Question 1

Which of the following best describes the primary contributors to the resting membrane potential in neurons?

Accepted Answer

The sodium-potassium pump, ion channels, and selective permeability of the cell membrane

Question 2

A neuron is exposed to a drug that blocks potassium channels. What is the most likely effect on the neuron's action potential?

Accepted Answer

Repolarization will be delayed, prolonging the action potential

Question 3

Which statement best explains the 'all-or-none' principle of action potentials?

Accepted Answer

An action potential either occurs fully or not at all, once threshold is reached

Question 4

During the absolute refractory period, which of the following is true?

Accepted Answer

No new action potential can be generated, regardless of stimulus strength

Question 5

Which of the following best describes graded potentials?

Accepted Answer

They vary in magnitude depending on stimulus strength and can be depolarizing or hyperpolarizing

Question 6

A patient is unable to feel pain or temperature changes in their skin. Which type of receptor is most likely malfunctioning?

Accepted Answer

Free nerve endings

Question 7

Which of the following is a correct example of a tonic receptor?

Accepted Answer

A photoreceptor in the eye that continues to respond to light after entering a dark room

Question 8

Which cranial nerve is purely sensory and responsible for the sense of smell?

Accepted Answer

Olfactory nerve

Question 9

Which of the following best describes the function of pacemaker cells in cardiac muscle?

Accepted Answer

They spontaneously generate action potentials without external input

Question 10

A person touches a hot stove and quickly withdraws their hand. Which type of receptor is primarily responsible for detecting the pain?

Accepted Answer

Nociceptors

Question 11

Which of the following best explains why the brain allocates more space to the upper lip, tongue, and face in the sensory cortex?

Accepted Answer

These areas have a higher density of sensory receptors

Question 12

Which of the following is true about the relative refractory period?

Accepted Answer

A stronger-than-normal stimulus is required to generate an action potential

Question 13

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

Accepted Answer

It actively transports 3 Na$^+$ ions out and 2 K$^+$ ions into the cell, maintaining a negative interior

Question 14

A patient has a mutation that causes their chloride channels to remain open longer than normal. What is the most likely effect on their neurons?

Accepted Answer

The neurons will be hyperpolarized and less likely to generate action potentials

Question 15

Which of the following best describes the function of mechanoreceptors in the skin?

Accepted Answer

They detect touch, pressure, and vibration

Question 16

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

Accepted Answer

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

Question 17

A person is exposed to a cold environment for an extended period. Which type of receptor is primarily responsible for detecting the temperature change?

Accepted Answer

Thermoreceptors

Question 18

Which of the following best explains why synaptic transmission is not a direct contributor to the resting membrane potential?

Accepted Answer

Synaptic transmission involves neurotransmitter release, which is a separate process from ion distribution at rest

Question 19

Which of the following is an example of a graded potential in a real-life scenario?

Accepted Answer

A small touch on the skin causing a slight depolarization in a sensory neuron

Question 20

Which of the following best describes the function of the blood-brain barrier in relation to endothelial cells and astrocytes?

Accepted Answer

It regulates the flow of materials into the brain, protecting neural tissue from toxins

Resting Membrane Potential and Action Potentials: Key Concepts for General Chemistry

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