Q: Which of the following equations best represents the condition for action potential generation at the postsynaptic neuron?

$$\text{Excitatory input} \u003e \text{Inhibitory input}$$, \text{and} \text{Net input} \geq \text{Threshold}$

Q: Which of the following scenarios would result in inhibition of the postsynaptic neuron?

$$\text{Inhibitory input} \u003e \text{Excitatory input}$$

Question 1

Which of the following best describes the process of temporal summation at a chemical synapse?

Accepted Answer

Graded potentials arrive at the postsynaptic neuron in rapid succession, allowing them to add together over time.

Question 2

A postsynaptic neuron receives three excitatory inputs and one inhibitory input. The net graded potential at the trigger zone is above threshold. What will most likely occur?

Accepted Answer

An action potential will be generated.

Question 3

Which of the following mechanisms is NOT a way neurotransmitter effects are terminated at the synapse?

Accepted Answer

Conversion of neurotransmitter into an action potential.

Question 4

Which type of synaptic circuit is responsible for amplifying a signal so that one neuron can activate many motor neurons and muscle fibers?

Accepted Answer

Diverging circuit

Question 5

A drug acts as an antagonist at a neurotransmitter receptor. What is its most likely effect?

Accepted Answer

It blocks the action of the neurotransmitter.

Question 6

Which of the following equations best represents the condition for action potential generation at the postsynaptic neuron?

Accepted Answer

$$	ext{Excitatory input} \u003e 	ext{Inhibitory input}$$, 	ext{and} 	ext{Net input} \geq 	ext{Threshold}$

Question 7

Which of the following is TRUE regarding channel-linked receptors?

Accepted Answer

They open or close membrane ion channels rapidly, leading to depolarization or hyperpolarization.

Question 8

A patient is given a drug that blocks the reuptake of neurotransmitter into the presynaptic cell. What is the most likely effect on synaptic transmission?

Accepted Answer

Neurotransmitter remains longer in the synaptic cleft, prolonging its effect.

Question 9

Which of the following best describes spatial summation?

Accepted Answer

Simultaneous graded potentials from multiple presynaptic neurons combine at the postsynaptic membrane.

Question 10

Which of the following is a function of G protein-linked receptors in postsynaptic cells?

Accepted Answer

Activate intracellular second messengers that can modulate ion channels, enzymes, or protein synthesis.

Question 11

Which of the following scenarios would result in inhibition of the postsynaptic neuron?

Accepted Answer

$$	ext{Inhibitory input} \u003e 	ext{Excitatory input}$$

Question 12

Which of the following is an example of a converging circuit in the nervous system?

Accepted Answer

Multiple photoreceptor cells in the retina synapsing onto a single sensory neuron.

Question 13

Which of the following is NOT a possible effect of neurotransmitter binding to its receptor on the postsynaptic cell?

Accepted Answer

Direct conversion of neurotransmitter into ATP.

Question 14

Presynaptic inhibition most directly affects which aspect of synaptic transmission?

Accepted Answer

The amount of neurotransmitter released from the presynaptic neuron.

Question 15

Which of the following statements about neurotransmitter effects is TRUE?

Accepted Answer

The effect of a neurotransmitter depends on both the type of neurotransmitter and the receptor it binds to.

Question 16

A patient is exposed to a toxin that blocks enzymatic inactivation of neurotransmitters at the synapse. What is the most likely consequence?

Accepted Answer

Neurotransmitter effects will be prolonged due to decreased breakdown.

Question 17

Which of the following best describes the role of the postsynaptic neuron at the trigger zone?

Accepted Answer

It acts as an integrator of excitatory and inhibitory signals to determine if an action potential will be generated.

Question 18

Which of the following is a real-world example of presynaptic facilitation?

Accepted Answer

Serotonin release increases calcium entry into the presynaptic terminal, enhancing neurotransmitter release.

Question 19

Which of the following equations best represents the net effect of spatial summation at the trigger zone?

Accepted Answer

$$V_{	ext{total}} = \sum_{i=1}^{n} V$$_{	ext{EPSP}$$_i} - \sum_{j=1}^{m} V$$_{	ext{IPSP}$$_j}$$

Neurophysiology: Synaptic Transmission Study Notes

Study Guide - Practice Questions

Study Guide - Flashcards