Muscle contraction is triggered
A)when high levels of oxygen and sugar are released by the sarcolemma.
B)when a surplus of ATP is released by a nerve motor unit.
C)by release of a neurotransmitter at a synapse that directly causes actin and myosin to slide.
D)by the nerve releasing a neurotransmitter,which triggers a flow of calcium that attaches to actin filaments and exposes the myosin binding sites.
E)by the nerve releasing a neurotransmitter,which triggers a flow of calcium that releases ATP and begins the actin filaments sliding across the myosin binding sites.

Question

Quizplus · Accepted Answer

Muscle contraction is initiated when a nerve releases a neurotransmitter (acetylcholine) at the neuromuscular junction, leading to a flow of calcium ions that bind to troponin on actin filaments, exposing the myosin binding sites and allowing contraction to occur.

Muscle Contraction Is Triggered