Question 1

Which of the following best describes the process by which neurotransmitters are released from the presynaptic terminal?

Accepted Answer

Neurotransmitters are released via Ca$$^{2+}-$$mediated exocytosis, where voltage-gated Ca$$^{2+}$$ channels open in response to an action potential, allowing Ca$$^{2+}$$ influx that triggers vesicle fusion with the membrane.

Question 2

A patient is given a drug that inhibits acetylcholinesterase (AChE). What is the most likely effect on synaptic transmission at cholinergic synapses?

Accepted Answer

Acetylcholine will accumulate in the synaptic cleft, leading to prolonged stimulation of the postsynaptic cell.

Question 3

Which of the following best explains spatial summation in neural integration?

Accepted Answer

Multiple presynaptic neurons release neurotransmitter at different locations on the postsynaptic neuron simultaneously, and their combined effects can reach threshold.

Question 4

Which of the following is a correct pairing of neurotransmitter and its primary receptor type?

Accepted Answer

Glutamate — AMPA receptor (ICR for Na$$^+$$, K$$^+)$$

Question 5

A neuron receives one excitatory postsynaptic potential (EPSP) and one inhibitory postsynaptic potential (IPSP) at the same time. What is the likely outcome at the axon hillock?

Accepted Answer

The EPSP and IPSP will summate, and the net effect will determine whether threshold is reached.

Question 6

Which of the following mechanisms is NOT a way to terminate neurotransmitter activity in the synaptic cleft?

Accepted Answer

Conversion of neurotransmitter into a different neurotransmitter by the postsynaptic cell.

Question 7

Which of the following best describes the role of the SNARE complex in neurotransmitter release?

Accepted Answer

It mediates the fusion of synaptic vesicles with the presynaptic membrane, allowing neurotransmitter exocytosis.

Question 8

A neuron is exposed to a toxin that blocks voltage-gated Ca$$^{2+}$$ channels. What is the most immediate effect on synaptic transmission?

Accepted Answer

Neurotransmitter release will be inhibited because vesicle fusion is Ca$$^{2+}-$$dependent.

Question 9

Which of the following is an example of postsynaptic modulation?

Accepted Answer

Changing the number or affinity of neurotransmitter receptors on the postsynaptic cell.

Question 10

Which of the following best describes temporal summation?

Accepted Answer

Multiple EPSPs from the same presynaptic neuron arrive at the postsynaptic neuron in rapid succession, allowing their effects to add together.

Question 11

A patient is given a drug that acts as an agonist at muscarinic acetylcholine receptors. Which of the following is a likely effect?

Accepted Answer

Increased parasympathetic activity, such as decreased heart rate.

Question 12

Which of the following statements about convergence and divergence in neural circuits is correct?

Accepted Answer

Convergence refers to multiple presynaptic neurons synapsing onto a single postsynaptic neuron, while divergence refers to one presynaptic neuron synapsing onto multiple postsynaptic neurons.

Question 13

Which of the following neurotransmitters is correctly matched with a clinical antagonist?

Accepted Answer

Serotonin (5-HT) — LSD

Question 14

A neuron is exposed to a drug that increases the number of AMPA receptors on its postsynaptic membrane. What is the most likely effect on synaptic transmission?

Accepted Answer

The postsynaptic cell will have a greater response to glutamate, increasing the likelihood of reaching threshold.

Question 15

Which of the following best describes the effect of axo-axonic synapses?

Accepted Answer

They modulate neurotransmitter release from the presynaptic terminal, either facilitating or inhibiting it.

Question 16

Which of the following is a correct statement about the synthesis and packaging of peptide neurotransmitters?

Accepted Answer

Peptide neurotransmitters are synthesized and packaged into vesicles in the soma and transported to the axon terminal via fast axonal transport.

Question 17

A neuron is exposed to a drug that blocks reuptake of serotonin (5-HT) into the presynaptic terminal. What is the most likely effect?

Accepted Answer

Serotonin will remain in the synaptic cleft longer, prolonging its action on the postsynaptic cell.

Question 18

Which of the following is a feature of inhibitory postsynaptic potentials (IPSPs)?

Accepted Answer

They often result from the opening of K$$^+ or Cl$^-$$ channels, leading to hyperpolarization of the postsynaptic membrane.

Question 19

A patient is given a drug that acts as an antagonist at glycine receptors. What is the most likely effect on neural activity?

Accepted Answer

Reduced inhibitory signaling in the CNS, potentially leading to convulsions or hyperexcitability.

Neural Communication and Synaptic Integration: Study Notes for Anatomy & Physiology

Guida di studio - Domande di pratica

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