Nervous System Overview

The spinal cord is supplied by spinal and radicular arteries, and drained by vertebral plexuses of veins.

Clear fluid in the CNS cavities, including brain ventricles, sub-arachnoid space, and spinal cord central canal.

12 pairs of nerves connected to the brain, mostly from the brainstem; olfactory and optic nerves are exceptions.

The first cranial nerve (I); a pure sensory nerve for smell, capable of regeneration after injury.

The second cranial nerve (II); a pure sensory nerve for vision that does not regenerate after injury.

The third cranial nerve (III); motor nerve for eye muscles excluding superior oblique and lateral rectus.

The fourth cranial nerve (IV); motor nerve for the superior oblique muscle of the eye.

The fifth cranial nerve; a mixed nerve providing sensation to the face and supplying muscles of mastication.

A pure motor nerve supplying trapezius and sternomastoid muscles.

The motor nerve of the tongue; injury causes tongue deviation to affected side.

There are 31 pairs of spinal nerves, divided into cervical, thoracic, lumbar, sacral, and coccygeal regions.

Each spinal nerve (except C1 and coccygeal) arises from ventral and dorsal roots.

Nerve trunk divides into anterior (ventral) and posterior (dorsal) rami, with connections to sympathetic ganglia.

Cranial nerve VII; a mixed nerve for taste and facial expression.

Cranial nerve VIII; transmits sound and balance information from the inner ear.

Cranial nerve IX; mixed nerve with taste, sensory, and motor functions for swallowing.

Cranial nerve X; a mixed nerve influencing heart rate and GI functions.

Condition resulting from injury to the facial nerve, leading to facial paralysis.

Involuntary eye movement often associated with vestibulo-cochlear nerve damage.

Severe pain caused by irritation of the glossopharyngeal nerve.

Sensory receptors in carotid and aortic bodies adjusting blood pressure and pH.