When a person is standing with their elbow bent, and someone grabs their arm and yanks, the biceps will contract and the triceps relax in order to produce a reflexive pull back against the movement. How is this muscle control achieved?
A) spinal interneurons release excitatory neurotransmitters on the motor neurons of effector muscles
B) sensory neurons release excitatory neurotransmitters on the motor neurons of effector muscles
C) sensory neurons release inhibitory neurotransmitters on the motor neurons of antagonist muscles
D) All of the choices are correct.

Question

Quizplus · Accepted Answer

The reflexive response involves spinal interneurons releasing excitatory neurotransmitters on the motor neurons of the effector muscles (biceps) to contract, while inhibitory signals are sent to the antagonist muscles (triceps) to relax.

When a Person Is Standing with Their Elbow Bent, and Someone