Question

The Peripheral Nervous System (PNS) is an “extension” of the CNS. It functions to continue the work that is, at times, started in the CNS. Describe the location and function of the PNS and point out any particular or important information.

Answer 1

PNS or the peripheral nervous system consists of all the nerves and ganglia outside the brain and the spinal cord. It has two components - the somatic nervous system and the autonomic nervous system. There are three types of peripheral nerves - motor, sensory and autonomic.

Sensory nerves- These nerves carry impulses from the sense organs to the brain and the spinal cord. Special sensors in the skin and inside the body help identify heat, cold, smoothness, sharpness etc of the objects one touches. They also help in sensing motion. Any damage to these nerves can cause numbness, pain and tingling sensations.

Motor nerves- These nerves carry impulses from the brain and spinal cord to all the muscles in the body. These nerves help in all types of voluntary movements like walking, jumping, movement of hands, speaking, eating etc. Any damage to the motor nerves can lead to muscle weakness, cramps, spasms, and difficulty in movements.

Autonomic nerves- These nerves control voluntary or semi-voluntary functions like heart rate, blood pressure, sweating, swallowing, urination etc. If the autonomic nerves are damaged the person might feel dizzy when standing, difficulty in swallowing, increased or too slow heart rate, nausea, etc.