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Central Nervous System

 

The Central Nervous System (CNS) is the collective name for the brain and the spinal cord. It contrasts with the Peripheral Nervous System which passes nerve signals between the CNS and rest of the body.

The CNS contains billions of nerve cells called neurons, which do all the processing and communication, and trillions of suport cells, called glial cells, which assist its functioning, repair damage and isolate it from the rest of the body. There are two different types of region in the CNS called grey matter and white matter. Grey matter is where all the processing is done and white matter is responsible for communicating between regions of grey matter and between the grey matter and the reset of the body.

In multiple sclerosis (MS), neurons get stripped of their insulating material (myelin) in patches of damage called lesions or plaques. These lesions predominantly affect the white matter (about 95%) but a few lesions are found in grey matter (about 5%).
 
Central Nervous System areas and % frequency of MS lesions over whole course of disease
Anatomical CNS Site Function % frequency of MS lesions
Cerebral Cortex Memory, perceptual awareness, "thinking", language and consciousness
22.0
Subcortical White Matter  Communication between CNS areas
45.8
Central White Matter Communication between CNS areas
86.3
Frontal Lobe Reasoning, planning, parts of speech and movement (motor cortex), emotions, and problem-solving.
45.8
Parietal Lobe Perception of stimuli related to touch, pressure, temperature and pain.
35.7
Occipital Lobe Vision.
10.1
Periventricular The areas close to the ventricles
    IIIrd Communication between CNS areas
11.1
    IVth Communication between CNS areas 53.8
    Lateral Communication between CNS areas
77.7
Corpus Callosum Connects the right and left hemispheres of the brain
55.6
Hippocampus Memory
21.6
Caudate Nucleus Processing of somatosensory, auditory and visual information
9.5
Thalamus Processing of olfactory (taste and smell) information
15.9
Putamen Processing of somatosensory, auditory and visual information
9.5
Globus Pallidus Coordinating movement
12.7
Internal Capsule   
25.4
Fornix Fibre tract that connects the parts of the brain involved emotional and other behaviours
4.9
Hypothalamus Brain structure that monitors internal body environment and attempts to maintain balance of these systems. Controls the pituitary gland.
6.5
Insula/Claustrum   
15.4
Tectum   
47.1
Tegmentum   
47.1
Periaqueductal   
55.9
MidBrain Nerve pathway of cerebral hemispheres. Coordination, Auditory and Visual reflex centres. Cranial nerves III and IV.
    Red Nucleus "
29.4
    Substantia Nigra "
29.4
    Basis Pedunculi "
35.3
Pons Respiratory centre, cranial nerves V, VI, VII and VIII.
    Tegmentum "
53.8
    Decussation "
53.8
Medulla Crossing of motor tracts. Cardiac and respiratory centres, control of the blood vessel walls, centres for cough, gag, swallow, and vomit. Cranial Nerves IX, X, XI and XII.
    Dorsal "
30.4
    Reticular "
35.9
    Olives "
23.9
    Pyramids "
13.0
Cerebellum Coordination and control of voluntary movement. 
    Brachium Pontis " 48.1
    Inferior Cerebellar 
    Peduncle
" 34.5
    Cortex "
1.0
    Dentate Nucleus "
2.0
    Digital White Matter "
7.8
    Central White Matter "
30.4
Optic Nerve Transmission of visual information from the eye to the brain
55.0
Optic Chiasm The area where visual information crosses to the opposite hemisphere
35.0
Spinal Cord Transmission of information between the central nervous system and the body
    Lateral Column "
50.8
    Ventral Column "
18.5
    Grey Matter "
3.4
Cord Thoracic, post, column "
    Lateral Column "
27.1
    Ventral Column "
10.2
    Grey Matter "
3.4
Cord Lumbar, post, column "
    Lateral Column "
8.5
    Ventral Column "
8.5
    Grey Matter "
1.7

Central Nervous System Links:
Brain Facts and Figures
Neuroscience for Kids


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