Question 1

Which of the following best describes the main function of the sympathetic division of the autonomic nervous system?

Accepted Answer

It mobilizes the body for activity, increasing heart rate and dilating pupils.

Question 2

Which type of neuron is characterized by having a single process that splits into two branches, one acting as an axon and the other as a dendrite?

Accepted Answer

Pseudounipolar neuron

Question 3

Which glial cell type is responsible for forming myelin sheaths in the peripheral nervous system?

Accepted Answer

Schwann cells

Question 4

A patient with Alzheimer’s disease is found to have disrupted axonal transport. Which of the following best explains this phenomenon?

Accepted Answer

Hyperphosphorylated tau protein destabilizes microtubules, and amyloid-beta oligomers impair motor proteins.

Question 5

Which equation predicts the equilibrium potential for a single ion across a membrane?

Accepted Answer

Nernst equation: $$E_{ion} = \frac{61}{z} \log \frac{[ion]_{out}}{[ion]_{in}}$$

Question 6

If the permeability of the neuronal membrane to K+ suddenly decreases, what is the immediate effect on the membrane potential?

Accepted Answer

The cell depolarizes.

Question 7

Which of the following is a unique property of graded potentials compared to action potentials?

Accepted Answer

They can be summed and vary in amplitude.

Question 8

A neuron’s resting membrane potential is closest to the equilibrium potential of which ion, and why?

Accepted Answer

K+, because the membrane has many K+ leak channels.

Question 9

Which of the following best describes the role of astrocytes in the central nervous system?

Accepted Answer

They take up K+, water, and neurotransmitters, secrete neurotrophic factors, help form the blood-brain barrier, and provide substrates for ATP production.

Question 10

Which of the following scenarios would most likely result in permanent paralysis after injury?

Accepted Answer

Severing the axon of a motor neuron in the PNS.

Question 11

Which of the following is a correct application of the Goldman-Hodgkin-Katz (GHK) equation?

Accepted Answer

Calculating the membrane potential considering the relative permeabilities and concentrations of multiple ions.

Question 12

Which of the following best explains why graded potentials decrease in strength as they move through the neuron?

Accepted Answer

They lose strength due to current leak and cytoplasmic resistance.

Question 13

Which of the following is a distinguishing feature of anaxonic neurons?

Accepted Answer

They have no axon.

Question 14

Which of the following best describes the effect of amyloid-beta oligomers in Alzheimer’s disease?

Accepted Answer

They disrupt motor protein function, impairing cargo movement along axons.

Question 15

Which of the following is a correct statement about the nodes of Ranvier?

Accepted Answer

They are gaps in the myelin sheath where action potentials are regenerated.

Question 16

Which of the following best explains why the resting membrane potential is negative?

Accepted Answer

The membrane is more permeable to K+ than to Na+, and K+ leaves the cell, making the inside more negative.

Question 17

Which of the following is a consequence of Schwann cell activity after peripheral nerve injury?

Accepted Answer

They clear debris and guide regrowing axons toward their targets.

Question 18

Which of the following best describes the role of dendritic spines in learning and memory?

Accepted Answer

They undergo growth and stabilization, increasing mature spines.

Question 19

Which of the following is a correct match between a glial cell and its function?

Accepted Answer

Oligodendrocytes – form myelin sheaths in the CNS

Neurons: Cellular and Network Properties – Study Notes

Guida di studio - Domande di pratica

Study guide - Flashcard