Question

The cranial nerves which originate from the medulla oblongata
(a) IX, X, XI, and XII
(b) III, VII, and IX
(c) VII, VIII, and X
(d) VIII, IX, XI and XII

Answer 1

Cranial nerves are the nerves that originate directly from the brain. It is a set of 12 nerves. Each nerve has a name that reflects its function and location in the brain. The numbering is based on order in which they emerge from the brain, from front to back. Most of the lower cranial nerves originate from medulla.

Complete answer:
The cranial nerves emerge from the central nervous system. It relays information between the brain and different body parts. They are 12 in pairs. Each cranial nerve is paired and is present in both sides. They are described with Roman numerals I-XII. The terminal nerves (0) , olfactory nerves (I) and optic nerves (II) , emerge from the cerebrum, and the remaining pairs arise from brainstem, which is the lower part of the brain. Medulla oblongata together with pons and midbrain forms the brain stem. The medulla oblongata contains a number of important afferent and efferent tracts of nerves.
So, the correct answer is ‘VIII, IX, XI and XII’.

Additional information:
- The oculomotor nerve emerges from the midbrain- pontine junction. The trochlear nerve (IV) emerges from the posterior side of the midbrain.
- Trigeminal nerve (V) emerges from pons. The abducens, facial and vestibulocochlear (VI-VIII) emerges from the pontine-medulla junction.
- Cranial nerves are considered components of peripheral nervous systems, although on structural level optic, olfactory and trigeminal nerves are part of the central nervous system.

Note:
- Cranial nerves differ from spinal nerves especially in their development and their relation to special senses.
- Fibers in cranial nerves are of diverse functional types. Some cranial nerves are composed of only one type, others of several.
- Cranial nerves act as either one way or a two way road, meaning that some of them transmit information only to the brain, others only transmit instructions out, while others receive and transmit information.