Q: Which equation best represents the likelihood of a neuron firing an action potential?

$$\text{Likelihood of Action Potential} \propto \frac{\text{EPSPs}}{\text{IPSPs}}$$

Question 1

Which of the following best explains why reflexes are slower than conduction along an axon?

Accepted Answer

The delay is due to the time required for communication between neurons at the synapse.

Question 2

A patient receives several weak stimuli at the same location on their skin in rapid succession, resulting in a strong reflex response. Which concept does this illustrate?

Accepted Answer

Temporal summation

Question 3

Which of the following best describes an inhibitory postsynaptic potential (IPSP)?

Accepted Answer

A temporary hyperpolarization of the membrane caused by the opening of K$$^+ or Cl$^-$$ channels.

Question 4

Which equation best represents the likelihood of a neuron firing an action potential?

Accepted Answer

$$	ext{Likelihood of Action Potential} \propto \frac{	ext{EPSPs}}{	ext{IPSPs}}$$

Question 5

Which neurotransmitter is synthesized from choline, a nutrient found in milk, eggs, and nuts?

Accepted Answer

Acetylcholine

Question 6

A neurotransmitter binds to a receptor and immediately opens an ion channel, causing a rapid and short-lived effect. This is an example of:

Accepted Answer

Ionotropic effect

Question 7

Which of the following best describes the role of neuromodulators?

Accepted Answer

They increase or decrease the release of other neurotransmitters and alter postsynaptic cell responses.

Question 8

Which hormone is synthesized in the hypothalamus and released by the posterior pituitary?

Accepted Answer

Oxytocin

Question 9

Which process describes the presynaptic neuron taking up most of the neurotransmitter molecules intact and reusing them?

Accepted Answer

Reuptake

Question 10

Which enzyme is responsible for breaking down acetylcholine in the synaptic cleft?

Accepted Answer

Acetylcholinesterase

Question 11

A drug that binds to a receptor but does not activate it, thereby blocking the action of a neurotransmitter, is called a(n):

Accepted Answer

Antagonist

Question 12

Which of the following drugs increases the release of dopamine from the presynaptic terminal?

Accepted Answer

Amphetamine

Question 13

Which of the following best explains why THC (the active ingredient in marijuana) can cause memory impairment and altered sensory experiences?

Accepted Answer

Cannabinoid receptors are located in brain regions such as the hippocampus, cortex, and cerebellum, affecting memory and perception.

Question 14

Which of the following is a correct statement about the mechanism of action of cocaine?

Accepted Answer

Cocaine blocks the reuptake of dopamine, norepinephrine, and serotonin.

Question 15

Which of the following best describes the effect of endorphins in the brain?

Accepted Answer

They inhibit the release of GABA, indirectly increasing dopamine release.

Question 16

A patient is prescribed a drug that blocks the breakdown of dopamine into inactive chemicals. Which enzyme is most likely being inhibited?

Accepted Answer

Monoamine oxidase (MAO)

Question 17

Which of the following best explains why almost all abused drugs stimulate dopamine release in the nucleus accumbens?

Accepted Answer

The nucleus accumbens is a subcortical area rich in dopamine receptors and is involved in the experience of pleasure.

Question 18

Which of the following drugs acts as an agonist at nicotinic acetylcholine receptors, facilitating dopamine release in the nucleus accumbens?

Accepted Answer

Nicotine

Question 19

Which of the following best describes the effect of hallucinogenic drugs such as LSD on the brain?

Accepted Answer

They stimulate serotonin type 2A receptors (5-HT2A) at inappropriate times or for longer durations.

Question 20

A patient is given a drug with high affinity but low efficacy for a specific receptor. What is the most likely effect of this drug?

Accepted Answer

It will bind to the receptor but not activate it, possibly blocking the action of endogenous neurotransmitters.

lecture exam 4: neural communication: synapses, neurotransmitters, and drug effects

Study Guide - Practice Questions

Study Guide - Flashcards