Table of ContentsView AllTable of ContentsCNS StructuresCNS DiseasesFAQ
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CNS Structures
CNS Diseases
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Thecentral 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 theperipheral 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
Thebraincontrols 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:
Other important areas of the brain include the basal ganglia, cerebellum, Broca’s area, corpus callosum, medulla oblongata, hypothalamus, thalamus, and amygdala.
RecapThe brain is the part of the central nervous system that controls many of the functions of the body, including movement, thought, learning, and awareness.
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.
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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:
RecapThe spinal cord carries information from the brain to the rest of the body and transmits signals from the body to the brain.
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.
Neurons are the body’s information superhighway. An estimated86 billion neurons can be found in the brain alone.
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.
RecapNeurons are the cells that make up the central nervous system. They are responsible for communicating information throughout the body.
Neurons are the cells that make up the central nervous system. They are responsible for communicating information throughout the body.
Protective Structures
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:
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.
Diseases of the Central Nervous System
There are a number ofproblems 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:
RecapA 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.
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.
What Is Central Nervous System (CNS) Depression?
Frequently Asked Questions
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.
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.
8 SourcesVerywell Mind uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read oureditorial processto learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.American Association of Neurological Surgeons.Anatomy of the brain.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.0071275American Association of Neurological Surgeons.Anatomy of the spine and peripheral nervous system.Herculano-Houzel S.The human brain in numbers: a linearly scaled-up primate brain.Front Hum Neurosci. 2009;3:31. doi:10.3389/neuro.09.031.2009Kayalioglu G.The vertebral column and spinal meninges. In:The Spinal Cord. Elsevier; 2009:17-36. doi:10.1016/B978-0-12-374247-6.50007-9Moini J, Piran P.Meninges and ventricles. In:Functional and Clinical Neuroanatomy. Elsevier; 2020:95-129. doi:10.1016/B978-0-12-817424-1.00004-5Nagappan 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/s40779-020-00259-3Cleveland Clinic.Paralysis.
8 Sources
Verywell Mind uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read oureditorial processto learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.American Association of Neurological Surgeons.Anatomy of the brain.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.0071275American Association of Neurological Surgeons.Anatomy of the spine and peripheral nervous system.Herculano-Houzel S.The human brain in numbers: a linearly scaled-up primate brain.Front Hum Neurosci. 2009;3:31. doi:10.3389/neuro.09.031.2009Kayalioglu G.The vertebral column and spinal meninges. In:The Spinal Cord. Elsevier; 2009:17-36. doi:10.1016/B978-0-12-374247-6.50007-9Moini J, Piran P.Meninges and ventricles. In:Functional and Clinical Neuroanatomy. Elsevier; 2020:95-129. doi:10.1016/B978-0-12-817424-1.00004-5Nagappan 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/s40779-020-00259-3Cleveland Clinic.Paralysis.
Verywell Mind uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read oureditorial processto learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
American Association of Neurological Surgeons.Anatomy of the brain.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.0071275American Association of Neurological Surgeons.Anatomy of the spine and peripheral nervous system.Herculano-Houzel S.The human brain in numbers: a linearly scaled-up primate brain.Front Hum Neurosci. 2009;3:31. doi:10.3389/neuro.09.031.2009Kayalioglu G.The vertebral column and spinal meninges. In:The Spinal Cord. Elsevier; 2009:17-36. doi:10.1016/B978-0-12-374247-6.50007-9Moini J, Piran P.Meninges and ventricles. In:Functional and Clinical Neuroanatomy. Elsevier; 2020:95-129. doi:10.1016/B978-0-12-817424-1.00004-5Nagappan 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/s40779-020-00259-3Cleveland Clinic.Paralysis.
American Association of Neurological Surgeons.Anatomy of the brain.
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
American Association of Neurological Surgeons.Anatomy of the spine and peripheral nervous system.
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
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
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
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
Cleveland Clinic.Paralysis.
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