3.8 The Nervous System

Question 1

What are the two main divisions of the nervous system

Answer 1

Central nervous system
Peripheral nervous system

Question 2

Whats part of the CNS

Answer 2

Brain and spinal chord

Question 3

Whats part of the peripheral nervous system

Answer 3

Composed of spinal nerves, cranial nerves and their roots and branches.

Question 4

Define a stimuli

Answer 4

Changes in external and internal environments

Question 5

Define a receptor

Answer 5

Receptor cells detect stimuli
They’re often part of receptor organs such as ears, eyes or skin
They have special receptor proteins that do the sensing

Question 6

Define a coordinator

Answer 6

Name given to the network of relay neurones connecting sensory and motor systems
It’s job is to receive impulses from sensory neurones and transmits impulses to motor neurones

Question 7

Define effector

Answer 7

Cells that effect a response
In humans, there are muscles and glands

Question 8

Define response

Answer 8

Response aids survival
They include movements of all kinds and secretions from glands and all behaviours

Question 9

Describe the reflex arc

Answer 9

A receptor detects the stimulus (examples are usually heat or pressure from a pin).

A nerve impulse is initiated and transmitted via a sensory neurone into the spinal cord.

The impulse crosses a synapse into a relay neurone in the grey matter.

The impulse is transmitted through the relay neurone to a motor neurone across a synapse.

The motor neurone transmits the impulse to an effector.

The effector makes the response (examples would be the biceps muscle as an effector, contracting to move the hand away from a hot or sharp object).