Question

The difference between cranial and spinal nerves is
a. Spinal nerves comprise sensory and motor fibres and cranial nerve has only one kind
b. Spinal sensory nerves form dorsal root ganglia at their origin from spinal cord and cranial nerves originate from brain
c. Both of the above
d. None of the above

Answer 1

Hint: Cranial nerves are those that emerge directly from the brain. Spinal nerves are those that emerge directly from segments of the spinal cord. Cranial nerve transfers information between the brain and the other parts of the body.

Complete answer:
Cranial nerves are those that emerge directly from the brain. Spinal nerves are those that emerge directly from segments of the spinal cord. Cranial nerve transfers information between the brain and the other parts of the body.

Cranial nerves arise from the brain. They may be sensory, motor or both. There are 12 pairs in total. They can be branched or unbranched. These are not formed from ventral or dorsal roots like that of the spinal nerve.
On exiting they come out of the foramina of the skull.

Spinal nerves are those that directly arise from the segments of spinal cord. First is an exception as it arises directly from medulla oblongata. They are mixed in nature. There are 31 pairs in total. These are always branched. Each nerve gives 3 branches further. These are formed by the ventral and dorsal roots. These emerge out from intervertebral foramina.

Hence second option B is true i.e spinal sensory nerves from dorsal root ganglia at their origin from spinal cord and cranial nerves originate from brain.

Note: Cranial nerves arise from the brain. They may be sensory, motor or both. There are 12 pairs in total. They come out of the foramina of the skull. Spinal nerves are those that directly arise from the segments of spinal cord. First is an exception as it arises directly from medulla oblongata. They are mixed in nature. There are 31 pairs in total. These emerge out from intervertebral foramina.