Question

Purely motor nerve is
A)Optic
B)Abducens
C)Ophthalmic
D)Palatinus

Answer 1

Hint: The motor nerve can be identified as a nerve which is located in the central nervous system (CNS), usually in the spinal cord, which is responsible for transmitting a motor signal from the CNS to parts of the body. It is different from the motor neuron that has the cell body, the dendrite branching, on the other hand the nerve is made up of axons in the bundle.

Complete answer:
A. The optic nerve is CN II. The optic nerve is the visual nerve responsible for the sense of vision from the retina.
B. Abducens is a CN VI that innervates the lateral rectus muscle of the eyes and is responsible for eyeball movement. It is a motor nerve, which originates from the pons of the brain.
C. The ophthalmic nerve is a sensory branch of the trigeminal nerve, which is a mixed nerve.
D. Palatinus or torus palatinus is a harmless, painless development of the bones on the roof of the mouth (the hard palate). The mass occurs in the center of the hard palate and can differ in size and form.

There are four cranial nerves of mainly motor activity. CN IV, Trochlear, innervates the upper oblique muscle of the eyeball. CN VI, Abducens, innervates the lateral rectus muscle of the eyeball and abducts the eye.

Hence, the correct answer is option (B)

Note: In all there are twelve cranial nerves. The olfactory nerve (CN I) and the optic nerve (CN II) derive from the brain. Cranial nerves III – XII originate from the stem of the brain. They can originate from a particular part of the brain stem (midbrain, pons or medulla).