A2 essentials

Brainstem

Consists of the midbrain, pons, and medulla.

Cerebellum

Located posterior to the pons.

Cerebrum

The largest part of the brain.

Central sulcus

Divides the frontal lobe and parietal lobe.

Grey matter

Contains cell bodies of neurons.

White matter

Composed of myelinated axons.

Cranial nerves

There are 12 pairs of cranial nerves.

CN 1 I (Olfactory)

Responsible for the sense of smell.

CN 2 II (Optic)

Responsible for vision.

CN 3 III (Oculomotor)

Controls eye movement.

CN 4 IV (Trochlear)

Also responsible for eye movement.

CN 5 V (Trigeminal)

Involved in chewing (mastication) and facial sensation.

CN 6 VI (Abducens)

Controls eye movement.

CN 7 VII (Facial)

Responsible for facial expression; damage can cause Bell’s palsy.

CN 8 VIII (Vestibulocochlear)

Responsible for hearing and balance.

CN 9 IX (Glossopharyngeal)

Involved in swallowing and gag reflex.

CN 10 X (Vagus)

Controls organs in the thorax and abdomen.

CN 11 XI (Accessory)

Involved in shoulder shrug.

CN 12 XII (Hypoglossal)

Controls tongue movement.