5.1.5 reflexes

Question 1

what is the pathway for reflex action?

Answer 1

receptor
sensory neurone
relay neurone
motor neurone
effector

Question 2

what is the spinal cord?

Answer 2

a column of nervous tissues running up the back

Question 3

what emerges at intervals along the spinal cord?

Answer 3

pairs of neurones

Question 4

what happens when the leg is tapped just below the kneecap?

Answer 4

stretches the patellar tendon and acts as a stimulus

Question 5

what does the stimulus in the knee jerk reaction initiate?

Answer 5

a reflex arc that causes the extensor muscle on top of the thigh to contract

Question 6

what happens at the same time the extensor muscle contracts?

Answer 6

a relay neurone inhibits the motor neurone of the flexor muscle causing it to relax

Question 7

what causes the leg to kick?

Answer 7

contraction coordinated with the relaxation

Question 8

what does the absence of the knee-jerk reflex indicate?

Answer 8

nervous problems

Question 9

why are reflexes essential for survival?

Answer 9

they avoid the body being harmed or reduce the severity of any damage

Question 10

how do reflexes increase your chance of survival?

Answer 10

they are involuntary responses
they don’t have to be learnt
extremely fast
many reflexes are what we would consider everyday actions