Question 1

Which region of the neuron is primarily responsible for the reception of synaptic inputs?

Accepted Answer

Dendrites

Question 2

The resting membrane potential of a neuron is mainly established by which of the following mechanisms?

Accepted Answer

Differences in ion concentration and selective permeability of the membrane

Question 3

Which equation best describes the equilibrium potential for a single ion across a neuronal membrane?

Accepted Answer

$$E_{ion} = \frac{RT}{zF} \ln \frac{[ion]_{out}}{[ion]_{in}}$$

Question 4

A patient is given a drug that blocks voltage-gated sodium channels. What effect will this have on neuronal signaling?

Accepted Answer

It will prevent the initiation and propagation of action potentials.

Question 5

Which of the following best describes the difference between graded potentials and action potentials?

Accepted Answer

Graded potentials are brief, short-distance signals; action potentials are brief, long-distance signals.

Question 6

During synaptic transmission at a chemical synapse, which event directly triggers neurotransmitter release?

Accepted Answer

Influx of $$Ca^{2+}$$ through voltage-gated calcium channels

Question 7

Which neurotransmitter is the main excitatory neurotransmitter in the central nervous system?

Accepted Answer

Glutamate

Question 8

What is the effect of an inhibitory postsynaptic potential (IPSP) on the postsynaptic neuron?

Accepted Answer

It hyperpolarizes the membrane, moving it further from threshold.

Question 9

Which process is responsible for the termination of neurotransmitter effects at a chemical synapse?

Accepted Answer

Reuptake by transporters, diffusion away from the synapse, or enzymatic degradation

Question 10

A neuron receives simultaneous excitatory inputs from multiple presynaptic neurons. This is an example of:

Accepted Answer

Spatial summation

Question 11

Which of the following best explains why the axon initial segment is the most likely site for action potential initiation?

Accepted Answer

It has the highest concentration of voltage-gated sodium channels.

Question 12

Which of the following is a real-world example of synaptic plasticity?

Accepted Answer

Learning a new skill and forming new memories

Question 13

Which of the following would most likely increase the strength of synaptic transmission?

Accepted Answer

Increasing the amount of neurotransmitter released

Question 14

A selective serotonin reuptake inhibitor (SSRI) is used as an antidepressant. What is its primary mechanism of action?

Accepted Answer

It inhibits the reuptake of serotonin from the synaptic cleft.

Question 15

Which of the following is true about electrical synapses?

Accepted Answer

They allow direct passage of ions through gap junctions.

Question 16

Which of the following best describes the effect of temporal summation?

Accepted Answer

A single presynaptic neuron fires repeatedly in rapid succession.

Question 17

Which of the following ions is most responsible for the depolarizing phase of the action potential?

Accepted Answer

$$Na^{+}$$ influx

Question 18

A mutation causes the postsynaptic cell to lack functional neurotransmitter receptors. What is the most likely consequence?

Accepted Answer

Synaptic transmission will be impaired, and postsynaptic potentials will not be generated.

Question 19

Which of the following best describes the chemoaffinity hypothesis in neural development?

Accepted Answer

Axons are guided to their targets by specific chemical cues.

Question 20

Which of the following would most likely result in synaptic desensitization?

Accepted Answer

Continuous presence of neurotransmitter leading to reduced receptor response

Synapses: Mechanisms of Synaptic Transmission and Integration

Guida di studio - Domande di pratica