Question

List the major events that occur in the patellar reflex, from the striking of the patellar ligament to the resulting response by clicking and dragging the labels to the correct location. Then, put these events in their proper sequence from what occurs first at the top. (Some labels may not be used.)

Answer 1

Answer: seen in the explanation.

Explanation:

Patellar reflex is a stretch reflex which tests the Lumber vertebral 2- 4 segments of the spinal cord.

The major event that occurs after Striking of the patellar tendon with a reflex hammer just below the patella includes;

1) It stretches the muscle spindle in the quadriceps muscle.

2) A signal is produced which travels back to the spinal cord and synapses (without interneurons) at the level of Lumber vertebra 3 in the spinal cord, completely independent of higher centres.

3) After the synapse an alpha motor neuron conducts an efferent impulse back to the quadriceps femoris muscle, triggering contraction.

4) Contraction of the quadriceps femoris muscle, coordinated with the relaxation of the antagonistic flexor hamstring muscle causes the leg to kick.

This is a reflex of proprioception which helps maintain balance and posture.