reflexes

Question 1

1. What is the role of a receptor?

Answer 1

To detect a stimulus (change in the environment)

Question 2

2. What is the role of the sensory neurone?

Answer 2

Transmit electrical impulses from receptors to the CNS

Question 3

3. What is the role of the relay neurone (intermediate neurone)?

Answer 3

Transmit electrical impulses between sensory neurones and motor neurones. In some reflex actions there is only 1 relay neurone

Question 4

4. What is the role of the motor neurone?

Answer 4

Transmit electrical impulses from the CNS to the effector

Question 5

5. Describe the pathway of nervous communication in a voluntary response.

Answer 5

Receptor detects a stimulus, sensory neurones transmit electrical impulses from receptors to the CNS. The CNS processes the information and sends impulses along motor neurones to effectors which respond

Question 6

6. Explain why nervous communication leads to a localised and short-lived response.

Answer 6

Neurotransmitters are secreted directly onto the next cell. The response is shorted lived as neurotransmitters are removed quickly.

Question 7

7. Explain why reflexes are involuntary

Answer 7

The pathway of communication goes through the spinal cord, not the conscious part of the brain

Question 8

8. What are the advantages of reflexes?

Answer 8

As they are very rapid, do not have to be learnt, protect against damage, enable homeostatic control

Question 9

9. What is an effector?

Answer 9

Cells that bring about a response to a stimulus, such as muscle cells or gland cells

Question 10

10. What is a response?

Answer 10

The muscle cells contracting causing movement, or glands secreting a hormone

Question 11

11. What is the purpose of reflexes?

Answer 11

They bring about responses that maintain posture and protect against harmful stimuli