The cranial nerves

 Organ system: Peripheral nervous system

Features

• There are 12 well-known cranial nerves and 1 disputed cranial nerve (CN-0).
• The cranial nerves exist in symmetrical pairs.
• CN-0, CN-I, CN-II arise from the brain.
• CN-III to CN-XII (ten cranial nerves) arise from the brainstem.
• CN-II is not a peripheral nerve in the strictest sense, but it is technically a component of the CNS. This is because it is a rather a tract which outpouches from the diencephalon during embryonic development.

• CN 0 – Terminal
• CN I – Olfactory
• CN II – Optic
• CN III – Oculomotor
• CN IV – Trochlear
• CN V – Trigeminal
• CN VI – Abducens
• CN VII – Facial
• CN VIII – Vestibulocochlear
• CN IX – Glossopharyngeal
• CN X – Vagus
• CN XI – Accessory
• CN XII – Hypoglossal

Pathology

• Cranial nerve diseases

 

Compare with

• Spinal nerves