They are long nerve processes that may branch out to convey signals to various areas. There are many CNS diseases and conditions, including infections such as encephalitis and poliomyelitis, early-onset neurological disorders including ADHD and autism, late-onset neurodegenerative diseases such as Alzheimer's disease, Parkinson's disease, and essential tremor, autoimmune and inflammatory diseases such as multiple sclerosis and acute disseminated encephalomyelitis, genetic disorders such as Krabbe's disease and Huntington's disease, as well as amyotrophic lateral sclerosis and adrenoleukodystrophy. It includes nuclei linking distinct parts of the motor system, including the cerebellum, the basal ganglia and both cerebral hemispheres, among others. Dendrites typically carry signals toward the cell body. The metencephalon becomes, among other things, the pons and the cerebellum, the myelencephalon forms the medulla oblongata, and their cavities develop into the fourth ventricle.[9]. Spinal cord nerves transmit information from body organs and external stimuli to the brain and send information from the brain to other areas of the body. If in charge of motor function, the area is called the motor cortex. Multiple Sclerosis (MS) Symptoms and Treatment, Central Nervous System (CNS) Parts and Function Topic Guide, Video: 'Tripping on Air,' My Life With MS, Medical Author: Within the central nervous system is a system of hollow cavities called ventricles.

Ascending nerve tracts carry sensory information from the body to the brain. This differentiates the CNS from the PNS, which consists of neurons, axons, and Schwann cells. The ventricles are cerebrospinal fluid-filled cavities in the interior of the cerebral hemispheres. The neural stem cells, principally radial glial cells, multiply and generate neurons through the process of neurogenesis, forming the rudiment of the CNS.[15]. The CNS receives sensory information from the nervous system and controls the body's responses. Fibers that go from the motor cortex to the brainstem (for example, the pons) or the spinal cord receive a name that generally reflects the connections (that is, corticopontine tract for the former and corticospinal tract for the latter). Three membranous coverings, called the meninges, provide mechanical support and protection to the central nervous system. What kind of disease is multiple sclerosis? DAVID MCCARTHY / Science Photo Library / Getty Images. [9], The hippocampus is involved in storage of memories, the amygdala plays a role in perception and communication of emotion, while the basal ganglia play a major role in the coordination of voluntary movement.[9]. The thalamus integrates and relays sensory information to the cortex of the parietal, temporal, and occipital lobes. The cerebrum is the largest part of the brain and controls voluntary actions, speech, senses, thought, and memory. The major trend that can be observed is towards a progressive telencephalisation: the telencephalon of reptiles is only an appendix to the large olfactory bulb, while in mammals it makes up most of the volume of the CNS. The medulla oblongata also helps control involuntary actions, including vital processes, such as heart rate. Some fissures separate lobes. Myelin functions as an electrical insulator that helps axons to conduct nerve impulses more efficiently.

Her work has been featured in "Kaplan AP Biology" and "The Internet for Cellular and Molecular Biologists. During early development of the vertebrate embryo, a longitudinal groove on the neural plate gradually deepens and the ridges on either side of the groove (the neural folds) become elevated, and ultimately meet, transforming the groove into a closed tube called the neural tube.

Neurons are the basic unit of the nervous system. This region of the brain is involved in auditory and visual responses as well as motor function. [8] Oligodendrocytes usually myelinate several axons. Fibers that carry motor input to limbs and fibers that bring sensory information from the limbs to the spinal cord grow together to form a mixed (motor and sensory) peripheral nerve. Its function includes the control of posture and the coordination of movements of parts of the body, including the eyes and head, as well as the limbs.

White matter nerve fiber tracts connect the cerebrum with different areas of the brain and spinal cord. The nerves connect the spinal cord to skin, joints, muscles etc. These nerves send signals between the brain, spinal cord, and other body organs via nerve impulses. Upon CNS injury astrocytes will proliferate, causing gliosis, a form of neuronal scar tissue, lacking in functional neurons. Neurons are classified as either motor, sensory, or interneurons. One of the most important parts of the cerebral hemispheres is the cortex, made up of gray matter covering the surface of the brain. The central structures of the brain include the thalamus, hypothalamus, and pituitary gland. The hindbrain extends from the spinal cord and contains structures such as the pons and cerebellum. Below is a simplified version of these roles: Nerve fibers that exit the brainstem and spinal cord become part of the peripheral nervous system. [6] The brain and spinal cord are both enclosed in the meninges. Neurons contain nerve processes which are "finger-like" projections that extend from the nerve cell body. 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. Sensory neurons send information to the central nervous system from internal organs or external stimuli. That network -- your nervous system -- has two parts: Your brain and spinal cord make up your central nervous system . At this stage, the walls of the neural tube contain proliferating neural stem cells in a region called the ventricular zone. The network of linked cavities in the brain (cerebral ventricles) is continuous with the central canal of the spinal cord. The auditory cortex, localized in the temporal lobe, processes sounds or verbal input.

The right hemisphere controls voluntary limb movements on the left side of the body, and the left hemisphere controls voluntary limb movements on the right side of the body. Like the brain, the spinal cord is covered by the meninges and contains both gray matter and white matter. [9], The cerebrum of cerebral hemispheres make up the largest visual portion of the human brain. These include structures such as the frontal and temporal lobes, the thalamus, the cerebellum, the putamen, mamillary bodies and fornix, and a convolution above the corpus callosum known as the cingulate gyrus. The parietal lobes are located behind the frontal lobes and in front of the occipital lobes. [9] The brain makes up the largest portion of the CNS. The spinal cord relays information up to the brain through spinal tracts through the "final common pathway"[9] to the thalamus and ultimately to the cortex. It is a compact structure in which multiple pathways traverse from the brain to the spinal cord and vice versa. The CNS of chordates differs from that of other animals in being placed dorsally in the body, above the gut and notochord/spine.

Cranial nerves bring information to the CNS to and from the face, as well as to certain muscles (such as the trapezius muscle, which is innervated by accessory nerves[8] as well as certain cervical spinal nerves). Motor neurons carry information from the central nervous system to organs, glands, and muscles. See Additional Information. The hippocampus is located in the temporal lobe but participates in the processing of memory and emotions and is interconnected with central structures. The midbrain is the portion of the brainstem that connects the hindbrain and the forebrain. [9], The brainstem also holds the reticular formation, a group of nuclei involved in both arousal and alertness. The cortex, also called gray matter, is the most external layer of the brain and predominantly contains neuronal bodies (the part of the neurons where the DNA-containing cell nucleus is located). Nerve roots exit the spinal cord to both sides of the body. Almost every person has one dominant hemisphere. Axons of the spinal cord carry signals both away from and toward the brain along descending and ascending tracts. It includes the midbrain, the pons, and the medulla oblongata. Nerve roots are located anterior with relation to the cord if efferent (for example, carrying input toward limbs) or posterior if afferent (for example, to spinal cord). These 12 nerves exist in the head and neck region and are called cranial nerves. Lateral ventricles, Epithalamus, The central nervous system is made up of the brain and spinal cord. [4] A large portion of the brainstem is involved in such autonomic control of the body. home The cerebrospinal fluid circulates around the pia and below the outer arachnoid, and this space is also termed the subarachnoid space. Nuclei in the pons include pontine nuclei which work with the cerebellum and transmit information between the cerebellum and the cerebral cortex. The CNS is so named because it integrates the received information and coordinates and influences the activity of all parts of the bodies of bilaterally symmetric animals—i.e., all multicellular animals except sponges and radially symmetric animals such as jellyfish—and it contains the majority of the nervous system. The cerebrospinal fluid circulates between 2 meningeal layers called the. The brain hemispheres lie on the thalamus. The brain is the major functional unit of the CNS. As a vertebrate grows, these vesicles differentiate further still.