Question : 121) Which type of synapse most common in the nervous : 2069378

121) Which type of synapse is most common in the nervous system?

A) chemical

B) electrical

C) mechanical

D) processing

E) radiative

122) The ion that triggers the release of acetylcholine into the synaptic cleft is

A) sodium.

B) potassium.

C) calcium.

D) chloride.

E) magnesium.

123) Cholinergic synapses release the neurotransmitter

A) norepinephrine.

B) adrenalin.

C) serotonin.

D) acetylcholine.

E) GABA.

124) The following are the steps involved in transmission at a cholinergic synapse. What is the correct sequence for these events?

1. Chemically-gated sodium channels on the postsynaptic membrane are activated.

2. Calcium ions enter the synaptic terminal.

3. Acetylcholinesterase hydrolyzes acetylcholine.

4. An action potential depolarizes the synaptic terminal at the presynaptic membrane.

5. The pre-synaptic terminal reabsorbs choline.

6. Acetylcholine is released from storage vesicles by exocytosis.

7. Acetylcholine binds to receptors on the postsynaptic membrane.

8. Calcium ions are removed from the cytoplasm of the pre- synaptic terminal.

A) 4, 2, 6, 7, 8, 5, 3, 1

B) 4, 2, 6, 7, 1, 8, 3, 5

C) 2, 4, 6, 7, 1, 8, 3, 5

D) 2, 5, 4, 6, 7, 1, 8, 3

E) 6, 4, 2, 7, 1, 8, 3, 5

125) If the chemically gated sodium channels in the postsynaptic membrane were completely blocked,

A) synaptic transmission would fail.

B) release of neurotransmitter would stop.

C) smaller action potentials would result.

D) the presynaptic membrane would be unable to reach threshold.

E) the presynaptic neuron would release a different neurotransmitter.