Co-ordination & Response Practice Questions

Which letter labels the axon?

Put a cross ( ☒ ) in the box next to your answer.

☐ A

☐ B

☐ C

☐ D

Name the structure labelled A.

..............................................................

Explain how the myelin sheath helps the motor neurone to carry out its function.

Which structures make up the central nervous system (CNS)?

Put a cross ( ☒ ) in the box next to your answer.

☐ A the brain and the spinal cord

☐ B the brain and the sense organs

☐ C the spinal cord and the motor neurones

☐ D the sense organs and the nerves

Name the effector that produces the response in this example.

..............................................................

Describe the role of the sensory neurone in this response.

Which statement describes a synapse?

Put a cross ( ☒ ) in the box next to your answer.

☐ A the fatty covering around an axon

☐ B a gap between two neurones

☐ C a receptor cell found in the skin

☐ D the part of a neurone containing the nucleus

Name the type of chemical that is released into a synapse.

..............................................................

When a person hears a loud bang, an electrical impulse travels along a sensory neurone and reaches a synapse with a relay neurone in the central nervous system.

Explain how the signal is passed from the sensory neurone to the relay neurone at this synapse.

Calculate the time taken for an impulse to travel the length of this motor neurone.

Give your answer in milliseconds (ms).

.............................................................. ms

If this neurone had no myelin sheath, impulses would travel at only $0.5$ m/s.

Calculate how many times longer the impulse would take to travel the length of the neurone without a myelin sheath.

.............................................................. times longer

The table gives some information about three types of neurone.

Complete the table by writing an answer in each of the boxes (i), (ii) and (iii).

feature	sensory neurone	relay neurone	motor neurone
receives impulses from	receptor	sensory neurone	(i)
long dendron present	yes	no	no
transmits impulses to	(ii)	motor neurone	(iii)

Calculate the mean increase in reaction time caused by the background noise.

Give your answer in milliseconds (ms).

.............................................................. ms

Pressing the key when the shape appears is not a reflex action.

Explain why.

Before filling a tooth, a dentist injects a local anaesthetic into the gum. The anaesthetic molecules prevent neurotransmitters from binding to the receptors on the next neurone.

Explain why the patient does not feel pain while the tooth is being filled.

A person accidentally places a hand on a very hot oven tray. Without thinking, they immediately pull their hand away.

Explain how the nervous system produces this response, from the stimulus to the response, and why this type of response is useful to the body.

Calculate the percentage increase in the mean response time for the person with MS.

.............................................................. %

Explain why damage to the myelin sheath increases the response time.

An electrical impulse can travel along the axon of a myelinated neurone at up to $100$ m/s, but it takes about $0.5$ ms to cross a single synapse. An impulse can only cross a synapse in one direction.

Explain why transmission across a synapse is slower than transmission along an axon, and why it can only happen in one direction.