Podcast
Questions and Answers
What triggers the release of acetylcholine into the synaptic cleft at the neuromuscular junction?
What triggers the release of acetylcholine into the synaptic cleft at the neuromuscular junction?
- Propagation of action potential along the sarcolemma
- Generation of action potential in the muscle fiber
- Arrival of an action potential in the motor neuron (correct)
- Binding of acetylcholine to receptors on the motor end plate
What does acetylcholine bind to on the muscle fiber?
What does acetylcholine bind to on the muscle fiber?
- Sarcoplasmic reticulum (SR) membrane
- Troponin on actin filaments
- Receptors on the motor end plate (correct)
- T-tubules on the sarcolemma
What triggers an action potential along the sarcolemma of a muscle cell?
What triggers an action potential along the sarcolemma of a muscle cell?
- Binding of calcium ions to troponin
- End-plate potential (EPP) reaching the threshold (correct)
- Propagation of action potential in the motor neuron
- Release of acetylcholine into the synaptic cleft
Where does the action potential travel along before penetrating into the muscle fiber?
Where does the action potential travel along before penetrating into the muscle fiber?
What signals the release of calcium ions from the sarcoplasmic reticulum (SR) in a muscle cell?
What signals the release of calcium ions from the sarcoplasmic reticulum (SR) in a muscle cell?
What do calcium ions bind to in a muscle cell?
What do calcium ions bind to in a muscle cell?
What causes the exposure of myosin-binding sites on actin filaments?
What causes the exposure of myosin-binding sites on actin filaments?
What provides energy for the myosin heads to pull the actin filaments?
What provides energy for the myosin heads to pull the actin filaments?
What leads to the relaxation of the muscle fiber?
What leads to the relaxation of the muscle fiber?
What binds to the exposed sites on actin, forming cross-bridges?
What binds to the exposed sites on actin, forming cross-bridges?
What causes the sarcomere to shorten and the muscle to contract?
What causes the sarcomere to shorten and the muscle to contract?
