Q: Which equation correctly represents the net charge movement by the sodium-potassium pump per cycle?

$$3\ \mathrm{Na}^+\ \text{out} - 2\ \mathrm{K}^+\ \text{in} = 1\ \text{net positive charge out}$$

Question 1

Which of the following best describes the function of the sodium-potassium pump in maintaining the resting membrane potential of a neuron?

Accepted Answer

It actively transports three sodium ions out and two potassium ions in, resulting in a net negative charge inside the cell.

Question 2

A patient suffers a spinal cord injury that damages the axons of peripheral nerves. Which sequence best describes the process of regeneration in the PNS?

Accepted Answer

The axon and myelin sheath distal to the injury degenerate, phagocytes digest debris, growth processes form from the proximal end, neurolemmocytes and basal lamina form a regeneration tube, and the axon reconnects with the target cell.

Question 3

Which of the following statements about myelination in the CNS and PNS is correct?

Accepted Answer

Oligodendrocytes in the CNS can myelinate parts of several axons, while neurolemmocytes in the PNS encircle a portion of a single axon only.

Question 4

A neuron receives simultaneous input from several presynaptic neurons, each causing an EPSP. What is this process called, and what is its effect?

Accepted Answer

Spatial summation; the postsynaptic neuron is more likely to reach threshold.

Question 5

Which of the following best explains why action potentials propagate in only one direction along an axon?

Accepted Answer

The membrane behind the action potential is still in the refractory period and cannot be depolarized.

Question 6

Which equation correctly represents the net charge movement by the sodium-potassium pump per cycle?

Accepted Answer

$$3\ \mathrm{Na}^+\ 	ext{out} - 2\ \mathrm{K}^+\ 	ext{in} = 1\ 	ext{net positive charge out}$$

Question 7

During an action potential, which sequence of events occurs at the axolemma?

Accepted Answer

Voltage-gated sodium channels open, sodium enters causing depolarization; sodium channels inactivate, potassium channels open, potassium exits causing repolarization.

Question 8

Which of the following is a major function of astrocytes in the CNS?

Accepted Answer

Assisting in the formation of the blood-brain barrier.

Question 9

A patient is prescribed a selective serotonin reuptake inhibitor (SSRI) for depression. What is the primary effect of this medication on synaptic transmission?

Accepted Answer

It prolongs the lifespan of serotonin in the synaptic cleft by inhibiting its reuptake into the presynaptic neuron.

Question 10

Which neurotransmitter is most important for excitatory transmission in the brain, and what type of postsynaptic potential does it typically produce?

Accepted Answer

Glutamate; excitatory postsynaptic potential (EPSP)

Question 11

Which structural classification of neurons is most prevalent in the human nervous system?

Accepted Answer

Multipolar neurons

Question 12

Which of the following best describes the difference between ionotropic and metabotropic neurotransmitter receptors?

Accepted Answer

Ionotropic receptors are part of ligand-gated ion channels and produce rapid, short-lived effects; metabotropic receptors are linked to G-proteins and produce slower, longer-lasting effects.

Question 13

Which of the following is true regarding the refractory period of a neuron?

Accepted Answer

During the absolute refractory period, voltage-gated sodium channels are in their activated and inactivated states and cannot be reactivated.

Question 14

Which type of neuronal circuit allows a single input neuron to communicate with multiple parts of the brain or body?

Accepted Answer

Diverging circuit

Question 15

A patient experiences recurrent episodes of abnormal, disorganized electrical activity in the brain, resulting in seizures. Which mechanism is most likely lost, leading to this condition?

Accepted Answer

Inhibitory negative feedback mechanisms within neuronal pools

Question 16

Which of the following best describes saltatory conduction in myelinated axons?

Accepted Answer

Action potentials 'jump' from one node of Ranvier to the next, increasing conduction speed.

Question 17

Which of the following is a correct match between a neurotransmitter and its primary function?

Accepted Answer

Serotonin: mood regulation

Question 18

Which equation best represents the change in membrane potential during an action potential?

Accepted Answer

$$V_{	ext{rest}} ightarrow V_{	ext{threshold}} ightarrow +30\ 	ext{mV} ightarrow V_{	ext{rest}}$$

Introduction to the Nervous System and Nervous Tissue

스터디 가이드 - 연습 문제

학습 가이드 - 플래시카드