What Is the Central Nervous System (CNS)? (2023)

The central nervous system (CNS) is comprised of the brain and spinal cord. The three broad functions of the CNS are to take in sensory information, process information, and send out motor signals.

The CNS receives sensory information from the nervous system and controls the body's responses. The central nervous system plays a primary role in receiving information from various areas of the body and then coordinating this activity to produce the body's responses.

The CNS is differentiated from the peripheral nervous system, which involves all of the nerves outside of the brain and spinal cord that carry messages to the CNS.

This article discusses the structures that make up the central nervous system and how they function. It also explores some of the diseases and conditions that can affect the CNS.

Central Nervous System Structure

The CNS has three main components: the brain, the spinal cord, and the neurons (or nerve cells). Each part of the CNS plays an important role in how the body functions, and the three components of the CNS work together to take in information and control how the body responds.

The Brain

The brain controls many of the body's functions including sensation, thought, movement, awareness, and memory. The surface of the brain is known as the cerebral cortex. The surface of the cortex appears bumpy thanks to the grooves and folds of the tissue. Each groove is known as a sulcus, while each bump is known as a gyrus.

The largest part of the brain is the cerebrum. It is responsible for functions such as memory, speech, voluntary behaviors, and thought.

The cerebrum is divided into two hemispheres, the right hemisphere and the left hemisphere. The right hemisphere controls movements on the body's left side, while the left hemisphere controls movements on the body's right side.

While some functions do tend to be lateralized, researchers have found that there are not "left brained" or "right brained" thinkers, as the old myth implies. Both sides of the brain work together to produce various functions.

Each hemisphere of the brain is then divided into four interconnected lobes:

  • Frontal lobes are associated with higher cognition, voluntary movements, and language.
  • Occipital lobes are associated with visual processes.
  • Parietal lobes are associated with processing sensory information.
  • Temporal lobes are associated with hearing and interpreting sounds as well as the formation of memories.

Other important areas of the brain include the basal ganglia, cerebellum, Broca's area, corpus callosum, medulla oblongata, hypothalamus, thalamus, and amygdala.

Recap

The brain is the part of the central nervous system that controls many of the functions of the body, including movement, thought, learning, and awareness.

Spinal Cord

The spinal cord connects to the brain via the brain stem and then runs down through the spinal canal, located inside the vertebrae. The spinal cord carries information from various parts of the body to and from the brain.

While it varies from one individual to the next, the spinal cord is about 18 inches in length. At the brainstem, 31 spinal nerves enter into the spinal cord. The nerves of the spinal cord consist of:

  • 8 cervical nerves
  • 12 thoracic nerves
  • 5 lumbar nerves
  • 5 sacral nerves
  • 1 coccygeal nerve

In the case of some reflex movements, responses are controlled by spinal pathways without involvement from the brain. Examples include the Golgi tendon reflex, the crossed extensor reflex, and the stretch reflex.

(Video) Overview of the Central Nervous System (CNS)

Recap

The spinal cord carries information from the brain to the rest of the body and transmits signals from the body to the brain.

Neurons

Neurons are the building blocks of the central nervous system. Billions of these nerve cells can be found throughout the body and communicate with one another to produce physical responses and actions.

Most neurons are divided into three basic sections: dendrites, cell body, and axon. These cells also differ in terms of function. The three types of neurons are afferent neurons, efferent neurons, and interneurons.

Efferent neurons are motor neurons that carry signals from the brain to the peripheral nervous system. Afferent neurons are sensory neurons that bring information from the senses to the brain. Interneurons are association neurons that connect efferent and afferent neurons to the central nervous system.

Recap

Neurons are the cells that make up the central nervous system. They are responsible for communicating information throughout the body.

Protective Structures

Since the CNS is so important, it is protected by a number of structures. First, the entire CNS is enclosed in bone. The brain is protected by the skull. The spinal cord is encased by the vertebrae that make up the spinal column.

The brain and spinal cord are both covered with a protective tissue known as meninges. There are three layers of meninges protecting the brain and spinal cord:

  • Dura mater: From the Latin words meaning "hard mother," this is the top layer of the meninges found directly under the bones of the skull and vertebrae. It is composed of dense connective tissue.
  • Arachnoid mater: The second layer of the meninges is a spider-like, transparent membrane made up of collagen and elastic fibers.
  • Pia mater: From the Latin for "soft mother," this protective layer is the innermost layer of the meninges. It is made of delicate connective tissue that is filled with tiny blood vessels that provide nourishment for the brain.

The entire CNS is also immersed in a substance known as cerebrospinal fluid, which forms a chemical environment that allows nerve fibers to transmit information effectively as well as offering yet another layer of protection from potential damage.

Recap

The CNS is protected by structures including the skull, spinal vertebrae, meninges, and cerebrospinal fluid.

Diseases of the Central Nervous System

There are a number of problems and diseases that can affect the CNS. Damage or disease to the central nervous system can produce a range of effects. Some of the conditions that can impact the CNS include:

  • Degenerative diseases: Diseases such as Parkinson's disease and Alzheimer's disease can cause the degeneration of cells in pivotal areas of the brain, affecting functions such as movement and memory.
  • Infections: Viruses, bacteria, and fungi can invade the central nervous system, causing symptoms and/or damage.
  • Stroke: A blockage of blood flow to the brain prevents oxygen from reaching the tissues of the brain. This results in damage to the affected area and can lead to impairment or death.
  • Trauma: Injury to the CNS can cause a number of problems ranging from paralysis to death.
  • Tumors: Cancerous and benign tumors can grow in different areas of the CNS. The impact of these tumors depends on their location and size.

Recap

A variety of diseases and other problems can affect the CNS, including infections, trauma, tumors, and degenerative conditions. Such diseases and damage can lead to impairment and sometimes death.

(Video) Central Nervous System: Crash Course Anatomy & Physiology #11

Central Nervous System (CNS) Depression: Definition, Symptoms, Causes, Treatment

Frequently Asked Questions

  • How are gray and white matter arranged in the CNS?

    The outer cortex of the brain is composed of gray matter, while the inner part of the brain is made up of white matter. The gray matter is primarily made of neurons, while the white matter contains cell axons. Both the white and gray matter contain glial cells that support and protect the neurons of the brain.

  • Can the central nervous system repair itself?

    The structures that make up the CNS are delicate and susceptible to damage, injury, and disease. Because these structures are so complex, the damage is usually permanent. Researchers are exploring treatments, including medications and therapies, that may help repair damage to the CNS and restore functioning.

  • What causes paralysis?

    Paralysis is caused by problems with the nervous system. Movement depends on signals from the brain being able to reach areas of the body; damage to the nervous system interferes with the body's ability to transmit motor and movement messages. Congenital conditions, strokes, spinal cord injuries, brain injuries, neurological diseases, and autoimmune diseases are all potential causes of paralysis.

8 Sources

Verywell Mind uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.

  1. American Association of Neurological Surgeons. Anatomy of the brain.

  2. Nielsen JA, Zielinski BA, Ferguson MA, Lainhart JE, Anderson JS. An evaluation of the left-brain vs. right-brain hypothesis with resting state functional connectivity magnetic resonance imaging. PLoS ONE. 2013;8(8):e71275. doi:10.1371/journal.pone.0071275

  3. American Association of Neurological Surgeons. Anatomy of the spine and peripheral nervous system.

  4. Herculano-Houzel S. The human brain in numbers: a linearly scaled-up primate brain. Front Hum Neurosci. 2009;3:31. doi:10.3389/neuro.09.031.2009

  5. Kayalioglu G. The vertebral column and spinal meninges. In: The Spinal Cord. Elsevier; 2009:17-36. doi:10.1016/B978-0-12-374247-6.50007-9

  6. Moini J, Piran P. Meninges and ventricles. In: Functional and Clinical Neuroanatomy. Elsevier; 2020:95-129. doi:10.1016/B978-0-12-817424-1.00004-5

  7. Nagappan PG, Chen H, Wang DY. Neuroregeneration and plasticity: a review of the physiological mechanisms for achieving functional recovery postinjury.Mil Med Res. 2020;7(1):30. doi:10.1186/s40779-020-00259-3

  8. Cleveland Clinic. Paralysis.

What Is the Central Nervous System (CNS)? (1)

By Kendra Cherry
Kendra Cherry, MS, is an author and educational consultant focused on helping students learn about psychology.

(Video) The Nervous System In 9 Minutes
(Video) The Central Nervous System: The Brain and Spinal Cord

FAQs

What is CNS short answer? ›

The central nervous system (CNS) is made up of the brain and spinal cord. It is one of 2 parts of the nervous system. The other part is the peripheral nervous system, which consists of nerves that connect the brain and spinal cord to the rest of the body. The central nervous system is the body's processing centre.

What is the central nervous system CNS responsible for? ›

The central nervous system CNS is responsible for integrating sensory information and responding accordingly. It consists of two main components: The spinal cord serves as a conduit for signals between the brain and the rest of the body. It also controls simple musculoskeletal reflexes without input from the brain.

What is an central 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.

What are the 4 main functions of the central nervous system? ›

The four main functions of the nervous system are:
  • Control of body's internal environment to maintain 'homeostasis' An example of this is the regulation of body temperature. ...
  • Programming of spinal cord reflexes. An example of this is the stretch reflex. ...
  • Memory and learning. ...
  • Voluntary control of movement.

Where is the central nervous system in the brain? ›

It's the top part of the brainstem, which connects the brain to the spinal cord.

What controls the nervous system? ›

The brain is what controls all the body's functions. The spinal cord runs from the brain down through the back. It contains threadlike nerves that branch out to every organ and body part. This network of nerves relays messages back and forth from the brain to different parts of the body.

Why is the nervous system important? ›

The nervous system plays a role in nearly every aspect of our health and well-being. It guides everyday activities such as waking up; automatic activities such as breathing; and complex processes such as thinking, reading, remembering, and feeling emotions. The nervous system controls: Brain growth and development.

Why is it called the central nervous system? ›

The central nervous system consists of the brain and spinal cord. It is referred to as “central” because it combines information from the entire body and coordinates activity across the whole organism.

What is the main function of the central nervous system Brainly? ›

The central nervous system CNS is responsible for integrating sensory information and responding accordingly. It consists of two main components: The spinal cord serves as a conduit for signals between the brain and the rest of the body. It also controls simple musculoskeletal reflexes without input from the brain.

Are there nerves in the CNS? ›

The central nervous system (CNS) includes the nerves in the brain and spinal cord. It is safely contained within the skull and vertebral canal of the spine. All of the other nerves in the body are part of the peripheral nervous system (PNS).

What are the 2 types of nervous systems? ›

The nervous system has two main parts: The central nervous system is made up of the brain and spinal cord. The peripheral nervous system is made up of nerves that branch off from the spinal cord and extend to all parts of the body.

What are the two types of nervous system cells? ›

Although the nervous system is very complex, there are only two main types of cells in nerve tissue. The actual nerve cell is the neuron. It is the "conducting" cell that transmits impulses and the structural unit of the nervous system. The other type of cell is neuroglia, or glial, cell.

What are 5 organs in the nervous system? ›

The nervous system consists of the brain, spinal cord, sensory organs, and all of the nerves that connect these organs with the rest of the body. Together, these organs are responsible for the control of the body and communication among its parts.

What is a main organ of nervous system? ›

The brain and spinal cord are the organs of the central nervous system. Because they are so vitally important, the brain and spinal cord, located in the dorsal body cavity, are encased in bone for protection.

What is nervous system parts and functions? ›

The brain and the spinal cord make up the central nervous system. The nervous system is the most complex and highly organized body system. It receives information from the sensory organs via nerves, transmits the information through the spinal cord, and processes it in the brain.

What is the function of the brain? ›

The brain is a complex organ that controls thought, memory, emotion, touch, motor skills, vision, breathing, temperature, hunger and every process that regulates our body. Together, the brain and spinal cord that extends from it make up the central nervous system, or CNS.

Which fruit is good for nerve? ›

Berries, peaches, cherries, red grapes, oranges and watermelon, among others, are loaded with antioxidants, which help to decrease inflammation and reduce nerve damage. Plus, grapes, blueberries and cranberries have been found to be full of a powerful anti-inflammatory compound called resveratrol.

What is another name for a nerve cell? ›

A type of cell that receives and sends messages from the body to the brain and back to the body. The messages are sent by a weak electrical current. Also called neuron.

What are nerve signals? ›

Nerves are like cables that carry electrical impulses between your brain and the rest of your body. These impulses help you feel sensations and move your muscles. They also maintain certain autonomic functions like breathing, sweating or digesting food. Nerve cells are also called neurons.

How many nerves do we have in our body? ›

Believe it or not, there are over 7 trillion nerves in the human body. All these nerves are part of what's known as your body's nervous system. You can think of nerves as your body's electrical wiring — they transmit signals between your brain, spinal cord, and the rest of your body.

What is a fact about the nervous system? ›

The nervous system is the body's inner communication system. It's made up of the body's many nerve cells. The nerve cells take in information through the body's senses: touch, taste, smell, sight, and sound. The brain interprets these sensory cues to understand what's going on outside and inside the body.

What is central nervous system class 10? ›

CNS or central nervous system- It comprises the brain and spinal cord. The brain acts like a computer which controls all the functions of our body. The brain is the centre of thoughts, intelligence, and memory. It processes the information received by the nerves.

What is the difference between the PNS and CNS? ›

The CNS is made up of the brain and the spinal cord components. The PNS is all the nerves that branch out from the CNS components and extend to other parts of the body – to the sense organs, muscles, and glands. The PNS connects the CNS to the rest of the body.

What is the brain for? ›

The brain is the most complex part of the human body. This three-pound organ is the seat of intelligence, interpreter of the senses, initiator of body movement, and controller of behavior.

What is the nervous system called? ›

Central nervous system (CNS): Your brain and spinal cord make up your CNS. Your brain uses your nerves to send messages to the rest of your body. Each nerve has a protective outer layer called myelin. Myelin insulates the nerve and helps the messages get through.

What are the components of the CNS central nervous system )? Class 10? ›

The Central Nervous System comprises two parts: The brain and spinal cord.

Is there a nucleus in the CNS? ›

In neuroanatomy, a nucleus (plural form: nuclei) is a cluster of neurons in the central nervous system, located deep within the cerebral hemispheres and brainstem.

What are the two main parts of the central nervous system? ›

The central nervous system is made up of the brain and spinal cord. The peripheral nervous system is made up of nerves that branch off from the spinal cord and extend to all parts of the body.

Why are nerves so important? ›

The nervous system plays a role in nearly every aspect of our health and well-being. It guides everyday activities such as waking up; automatic activities such as breathing; and complex processes such as thinking, reading, remembering, and feeling emotions.

What are types of nerve cells? ›

Although the nervous system is very complex, there are only two main types of cells in nerve tissue. The actual nerve cell is the neuron. It is the "conducting" cell that transmits impulses and the structural unit of the nervous system. The other type of cell is neuroglia, or glial, cell.

What are nerves made of? ›

Your nerves are made up of: Axons, cord-like groups of fibers in the center of your nerve. Dendrites, branches that carry electrical impulses. Endoneurium, a layer of connective tissue surrounding axons.

What is a cell body? ›

Cell body. Also known as a soma, the cell body is the core section of the neuron. The cell body contains genetic information, maintains the neuron's structure, and provides energy to drive activities. Like other cell bodies, a neuron's soma contains a nucleus and specialized organelles.

What color is the brain? ›

The brain is a pinkish, grayish color, and that's thanks to the parts that compose it. Most of the brain is made of cells called grey matter that are, in fact, gray.

What are the 4 types of brains? ›

Each brain hemisphere (parts of the cerebrum) has four sections, called lobes: frontal, parietal, temporal and occipital. Each lobe controls specific functions.

How big is a human brain? ›

The adult human brain weighs on average about 1.5 kg (3.3 lb). In men the average weight is about 1370 g and in women about 1200 g. The volume is around 1260 cm3 in men and 1130 cm3 in women, although there is substantial individual variation.

Videos

1. What is the Central Nervous System? Facts for Kids
(Hey! Guess What)
2. Central Nervous System (CNS) - MS in a minute
(MS Australia)
3. Anatomy and Physiology I: Central Nervous System (CNS)
(Ross Langston)
4. Lecture11 Central Nervous System
(Physiology for Students)
5. COLLECTION & TRANSPORTATION FOR RESPIRATORY, CENTRAL NERVOUS SYSTEM (CNS) & GASTROINTESTINAL(GIT)
(DR NORMI NGAH MOHAMED)
6. The Nervous System EXPLAINED IN 4 MINUTES - CENTRAL VS PERIPHERAL | SOMATIC VS AUTONOMIC
(5MinuteSchool)
Top Articles
Latest Posts
Article information

Author: Rev. Leonie Wyman

Last Updated: 03/31/2023

Views: 5552

Rating: 4.9 / 5 (59 voted)

Reviews: 90% of readers found this page helpful

Author information

Name: Rev. Leonie Wyman

Birthday: 1993-07-01

Address: Suite 763 6272 Lang Bypass, New Xochitlport, VT 72704-3308

Phone: +22014484519944

Job: Banking Officer

Hobby: Sailing, Gaming, Basketball, Calligraphy, Mycology, Astronomy, Juggling

Introduction: My name is Rev. Leonie Wyman, I am a colorful, tasty, splendid, fair, witty, gorgeous, splendid person who loves writing and wants to share my knowledge and understanding with you.