Question

The number of spinal nerves in humans is
(a)10 pairs
(b)12 pairs
(c)43 pairs
(d)31 pairs

Answer 1

Hint: The spinal nerves arise from the spinal cord. These are present in the neck region, thoracic region, the upper part of the abdomen, the lower part of the abdomen, and the coccyx.

Complete answer:
There are 31 pairs of spinal nerves present in humans. These spinal nerves are divided into five groups, which are:
Cervical spinal nerves: These are 8 pairs, i.e. 16 in number. These are present in the neck region of the body.
Thoracic spinal nerves: These are 12 in pairs, i.e. 24 in number. These are present from the base of the neck up to the abdomen.
Lumbar spinal nerves: These are 5 in pairs, i.e. 10 in number. These are present in the upper part of the abdomen.
 Sacral spinal nerves: These are 5 in pairs, i.e. 10 in number. These are present in the lower part of the abdomen.
 Coccygeal spinal nerves: These are 1 in pair, i.e. 2 in number. These are present in the coccyx part of the body.

Additional Information:
 -The nerve that carries signals from the brain or spinal cord to the muscles and glands are known as motor nerves.
-Sensory nerves carry signals from the muscles and sensory organs towards the central nervous system.

So, the correct answer is, ’31 pairs.’

Note: The spinal cord extends between the spinal cord and the body parts and is mixed in nature. Mixed nerves have both sensory and motor nerve fibers and can conduct signals in both directions at the same time.