$3 \mathrm{Na}^+ \text{ out}, 2 \mathrm{K}^+ \text{ in}$

Question 1

Which part of a neuron is primarily responsible for transmitting information toward the cell body?

Accepted Answer

Dendrite

Question 2

What is the main function of the axon in a neuron?

Accepted Answer

To conduct nerve impulses away from the cell body

Question 3

During the resting potential, the inside of a neuron's axon is:

Accepted Answer

Negatively charged relative to the outside

Question 4

Which equation best represents the action of the sodium-potassium pump in maintaining resting potential?

Accepted Answer

$3 \mathrm{Na}^+ 	ext{ out}, 2 \mathrm{K}^+ 	ext{ in}$

Question 5

A graded potential in a neuron is best described as:

Accepted Answer

A small, variable change in membrane potential proportional to stimulus strength

Question 6

What event directly triggers the opening of voltage-gated sodium channels during an action potential?

Accepted Answer

Membrane depolarization reaching threshold potential

Question 7

Which of the following best describes the process of repolarization in a neuron?

Accepted Answer

Efflux of potassium ions

Question 8

The rapid transmission of an action potential along a myelinated axon is due to:

Accepted Answer

Saltatory conduction, where the action potential jumps from node to node

Question 9

At a chemical synapse, what is the correct sequence of events leading to neurotransmitter release?

Accepted Answer

Action potential arrives, calcium channels open, vesicles fuse with membrane, neurotransmitter released

Question 10

Which of the following best explains why grasshopper mice do not feel pain from scorpion venom?

Accepted Answer

Their sodium channels in pain receptors do not open in response to the venom

Question 11

A poison that holds sodium channels open in neurons would most likely cause:

Accepted Answer

Convulsions due to persistent depolarization

Question 12

Which of the following is an example of exocytosis in a neuron?

Accepted Answer

Release of neurotransmitters into the synaptic cleft

Question 13

Which organelle is directly involved in packaging proteins for secretion in the endomembrane system?

Accepted Answer

Golgi apparatus

Question 14

A neurotransmitter that increases the likelihood of an action potential in the postsynaptic cell is called:

Accepted Answer

Excitatory

Question 15

Which of the following best describes the role of serotonin reuptake inhibitors (SSRIs) in the nervous system?

Accepted Answer

They block the reuptake of serotonin, increasing its concentration in synaptic clefts

Question 16

If a neuron receives both excitatory and inhibitory signals at the same time, what determines whether it will fire an action potential?

Accepted Answer

The sum of all signals at the axon hillock

Question 17

Which of the following best explains why acetylcholinesterase inhibitors can cause muscle spasms?

Accepted Answer

They prevent the breakdown of acetylcholine, leading to continuous muscle stimulation

Question 18

Which of the following is the correct order of events for the secretion of a protein from a mammary gland cell?

Accepted Answer

Ribosome → rough ER → Golgi apparatus → transport vesicle → cell membrane

Question 19

A toxin that blocks acetylcholine receptors at the neuromuscular junction would most likely cause:

Accepted Answer

Muscle paralysis

Question 20

Which of the following best describes the function of the endomembrane system in a eukaryotic cell?

Accepted Answer

It coordinates the synthesis, modification, and transport of proteins and lipids

The Nervous System: Structure, Function, and Cellular Communication

Study Guide - Practice Questions