Chapter 13: The Nervous System

Question 1

Define what a stimulus is

Answer 1

A stimulus is any change in the environment which that an organism to react

Question 2

Define what a response is

Answer 2

A response the organism’s reaction to a stimulus

Question 3

Define sensitivity

Answer 3

The ability of an organism to detect and respond to changes in the environment

Question 4

What are involuntary actions?

Answer 4

Actions that are not controlled consciously

Question 5

What are the 2 human nervous systems?

Answer 5

The central nervous system and the peripheral nervous system

Question 6

Define receptors

Answer 6

Sense organs that receive stimuli

Question 7

State the parts of a neurone and its functions/characteristics

Answer 7

Cell body, axon, and dendron

Cell body - Contains cell membrane. cytoplasm, nucleus and organelles. It is where chemical reactions occur to release energy(respiration) for the cell to survive and carry out activities.

Dendron - Nerve fibres that end in finder nerve fibres called dendrites. Dendrons transmit nerve impulses towards the cell body.

Axon - Nerve fibres that transmit nerve impulses. The Axon transmits nerve impulses away from the cell body.

Question 8

State the reflex arc

Answer 8

Recepter -> sensory neurone -> relay neurone -> Motor neurone -> effector

Question 9

What are features of the sensory neurone

Answer 9

1. The cell body is on the side
2. Myelin sheath present
3. Transmits nerve impulses from the receptors central nervous system

Question 10

What are features of the relay neurone

Answer 10

1. Cell body present
2. No myelin sheath
3. Transmits nerve impulses from the sensory neurone to the motor neurone

Question 11

What are features of the m motor neurone

Answer 11

1. Cell body is at one end
2. Myelin sheath present
3. Transmits nerve impulses from central nervous system to the effector(s)