The Nervous System

Question 1

What is the nervous system needed for?

Answer 1

The nervous system uses electrical impulses to bring about fast, but short-lived, responses. It consists of the: brain and spinal cord, which make up the central nervous system (CNS) neurones.

Question 2

What is a receptor for?

Answer 2

Receptors are groups of specialised cells that can detect changes in the environment called stimuli. Receptors are often located in the sense organs, such as the ear, eye and skin. Each organ has receptors sensitive to particular kinds of stimulus.

Question 3

What is a neurone?

Answer 3

A neuron is a nerve cell that is the basic building block of the nervous system. Neurons are similar to other cells in the human body in a number of ways, but there is one key difference between neurons and other cells. Neurons are specialized to transmit information throughout the body.

Question 4

What is the function of each of these neurones?

a. Sensory
b. Relay
c. Motor

Answer 4

a. sensory neurones carry signals from receptors to the spinal cord and brain.
b. relay neurones carry messages from one part of the CNS to another.
c. motor neurones carry signals from the CNS to effectors.