Question

There are how many pairs of cranial nerves in a human?
A.8
B.12
C.25
D.31

Answer 1

The cranial nerve in vertebrates is one of the paired nerves of the peripheral nervous system that directly link the muscles and sensory organs of the head and thoracic region to the brain.

Complete answer:
In higher vertebrates and mammals, there are 12 pairs of cranial nerves. In the human brain, there are 12 pairs of special nerves that are called cranial nerves. The twelve cranial nerves are in order from I to XII: olfactory nerves, optic nerve, oculomotor nerve, trochlear nerve, trigeminal nerve, abducens nerve, facial nerve, vestibulocochlear nerve, glossopharyngeal nerve, vagus nerve, spinal accessory nerve, and hypoglossal nerve.

In higher vertebrates (reptiles, birds, mammals), 12 pairs of cranial nerves are olfactory (CN I), optic (CN II), oculomotor (CN III), trochlear (CN IV), trigeminal (CN V), abductive (CN VI), facial (CN VII), vestibulocochlear (CN VIII), glossopharyngeal (CN IX), vagus (CN X), accessory (CN XI) and hypoglossal (CN XI) (CN XII). There are 10 vertebrate pairs that are inferior to (fish, amphibians). In humans, a 13th pair, a plexus (branching network) known as the terminal nerve (CN 0), is also often recognized, although it is unknown if it is a nerve structure that is vestigial or active.

Hence, the correct answer is option (B)

Note: Motor neurons, sensory neurons, or both form the cranial nerves. They are named for their function or structure; the trigeminal nerve, for example, consists of three primary branches, while the balance and hearing organs are represented by the vestibulocochlear nerve. One of the most important ones is the vagus nerve; it spreads to most of the organs of the chest and upper abdomen.