Nervous system, synapses and reflexes

Question 1

What is a Nervous system?

Answer 1

Multicellular organisms need a way for cells to communicate with one another. This has led to the development of nervous communication systems.

The nervous system uses electrical impulses to bring about fast, but short-lived, responses.

Question 2

What is this?

Answer 2

A neurone

Question 3

What is a receptor?

Answer 3

Receptors are groups of specialised cells. They can detect changes in the environment, called stimuli, and turn them into electrical impulses. Receptors are often located in the sense organs such as the ear, eye and skin.

Question 4

What is an effector?

Answer 4

Effectors are parts of the body that produce a response. Here are three examples:

a muscle contracting to move an arm

a muscle squeezing saliva from the salivary gland

a gland releasing a hormone into the blood