13.8 Reflexes

Question 1

Why do we have reflexes?

Answer 1

To prevent / minimise damage to the body

Question 2

Define reflex action

Answer 2

Involuntary response to a sensory stimulus

Question 3

What is the reflex arc?

Answer 3

Pathway of neurones involved in reflex action

Question 4

What are the 4 phases of the reflex arc?

Answer 4

1. Receptor - detects stimulus and creates AP in sensory neurone
2. Sensory neurone - carries impulse to spinal cord
3. Relay neurone - connects sensory neurone to motor neurone within the spinal cord or brain
4. Motor neurone - carries impulse to effector to carry out the appropriate response

Question 5

What is the spinal cord?

Answer 5

A column of nervous tissues running up the back, surrounded by the spine for protection.
At intervals along the spinal cord, pairs of neurones emerge