Question

SOMATIC REFLEXES

Fill in the following chart.

	Stimulus	Receptor	Effector	Normal Response	Circuity (mono vs poly synaptic)
Patellar (Knee-jerk)
Biceps
Triceps
Ankle-Jerk
Withdrawal
Crossed-extensor
Babinski

Answer 1

Patellar jerk

Stimulus : stretch of quadriceps tendon

Receptors: stretch receptor

Effector : quadriceps muscle

response : knee extension

Biceps jerk

Stimulus : stretch of biceps tendon

receptor: stretch receptor in muscle spindle

effector: biceps muscle

response : elbow flexion

Triceps

stimulus : triceps stretch

receptor : stretch receptor in muscle spindle

effector : triceps muscle

response : extension of elbow

Ankle jerk

stimulus : stretch of plantar flexor muscle

receptor: stretch receptor in muscle spindle

effector : plantar flexor

response : plantar flexion of ankle joint

Withdrawal

Stimulus: pin prick

receptor : pain receptors in the finger

effector : flexors muscles of forearm

response: withdrawal of hand by flexion of the forearm

M