$E_{K^+} = \frac{RT}{zF} \ln \left( \frac{[K^+]_{\text{outside}}}{[K^+]_{\text{inside}}} \right)$

Question 1

Which division of the nervous system is primarily responsible for voluntary movement, such as lifting a weight during exercise?

Accepted Answer

Somatic/motor division of the peripheral nervous system

Question 2

A patient with multiple sclerosis experiences muscle weakness and slowed reflexes. Which cellular structure is most likely affected?

Accepted Answer

Myelin sheath

Question 3

What is the typical resting membrane potential of a neuron, and what is the main reason for this value?

Accepted Answer

$-70\ \mathrm{mV}$, due to differences in ionic concentrations and membrane permeability

Question 4

Which equation best describes the equilibrium potential for potassium ions ($K^+$) across a neuronal membrane?

Accepted Answer

$E_{K^+} = \frac{RT}{zF} \ln \left( \frac{[K^+]_{	ext{outside}}}{[K^+]_{	ext{inside}}} ight)$

Question 5

During an action potential, which event occurs immediately after the membrane potential reaches threshold at the axon hillock?

Accepted Answer

Voltage-gated sodium channels open, causing rapid depolarization

Question 6

Which of the following best explains why action potentials do not decrease in strength as they travel along an axon?

Accepted Answer

Action potentials are regenerated at each segment of the axon by voltage-gated ion channels

Question 7

A neurotransmitter binds to a ligand-gated ion channel on the postsynaptic neuron. What is the most immediate effect?

Accepted Answer

Generation of a graded (local) potential

Question 8

Which of the following neurotransmitters is primarily excitatory in the central nervous system?

Accepted Answer

Glutamate

Question 9

If a neuron receives multiple excitatory postsynaptic potentials (EPSPs) in rapid succession, what is the likely outcome?

Accepted Answer

The EPSPs will summate, possibly triggering an action potential

Question 10

Which glial cell type is responsible for myelinating axons in the peripheral nervous system?

Accepted Answer

Schwann cells

Question 11

A patient is unable to digest food properly due to a malfunction in the nervous system. Which division is most likely affected?

Accepted Answer

Enteric nervous system

Question 12

Which of the following best describes the role of the Na$^+$/K$^+$ ATPase pump in maintaining the resting membrane potential?

Accepted Answer

It actively transports 3 Na$^+$ out and 2 K$^+$ in, maintaining ionic gradients

Question 13

Which type of receptor mediates fast synaptic responses in neurons?

Accepted Answer

Ligand-gated ion channel receptors

Question 14

What is the main difference between graded potentials and action potentials?

Accepted Answer

Graded potentials vary in size and can summate, while action potentials are all-or-none

Question 15

Which of the following best describes hyperpolarization in a neuron?

Accepted Answer

The membrane potential becomes more negative than resting

Question 16

Which process is directly responsible for neurotransmitter release at the synaptic terminal?

Accepted Answer

Influx of calcium ions through voltage-gated channels

Question 17

A neuron receives both excitatory and inhibitory inputs. What determines whether it will fire an action potential?

Accepted Answer

The net effect of all graded potentials at the axon hillock

Question 18

Which of the following is a function of astrocytes in the nervous system?

Accepted Answer

Providing metabolic support and maintaining the blood-brain barrier

Question 19

Which equation describes the Nernst potential for a generic ion $X$?

Accepted Answer

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

Question 20

Which of the following best describes the role of the efferent division of the peripheral nervous system?

Accepted Answer

Carries motor commands from the central nervous system to effectors

Neurophysiology 1: The Nervous System, Neurons, and Cell-Cell Communication

Study Guide - Practice Questions