The Nervous System

Question 1

The purpose of the nervous system is …

Answer 1

… to communicate between cells via electrical impulses and to react to stimuli in the environment.

Question 2

Sensory ___s are groups of cells that detect ___ and ___ responses to them.

Answer 2

receptor, stimuli, initiate

Question 3

In mammals, the CNS is connected to the body by ___ (body > CNS) and ___ (CNS > body) neurones. Information is transmitted as ___ ___.

Answer 3

sensory, motor, electrical, impulses

Question 4

The CNS (___) is where information from ___ receptors is sent, and where ___ and ___ are coordinated.

Answer 4

Central Nervous System, sensory, reflexes, actions

Question 5

Effectors can be ___ (which contract) or ___ (which secrete ___) and are where ___ is sent to from the CNS to which they respond.

Answer 5

muscles, glands, hormones, information

Question 6

The connection between two neurones is called a ___. Nerve signals are diffused across this gap as chemicals called ___. This ___ transmission of nervous impulse.

Answer 6

synapse, neurotransmitters, slows

Question 7

Reflexes are ___ and ___ responses to specific stimuli. They completely bypass the conscious ___, travelling along a reflex ___.

Answer 7

fast, automatic, brain, arc

Question 8

Main stages of a reflex arc:

Answer 8

1. When a stimulus is detected by receptors, impulses are sent along a sensory neurone to a relay neurone in the CNS.
2. The impulse crosses the synapse to be sent along the relay neurone.
3. The impulse travels the relay neurone then crosses the synapse to be sent along the motor neurone.
4. The impulse then travels the motor neurone to the effector, which responds.