Q: Which of the following equations correctly represents the Nernst equation for calculating the equilibrium potential of an ion across a membrane?

$$E = \frac{RT}{zF} \ln \left( \frac{[\text{ion}]_{\text{out}}}{[\text{ion}]_{\text{in}}} \right)$$

Question 1

Which of the following best describes the function of Schwann cells (neurolemmocytes) in the peripheral nervous system?

Accepted Answer

They form the myelin sheath around axons, increasing the speed of nerve impulse conduction.

Question 2

A patient presents with muscle weakness and slowed reflexes. Demyelination of axons is suspected. Which cell type is most likely affected in the central nervous system?

Accepted Answer

Oligodendrocytes

Question 3

Which of the following equations correctly represents the Nernst equation for calculating the equilibrium potential of an ion across a membrane?

Accepted Answer

$$E = \frac{RT}{zF} \ln \left( \frac{[	ext{ion}]_{	ext{out}}}{[	ext{ion}]_{	ext{in}}} ight)$$

Question 4

During the depolarization phase of an action potential, which ion moves most rapidly across the neuronal membrane?

Accepted Answer

Sodium ions move into the cell.

Question 5

Which structure is responsible for receiving synaptic input from other neurons?

Accepted Answer

Dendrites

Question 6

A neurotransmitter binds to a postsynaptic receptor and causes an influx of Na$$^+$$ ions. What type of postsynaptic potential is generated?

Accepted Answer

Excitatory postsynaptic potential (EPSP)

Question 7

Which of the following best explains why myelinated axons conduct action potentials faster than unmyelinated axons?

Accepted Answer

Action potentials jump from one node of Ranvier to the next via saltatory conduction.

Question 8

Which glial cell type lines the ventricles of the brain and is involved in the production and circulation of cerebrospinal fluid?

Accepted Answer

Ependymal cells

Question 9

A neuron receives both excitatory and inhibitory inputs. If the sum of these inputs reaches the threshold at the axon hillock, what will occur?

Accepted Answer

An action potential will be generated and propagated down the axon.

Question 10

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

Accepted Answer

They form the blood-brain barrier and regulate the extracellular environment.

Question 11

Which of the following is the correct sequence of events during chemical synaptic transmission?

Accepted Answer

Action potential arrival, Ca$$^{2+}$$ influx, neurotransmitter release, postsynaptic receptor activation

Question 12

Which equation best represents Ohm's Law as applied to the movement of ions across a neuronal membrane?

Accepted Answer

$$V = I 	imes R$$

Question 13

A patient is diagnosed with multiple sclerosis, a disease characterized by demyelination in the CNS. Which process is most directly impaired?

Accepted Answer

Saltatory conduction of action potentials

Question 14

Which of the following best describes the refractory period of a neuron?

Accepted Answer

The period after an action potential when a neuron cannot initiate another action potential.

Question 15

Which of the following is a function of microglia in the central nervous system?

Accepted Answer

Acting as immune cells to remove debris and pathogens

Question 16

Which of the following best explains the effect of increasing the diameter of an axon on the velocity of action potential propagation?

Accepted Answer

It increases the velocity by reducing internal resistance to ion flow.

Question 17

Which of the following structures is NOT part of the neuron cell body?

Accepted Answer

Node of Ranvier

Question 18

Which of the following best describes the process of Wallerian degeneration?

Accepted Answer

The breakdown of the axon distal to the site of injury, followed by phagocytosis and possible regeneration.

Question 19

Which of the following is TRUE regarding voltage-gated Na$$^+$$ channels during an action potential?

Accepted Answer

They inactivate shortly after opening, contributing to the refractory period.

Nervous Tissue: Structure, Function, and Physiology Study Notes

Guida di studio - Domande di pratica

Study guide - Flashcard