Central Nervous System

Brain

The brain is responsible for co-ordinating, integrating and controlling the rest of the nervous system. The brain is divided into several parts. Based on phylogenetic development, it can be divided into the forebrain, midbrain and hindbrain. Based on gross anatomy, it can be divided into the cerebrum, cerebellum and brainstem. The brain is enclosed within the cranial cavity of the skull.

Forebrain

Thalamus
Hypothalamus
Pituitary
Cerebral Cortex
Limbic System
Olfactory Bulb

Midbrain

Hindbrain

Cranial Nerves

Cranial nerves arise from the brain and brain stem, rather than the spinal cord. Nerves arising from the spinal cord are the peripheral nerves. There are 12 pairs of cranial nerves and these pairs of nerves passage through foramina in the skull, either individually or in groups. Cranial nerves are traditionally referred to by Roman numerals and these numerals begin cranially and run caudally.

Olfactory Nerve (I)

Optic Nerve (II)

Oculomotor nerve (III)

Trochlear nerve (IV

Trigeminal nerve (V)

Opthalmic nerve (V1)

Maxillary nerve (V2

Mandibular nerve (V3

Abducent nerve (VI)

Facial nerve (VII)

Vestibulocochlear nerve (VIII)

Glossopharyngeal nerve (IX)

Vagus nerve (X)

Accessory nerve (XI)

Hypoglossal nerve (XII)

Spinal Cord

Meninges

Cerebrospinal Fluid

Peripheral Nervous System