Q: During the depolarization phase of an action potential, which ion's permeability increases most rapidly, and what is the direction of its flow?

Na\textsuperscript{+} permeability increases; Na\textsuperscript{+} flows into the cell

Q: Which ion is the primary determinant of the resting membrane potential in neurons, and why?

K\textsuperscript{+}, because the membrane is most permeable to potassium at rest

Question 1

Which part of the neuron is primarily responsible for receiving chemical and electrical signals from other neurons and transmitting them toward the cell body?

Accepted Answer

Dendrites

Question 2

A patient has damage to the myelin sheath of their neurons. Which of the following is the most likely consequence?

Accepted Answer

Slower transmission of electrical impulses along the axon

Question 3

Which equation is most appropriate for calculating the resting membrane potential of a neuron, considering the relative permeability and concentration gradients of multiple ions?

Accepted Answer

Goldman-Hodgkin-Katz (GHK) equation

Question 4

During the depolarization phase of an action potential, which ion's permeability increases most rapidly, and what is the direction of its flow?

Accepted Answer

Na	extsuperscript{+} permeability increases; Na	extsuperscript{+} flows into the cell

Question 5

Which ion is the primary determinant of the resting membrane potential in neurons, and why?

Accepted Answer

K	extsuperscript{+}, because the membrane is most permeable to potassium at rest

Question 6

Which of the following best describes the absolute refractory period of an action potential?

Accepted Answer

No action potential can be generated, regardless of stimulus, because Na	extsuperscript{+} channels are inactivated

Question 7

A neuron is stimulated at the axon hillock and an action potential is generated. Which property of the action potential ensures that the signal does not decrease in strength as it travels down the axon?

Accepted Answer

It is non-decremental

Question 8

Which glial cell type is responsible for myelinating axons in the central nervous system (CNS)?

Accepted Answer

Oligodendrocytes

Question 9

What is the main function of the nodes of Ranvier in a myelinated axon?

Accepted Answer

Regenerate action potentials due to high concentration of voltage-gated Na	extsuperscript{+} and K	extsuperscript{+} channels

Question 10

Which of the following molecules can cross the blood-brain barrier most easily?

Accepted Answer

Small lipid-soluble molecules

Question 11

A patient presents with receptive aphasia after a stroke. Which brain region is most likely affected?

Accepted Answer

Wernicke's area

Question 12

Which cranial nerve is responsible for transmitting visual information from the eyes to the brain?

Accepted Answer

Optic nerve (II)

Question 13

Which brain structure acts as the major relay station for sensory information, directing signals to the appropriate cortical areas?

Accepted Answer

Thalamus

Question 14

Which lobe of the brain is primarily responsible for voluntary movement, problem solving, and planning?

Accepted Answer

Frontal lobe

Question 15

Which of the following best describes the role of astrocytes in the CNS?

Accepted Answer

Form the blood-brain barrier and regulate the chemical environment

Question 16

Which equation describes the relationship between current flow, voltage, and resistance in neurons according to Ohm's Law?

Accepted Answer

$$I = V \div R$$

Question 17

Which neurotransmitter system is most associated with movement control and reward pathways in the brain?

Accepted Answer

Dopaminergic system

Question 18

Which type of memory involves the conscious recall of facts, events, and experiences, and is primarily associated with the hippocampus and medial temporal lobe?

Accepted Answer

Declarative (explicit) memory

Question 19

Which glial cell type in the CNS acts as the main immune defense, removing debris and pathogens by phagocytosis?

Accepted Answer

Microglia

Question 20

A patient has difficulty producing speech but can understand language. Which brain area is most likely damaged?

Accepted Answer

Broca's area

Neurons, Glial Cells, and Central Nervous System: Structure and Function Study Guide

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