BY4 - Co-ordination

Question 0

The nervous system is divided into two main parts. State their names

Answer 0

The central nervous system (CNS)

The peripheral nervous system

Question 1

What does the nervous system carry out?

Answer 1

Detects change or stimuli inside the body and from the environment
Processes information
Initiates responses

Question 2

Define the term reflex arc

Answer 2

A rapid, involuntary response resulting from nervous impulses initiated by a stimulus. It does not involve the brain

Question 3

Why is a reflex arc important?

Answer 3

Because it (generally) provides protection.

Question 4

Briefly describe the reflex arc

Answer 4

A stimulus
Receptor
Sensory neurone sends impulse to spinal cord
Relay neurone sends an impulse to the effector
Response

Question 5

Why do Hydra have slow nerve impulse transmission? Why is it important?

Answer 5

Hydra have nerve nets that have short extensions and branch out in different directions.
Enables the Hydra to sense its surroundings an respond to stimuli appropriately. Response for attacking prey and avoiding danger from predators by retracting the body

Question 6

Give the three types of neurones

Answer 6

Sensory
Motor
Relay

Question 7

Where does the sensory neurone enter the spinal cord? Where is its cell body?

Answer 7

The dorsal root. In dorsal root ganglion

Question 8

Where does the motor neurone leave the spinal cord? Where is its cell body located?

Answer 8

Ventral root. In the grey matter.

Question 9

Define the term resting potential

Answer 9

The potential difference between the inside and the outside of the membrane when a nerve impulse is not being conducted

Question 10

Define the term action potential

Answer 10

A change that occurs in the electrical charge cross the membrane of an axon when it is stimulated and a nerve impulse passes

Question 11

Define the term depolarisation

Answer 11

A temporary reversal of charge on the membrane of a neurone that takes place when a nerve impulse is transmitted