Which of the following correctly lists the sequence of structures that action potentials must move through to excite skeletal muscle contraction?
A)sarcolemma,axon of neuron,T tubules
B)T tubules,sarcolemma,myofilament
C)muscle fiber,axon of neuron,myofibrils
D)axon of neuron,sarcolemma,T tubules
E)myofibrils,myofilaments,mitochondria

Question

Quizplus · Accepted Answer

Action potentials must first travel along the axon of a neuron, then reach the sarcolemma (cell membrane) of the muscle fiber, and finally enter the T-tubules which are extensions of the sarcolemma that penetrate deep into the muscle fiber. This triggers the release of calcium ions from the sarcoplasmic reticulum which then leads to muscle contraction. The other choices do not accurately describe the sequence of structures involved in skeletal muscle contraction.

Which of the Following Correctly Lists the Sequence of Structures