Question

A disease deactivates the acetylcholine receptors at myoneural junctions. Would this prevent muscle contraction or muscle relaxation, and why?
Relaxation, by preventing synaptic vesicles from releasing their contents
Contraction, by preventing synaptic vesicles from releasing their contents
Relaxation, by preventing an action potential from traveling across the sarcolemma
Contraction, by preventing an action potential from traveling across the sarcolemma

Answer 1

I think the correct answer is D. contraction, by preventing an action potential from traveling across the sarcolemma. Acetycholine lreceptors are found on the surface of muscle cells, concentrated in the synapse between nerve cells and muscle cells. When the nerve impulses reaches the axon terminals, a chemical called the neurotransmitter is released, in this case the acetylcholine that stimulates skeletal muscle cell. Therefore a disease that inactivates the acetylcholine will prevent the activation of the muscle.