THE PERIPHERAL NERVOUS SYSTEM (PNS)

CONTENT

1. The Peripheral Nervous System
2. Structure and Functions of a Neuron
3. Reflex and Voluntary Actions

The Peripheral Nervous System (PNS)

Definition of Peripheral Nervous System (PNS)

The peripheral nervous system links the CNS with the body’s receptors and effectors in mammals. When receptors pick up impulses of change in the environment, messages are sent to the CNS which integrates the information and sends appropriate messages to the effectors accordingly.

Types of Peripheral Nerves

The peripheral nerves are of two types, namely;

(i) the spinal nerves connected to the spinal cord and

(ii) the cranial nerves, connected to the brain.

The spinal nerves serve the receptors and effectors in the other body parts.

The cranial nerves are associated chiefly with the receptors and effectors in the head, while

Components of the Peripheral Nervous System (PNS)

The PNS consists of

(i) The Somatic nervous system (SNS) and

(ii) The Autonomic nervous system (ANS).

(i) Somatic Nervous System

The nerves of the SNS principally serve the parts of the body which take part in responses to external stimuli (e.g.