Match each term with its corresponding description regarding the sliding-filament theory.
-Chemical released by the motor neuron that initiates the stimulus for a muscle contraction

Question

Quizplus · Accepted Answer

Acetylcholine is the chemical released by the motor neuron that initiates the stimulus for a muscle contraction.

Answer: F
 Calcium is the ion that binds to troponin, causing a shift in the position of tropomyosin, which then exposes the binding sites on the actin filament for the myosin heads to attach, leading to muscle contraction.

Answer: E
 ATP is the primary source of energy for muscle contraction, providing the energy needed for the myosin heads to detach from actin and for the repositioning of the cross-bridges during the contraction cycle.

Answer: G
 Cross-bridges form between the myosin heads and the exposed binding sites on the actin filament, and their movement during the contraction cycle pulls the actin filament closer to the center of the sarcomere, causing muscle contraction.

Answer: A and H
 Troponin and tropomyosin work together to regulate muscle contraction by blocking or allowing the attachment of myosin heads to actin, depending on the presence or absence of calcium ions.

Match Each Term with Its Corresponding Description Regarding the Sliding-Filament