Muscular System: The Neuromuscular Junction
1. Synaptic vesicles in the axon terminal of a motor neuron contain what neurotransmitter?
- Acetylcholine
2. By what means of membrane transport does the neurotransmitter leave the axon terminal?
- Exocytosis
3. What ion diffuses into the axon terminal to stimulate the release of acetylcholine?
- Ca2 and influx cause synaptic vesicles which package neurotransmitters to attach
to the presynaptic membrane and exocytosis acetylcholine into the synaptic cleft.
4. In order to contract, a muscle fiber must be stimulated by what type of cell from the nervous
system?
- motor neuron
5. What is the name for the specialized region of the muscle fiber that contains acetylcholine
receptors?
- end plate
6. What is the synapse between a motor neuron and a skeletal muscle fiber called?
- neuromuscular junction (NMJ)
7. What ion diffuses through chemically gated channels of the junctional folds to alter the
membrane potential?
- acetylcholine (ACh)
8. What happens to chemically-gated channels when acetylcholine binds to them?
- It binds to receptor locations on the motor end plate’s chemically regulated ion channels.
9. What happens to chemically-gated channels when acetylcholine is removed from the synaptic
cleft?
1. Synaptic vesicles in the axon terminal of a motor neuron contain what neurotransmitter?
- Acetylcholine
2. By what means of membrane transport does the neurotransmitter leave the axon terminal?
- Exocytosis
3. What ion diffuses into the axon terminal to stimulate the release of acetylcholine?
- Ca2 and influx cause synaptic vesicles which package neurotransmitters to attach
to the presynaptic membrane and exocytosis acetylcholine into the synaptic cleft.
4. In order to contract, a muscle fiber must be stimulated by what type of cell from the nervous
system?
- motor neuron
5. What is the name for the specialized region of the muscle fiber that contains acetylcholine
receptors?
- end plate
6. What is the synapse between a motor neuron and a skeletal muscle fiber called?
- neuromuscular junction (NMJ)
7. What ion diffuses through chemically gated channels of the junctional folds to alter the
membrane potential?
- acetylcholine (ACh)
8. What happens to chemically-gated channels when acetylcholine binds to them?
- It binds to receptor locations on the motor end plate’s chemically regulated ion channels.
9. What happens to chemically-gated channels when acetylcholine is removed from the synaptic
cleft?
