Question

Which of the following cranial nerves is not a motor nerve?
A) II
B) III
C) IV
D) XII

Answer 1

Hint:There are 12 pairs of cranial nerves in our body which arise from the brain. These nerves connect the brain to different body parts like head, neck and trunk. The cranial nerves can be sensory, motor or mixed nerves.

Complete answer:
To answer this question, we must know about the types of cranial nerves.
The cranial nerves are of three types-
1) Sensory-The sensory nerves deal with the transmission of impulses related to 5 senses i.e. see, taste, touch, feel and hear.
2) Motor-The motor nerves deal with the transmission of impulses related to movement.
3) Mixed-The mixed nerves have both sensory and motor function.

Let us discuss the given options.
A) II- It is called optic nerve which transmits impulses related to vision. It is a sensory nerve.
B) III- It is called the oculomotor nerve. It is responsible for eye muscle and pupil movement. It is a motor nerve.
C)IV- It is called the trochlear nerve. It is related to the eye. It is a mixed nerve having both sensory and motor function.
D) XII- It is a hypoglossal nerve which controls the movement of muscles in the tongue. It is a motor nerve.

Thus the correct answer is option ‘B’(II). Optic nerve is not a motor nerve.

Note:The cranial nerves are 12 pairs in number and are named in roman number from I to XII. They are named according to their function. The numbering is done in terms of location from front to back.