What is Animals Nervous System ?

Animals Nervous System

The nervous system is a system of nervous organs, nerves, and a network of electrically conducting neurons that runs throughout the body of the animal for controlling and coordinating body activities. Body activities are performed in response to internal and external stimuli.

Stimulus is a detectable change in environment, factor, agent or chemical which brings about a response in the organism.

Response is specific reaction of an organism to a specific stimulus.

Receptors are cellular structures that are capable of receiving specific stimuli, generating impulses to be picked up by sensory or afferent nerves.

Impulse is an electrical signal that travels along the length of nerve fibre for passage of information.

Effectors are muscles, glands, cells, tissues or organs which provide the response to a stimulus received through nerve impulse. The message to effectors is sent through motor or efferent nerves.

Sense and Sense Organ. The faculty by which an organism perceives the change in external or internal environment is called sense, e.g., smell, hearing, touch. The organ which contains sensory receptors for obtaining information about the environment is called sense organ, e.g., eye, ear.

In humans and higher animals there is brain which functions as a super centre for control and coordination of various activities. The basic unit of nervous system is neuron or nerve cell.