Q: What is the definition of excitation-contraction coupling?
A: The link between the action potential and myofilament activation
Q: What neurotransmitter is released at the NMJ?
A: Acetylcholine (ACh).
Q: What ions move when the ACh receptor opens?
A: Na■ enters and K■ exits the muscle fiber.
Q: What is 'excitation' in the context of muscle physiology?
A: The process where an action potential in a nerve fiber leads to one in a muscle fiber.
Q: The presynaptic side of the NMJ ends in what structure?
A: Synaptic knob.
Q: When the nerve action potential reaches the axon terminal, which channels open?
A: Voltage-gated calcium channels.
Q: How many ACh molecules are released into the synaptic cleft per signal?
A: About 10,000.
Q: What is the small gap between the neuron and muscle fiber called?
A: Synaptic cleft.
Q: What type of receptor does ACh bind to on the muscle membrane?
A: Ligand-gated ACh receptor.
Q: What happens to the muscle membrane when Na enters?
A: It depolarizes..
Q: The action potential travels along the muscle fiber membrane called the:
A: Sarcolemma.
Q: What structure carries the action potential deep into the muscle fiber?
A: Transverse (T) tubules.
Q: What does the sarcoplasmic reticulum (SR) release in response to the action potential?
A: Calcium ions (Ca²■).
Q: What does calcium bind to in the thin filament?
A: The link between the action potential and myofilament activation
Q: What neurotransmitter is released at the NMJ?
A: Acetylcholine (ACh).
Q: What ions move when the ACh receptor opens?
A: Na■ enters and K■ exits the muscle fiber.
Q: What is 'excitation' in the context of muscle physiology?
A: The process where an action potential in a nerve fiber leads to one in a muscle fiber.
Q: The presynaptic side of the NMJ ends in what structure?
A: Synaptic knob.
Q: When the nerve action potential reaches the axon terminal, which channels open?
A: Voltage-gated calcium channels.
Q: How many ACh molecules are released into the synaptic cleft per signal?
A: About 10,000.
Q: What is the small gap between the neuron and muscle fiber called?
A: Synaptic cleft.
Q: What type of receptor does ACh bind to on the muscle membrane?
A: Ligand-gated ACh receptor.
Q: What happens to the muscle membrane when Na enters?
A: It depolarizes..
Q: The action potential travels along the muscle fiber membrane called the:
A: Sarcolemma.
Q: What structure carries the action potential deep into the muscle fiber?
A: Transverse (T) tubules.
Q: What does the sarcoplasmic reticulum (SR) release in response to the action potential?
A: Calcium ions (Ca²■).
Q: What does calcium bind to in the thin filament?