Knee-jerk reflex

Question 1

What type of reflex is the knee-jerk reflex?

Answer 1

Spinal reflex

Question 2

Outline the knee-jerk reflex

What disease is associated with faults in the knee jerk reflex?

Answer 2

1) The leg is tapped underneath the kneecap which stretches the patellar tendon and acts as a stimulus
2) The stimulus causes the extensor muscle on top of the thigh to contract whilst a relay neurone inhibits the motor neurone of the flexor muscle, causing it to relax.

Absence of the reflex indicates a cerebral disease