Q: Which equation best represents the Nernst equation for calculating the equilibrium potential for an ion?

$$E = \frac{RT}{zF} \ln \frac{[\text{ion}]_{\text{outside}}}{[\text{ion}]_{\text{inside}}}$$

Question 1

Which of the following best describes the role of the axon hillock in a neuron?

Accepted Answer

It is the region where action potentials are typically initiated due to the summation of graded potentials.

Question 2

A patient is diagnosed with a disease that destroys oligodendrocytes. Which of the following would most likely be affected?

Accepted Answer

The speed of action potential conduction in the central nervous system.

Question 3

Which equation best represents the Nernst equation for calculating the equilibrium potential for an ion?

Accepted Answer

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

Question 4

During the rising phase of an action potential, which of the following occurs?

Accepted Answer

Voltage-gated Na+ channels open, causing Na+ to flow into the cell.

Question 5

Which of the following best explains why action potentials travel in only one direction along an axon?

Accepted Answer

The refractory period caused by inactivated Na+ channels prevents backward propagation.

Question 6

A toxin blocks voltage-gated K+ channels in neurons. What is the most likely effect on the action potential?

Accepted Answer

The repolarization phase will be prolonged, causing a longer action potential.

Question 7

Which of the following is a function of glial cells in the nervous system?

Accepted Answer

Insulating axons to increase the speed of action potential conduction.

Question 8

Which of the following best describes saltatory conduction?

Accepted Answer

Action potentials jump from one node of Ranvier to the next, increasing conduction speed.

Question 9

Which of the following events occurs at a chemical synapse?

Accepted Answer

Neurotransmitters are released from the presynaptic neuron and bind to receptors on the postsynaptic cell.

Question 10

A person accidentally touches a hot stove and quickly withdraws their hand. Which sequence best describes the flow of information in their nervous system?

Accepted Answer

Sensory input → Integration → Motor output

Question 11

Which of the following statements about graded potentials is correct?

Accepted Answer

Their magnitude varies with the strength of the stimulus.

Question 12

Which of the following would most likely occur if the Na+/K+ ATPase pump in a neuron stopped functioning?

Accepted Answer

The resting membrane potential would dissipate, and the neuron could not generate action potentials.

Question 13

Which of the following is true regarding the difference between the central nervous system (CNS) and the peripheral nervous system (PNS)?

Accepted Answer

The CNS is responsible for integration, while the PNS carries information to and from the CNS.

Question 14

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

Accepted Answer

Myelin allows action potentials to jump between nodes of Ranvier, reducing the number of times the membrane must depolarize.

Question 15

Which of the following is a correct sequence of events during the generation of an action potential?

Accepted Answer

Depolarization → Repolarization → Hyperpolarization → Resting state

Question 16

A neuron receives simultaneous excitatory and inhibitory inputs. Which of the following best describes what determines whether an action potential will be generated?

Accepted Answer

The sum of all graded potentials at the axon hillock must reach threshold.

Neurons, Synapses, and Signaling: Structure and Function in the Nervous System

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