Somatic nervous system facts for kids
The somatic nervous system (SNS), or voluntary nervous system is the part of the peripheral nervous system. It is associated with the voluntary control of body movements via skeletal muscles.
The somatic nervous system consists of sensory nerves carrying afferent nerve fibers, which relay sensation from the body to the central nervous system (CNS), and motor nerves carrying efferent nerve fibers, which relay motor commands from the CNS to stimulate muscle contraction.
There are 43 segments of nerves in the human body. With each segment, there is a pair of sensory and motor nerves. In the body, 31 segments of nerves are in the spinal cord and 12 are in the brain stem. Besides these, thousands of association nerves are also present in the body.
Thus the somatic nervous system consists of two parts:
- Spinal nerves: They are mixed nerves that carry sensory information into and motor commands out of the spinal cord.
- Cranial nerves: They are the nerve fibers that carry information into and out of the brain stem. They include smell, vision, eye, eye muscles, mouth, taste, ear, neck, shoulders, and tongue.
The somatic nervous system controls all voluntary muscular systems within the body, and the process of voluntary reflex arcs.
See also
In Spanish: Sistema nervioso somático para niños
