Locomotion And Movement Question 10
Question: Muscle contraction is triggered:
Options:
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.
Show Answer
Answer:
Correct Answer: D
Solution:
[d] Muscle contraction is triggered by a nerve releasing a neurotransmitter, which in turn triggers the sarcoplasmic reticulum to release calcium ions into the muscle interior where they bind to troponin, thus causing tropomyosin to shift from the face of the actin filament to which myosin heads need to bind to produce contraction.
BETA
