responsible for processing information and coordinating the activities of your body. To do this, it sends and receives signals from the peripheral nervous system. The peripheral system, in turn, relays messages back and forth between the central nervous system and the rest of your body. This is one of the exciting joint operations that takes place in your body every second, even when you sleep.

BRAIN AND SPINAL CORD

The brain and spinal cord are parts of the central nervous system. Think of the brain as the headquarters for all bodily activity: it sends commands to the rest of the body via the spinal cord. The brain consists of four main parts: cerebrum, diencephalon, cerebellum and brainstem, each of which is divided into areas responsible for different functions.

On the other side is the spinal cord. The spinal cord is a long thin tube of nerves that runs from the brain down to the lower back, well protected by the vertebrae of the spine. The cranial nerves also branch off from the brain and connect it to the eyes, ears, nose, and other parts of the head.

TWO HEMISPHERES

The human brain is divided into two halves called cerebral hemispheres. A bundle of nerve fibers called the corpus callosum connects these two parts of the brain. Each hemisphere receives sensory information and transmits motor information to the opposite side of the body.

Each hemisphere has areas specialized for different functions. For example, language and internal thought processes are more controlled by the left hemisphere, while emotional and non-verbal processes are more controlled by the right. Quite often, the differences between the left and right hemispheres are exaggerated in popular media, but in general we use both sides of our brain equally.

CEREBRUM

The cerebrum is the dominant part of the brain responsible for consciousness, movement and more complex cognitive processes such as reasoning and decision making.

The cerebral cortex is the outermost and most significant part of the brain. It consists of four lobes with specific functions:

Frontal lobe: problem solving and judgment, expressive language, personality and fine motor control.

Parietal lobe: processing of somatosensory information such as touch, temperature and body position.

Occipital lobe: visual processing, center of the brain.

Temporal lobe: auditory processing and language comprehension.

The brain also contains other important structures such as the hippocampus (learning and memory formation), the amygdala (emotion processing), and the basal ganglia (regulation of movement and behavior).

DIENCEPHALON

Diencephalon is located deep in the brain and contains the thalamus and hypothalamus. The thalamus is the main center for the transmission of sensory and motor information to and from the brain. It also helps regulate sleep and consciousness. The hypothalamus is responsible for maintaining homeostasis and maintains normal levels such as heart rate, body temperature and hormones.

CEREBELLUM

The cerebellum is located under the brain and controls balance and posture. It cannot initiate muscle contractions, but provides smoothness and coordination of volitional movements.

BRAINSTEM

The brainstem connects the brain to the spinal cord and consists of three parts. The medulla oblongata is directly connected to the spinal cord. It controls automatic functions such as breathing and blood pressure, as well as reflex actions such as coughing, swallowing, and vomiting. The pons is the middle segment of the brainstem and is responsible for balance and posture. The midbrain sits just below the brain and controls eye movements.

WHAT IS THE NERVOUS SYSTEM FAQ

WHAT IS THE MAIN FUNCTION OF THE CENTRAL NERVOUS SYSTEM?

The central nervous system is responsible for processing information and coordinating the activities of your body. To do this, it sends and receives signals from the peripheral nervous system.

WHAT ARE THE SEVEN MAIN PARTS OF THE CENTRAL NERVOUS SYSTEM?

The seven main parts of the CNS are the brain, spinal cord, cerebrum, cerebellum, medulla oblongata, pons and thalamus.

WHAT CAN DAMAGE THE CENTRAL NERVOUS SYSTEM?

Common diseases affecting the CNS include Alzheimer’s disease, Parkinson’s disease and multiple sclerosis. Acute events that may affect the CNS include strokes and traumatic injuries to the brain or spine. CNS health naturally declines with age, but it can be affected by lifestyle factors such as stress, poor diet, smoking, sleep deprivation, and lack of exercise.

HOW CAN I PROTECT MY CENTRAL NERVOUS SYSTEM?

There are many things you can do to protect your CNS from harm. Some tips include: eating healthy, exercising regularly, not smoking or drinking too much alcohol, getting enough sleep, and managing stress effectively.

• Stress: Chronic stress leads to elevated cortisol levels, inflammation in the peripheral and central nervous system, and dysfunction of protective immune cells in the CNS called microglia, all of which contribute to cognitive impairment and dementia.
• Sleep: Poor and inadequate sleep is associated with cognitive impairment and neuroinflammation. Even one night of sleep deprivation can significantly increase the amount of substances in the brain called Aβ plaques, which increase inflammation and contribute to the development of Alzheimer’s disease.
• Exercise: Regular physical activity may prevent cognitive decline with age and is associated with a 45% reduced risk of developing Alzheimer’s disease. You should aim for 30 minutes of moderate-intensity aerobic exercise five days a week or 20 minutes of vigorous aerobic exercise three days a week.
• Diet and Gut Health: The Mediterranean diet slows cognitive decline in normal aging and promotes a healthy gut microbiota by reducing inflammation in the CNS. You can also protect your gut health by making sure you get enough omega-3 fatty acids, zinc, iron, and vitamins D, A, and E.

WHAT HAPPENS WHEN THE CENTRAL NERVOUS SYSTEM IS DAMAGED?

If the CNS is damaged it can cause many symptoms. Some common problems include problems with movement, balance, and coordination; problems with memory, thinking and behavior; problems with sensation and touch.

HOW TO CURE THE CENTRAL NERVOUS SYSTEM?

There is no universal answer to this question. The best way to heal the CNS depends on the problem causing the damage. However, some general recommendations for a healthy central nervous system include: a healthy diet, regular exercise, avoiding smoking and excessive drinking, getting enough sleep, and managing stress effectively.

• Exercise: Regular aerobic activity improves cognition, reduces neuroinflammation, and induces positive anatomical and physiological changes in the brains of people with mild aging-induced cognitive decline and even early stage Alzheimer’s disease.
• Diet and Gut Health: A healthy diet supports the health benefits of physical activity. Probiotics and faecal transplantation restore normal microglial function and reduce Aβ plaques in mouse models of Alzheimer’s disease. Vitamin D supplementation may help improve cognitive function in Alzheimer’s patients.

Resources

https://www.ncbi.nlm.nih.gov/books/NBK442010/

https://www.ncbi.nlm.nih.gov/books/NBK542179/

https://www.ncbi.nlm.nih.gov/books/NBK537247/

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3897366/

https://www .ncbi.nlm.nih.gov/books/NBK538167/

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7234821/

https://www.ncbi.nlm.nih.gov /pmc/articles/PMC7498620/

https://pubmed.ncbi.nlm.nih.gov/pmc/articles/PMC8126018/

Structure of the central nervous system • Medmost

To understand more about tumors of the spinal cord and brain , you need to know the general structure and functions of the central nervous system (central nervous system).

There are centers in the brain that are responsible for higher nervous activity, sensations, emotions, memory, speech, vision, hearing, motor activity, breathing and much more.

The spinal cord and spinal nerves provide communication between the brain and the rest of the body. They transmit signals that tell our muscles how to move, help coordinate the work of internal organs and the body as a whole.

The brain is located in the cranium, which provides its protection, the spinal cord, in the same way, protects the bones of the spine.

The brain and spinal cord are immersed in a special (cerebrospinal) fluid that keeps them safe and nourished. Cerebrospinal fluid is produced by the choroid plexuses located in the so-called ventricles of the brain. The spaces inside the skull and the ventricles of the brain are filled with cerebrospinal fluid.

What is the brain and spinal cord made of?

The brain consists of the cerebral hemispheres, the cerebellum and the brain stem. Each part performs its specific functions.

Cerebral hemispheres is the largest outer part of the brain, which is divided into left and right hemispheres and is responsible for thinking, emotions and speech. There is also a control center for voluntary muscle movements (throwing a ball, walking, chewing), perception and interpretation of information from the sense organs – vision, hearing, smell, touch, pain receptors.

The cerebellum – is located under the cerebral hemispheres and is responsible for the coordination of movements.

Brain stem – the lower parts of the brain connected to the spinal cord. Long nerve fibers pass through it, which transmit signals from the brain to muscles and internal organs and vice versa. Here are the centers that control breathing and heart activity, most of the spinal nerves also begin in the brain stem.

The brainstem is divided into 3 main parts: the midbrain, the pons and the medulla oblongata. Due to the small size and the presence of centers here that are responsible for vital functions, surgical removal of tumors is usually impossible here.

The cranial nerves originate at the base of the brain and carry signals from the brain to the sense organs.

The spinal cord consists of bundles of long nerve fibers that are responsible for the innervation of motor muscles, body sensation, bladder and bowel control.

Hypothalamus and pituitary gland. The pituitary gland is a pineal gland located at the base of the brain. It is connected with the hypothalamus, together with which it ensures the production of hormones that regulate the activity of the endocrine glands:

• control the amount of thyroid hormones produced;
• control the amount of hormones produced for breastfeeding;
• control the amount of produced male or female sex hormones;
• control the amount of growth hormone produced;
• control the amount of vasopressin produced, which regulates the exchange of water in the kidneys.

Growth of tumors in the pituitary or hypothalamus, as well as surgery, chemotherapy or radiation therapy can disrupt these organs and cause hormonal disorders in the body. For example, tumors growing in the pituitary gland can lead to the production of too many hormones. Sometimes, on the contrary, after treatment, the level of hormones in a person decreases and he needs to take them additionally.

The pituitary or pineal gland is not really part of the brain. This is a small gland that belongs to the endocrine system and is located between the hemispheres of the brain. It is responsible for the production of melatonin, a hormone that regulates sleep. The most common tumors are called pineoblastomas.

Blood Brain Barrier: is an inner sheath that is made up of small blood vessels (capillaries) and creates a semi-impermeable barrier separating the circulatory system from the brain and spinal cord. This barrier helps maintain metabolic balance in the brain and prevents harmful substances from entering the brain. Unfortunately, it also prevents drugs used for chemotherapy from reaching the brain.

The choroid plexus is an area of ​​the brain located in the ventricles and is responsible for producing cerebrospinal fluid that nourishes and protects the brain.

The brain and spinal cord are made up of many types of tissues and cells from which various types of tumors can develop.

Neurons (nerve cells): are brain cells that are responsible for mental activity, memory, emotions, speech, skeletal muscle movements, perception of sensations and much more.

Unlike many cell types that can grow and divide over a lifetime, recovering from injury or disease, neurons in the brain and spinal cord generally stop dividing about a year after they start (with a few exceptions). Neurons do not usually form tumors, but they are often damaged by growing tumors that have grown nearby.

Glial cells: supporting cells of the brain. Most brain and spinal cord tumors develop from glial cells. These tumors are sometimes referred to as gliomas .

There are 3 main types of glial cells:

• Astrocytes are responsible for supporting and nourishing neurons. When the brain is damaged, astrocytes form scar tissue that helps repair the damage. The main tumors starting in these cells are called astrocytomas or glioblastomas .
• Oligodendrocytes form myelin, a fatty substance that surrounds and insulates nerve cells in the axons of the brain and spinal cord. This helps neurons transmit electrical signals through axons. Tumors that start in these cells are called oligodendrogliomas .
• Ependymal cells line the ventricles (fluid-filled areas) within the brain and form part of the pathway through which CSF flows. Tumors starting in these cells are called ependymomas .

Microglia are cells of the immune system that are responsible for fighting infection in the CNS. They are not glial cells.

Neuroectodermal cells – are cells that are precursors to other types of cells in the nervous system.