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

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

Question 1

Which of the following best describes the primary function of the blood-brain barrier (BBB)?

Accepted Answer

To regulate the composition of the extracellular fluid surrounding neurons and protect the brain from harmful chemicals.

Question 2

A patient with multiple sclerosis experiences muscle weakness due to demyelination. Which supporting cell type is primarily affected in the central nervous system?

Accepted Answer

Oligodendrocytes

Question 3

Which structure of a neuron is responsible for receiving information from other neurons?

Accepted Answer

Dendrites

Question 4

During the action potential, which ion movement is responsible for the depolarization phase?

Accepted Answer

Sodium ions ($$Na^+) $$entering the cell

Question 5

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

Accepted Answer

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

Question 6

Which of the following is a key difference between ionotropic and metabotropic receptors?

Accepted Answer

Ionotropic receptors directly open ion channels, while metabotropic receptors activate second messenger systems.

Question 7

A neuron is at rest with a membrane potential of $$-70\ 	ext{mV}. If $$the membrane becomes more negative, what process is occurring?

Accepted Answer

Hyperpolarization

Question 8

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

Accepted Answer

Schwann cells

Question 9

Which of the following best explains the 'all-or-none law' of action potentials?

Accepted Answer

Action potentials only occur if the membrane depolarization reaches a threshold; otherwise, no action potential is generated.

Question 10

Which process is primarily responsible for maintaining the resting membrane potential in neurons?

Accepted Answer

Active transport of $$Na^+$$ out and $$K^+ in $$via the sodium-potassium pump

Question 11

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

Accepted Answer

Inhibitory postsynaptic potential (IPSP)

Question 12

Which of the following is NOT a function of astrocytes in the central nervous system?

Accepted Answer

Forming myelin sheaths around axons

Question 13

Which of the following best describes the role of microglia in the nervous system?

Accepted Answer

Acting as phagocytes to remove dead neurons and respond to injury

Question 14

If a neuron receives both EPSPs and IPSPs at the same time, what determines whether it will fire an action potential?

Accepted Answer

The summation of all EPSPs and IPSPs at the axon hillock

Question 15

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

Accepted Answer

Depolarization, repolarization, hyperpolarization

Question 16

Which of the following best describes the function of terminal buttons in a neuron?

Accepted Answer

They release neurotransmitters into the synaptic cleft.

Question 17

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

Accepted Answer

The CNS consists of the brain and spinal cord, while the PNS consists of nerves and ganglia outside the CNS.

Question 18

Which of the following mechanisms helps terminate postsynaptic potentials?

Accepted Answer

Reuptake of neurotransmitter into the presynaptic neuron

Question 19

A patient receives an injection of blue dye into the bloodstream, but the dye does not enter the brain tissue. What does this observation indicate?

Accepted Answer

The presence of a selectively permeable blood-brain barrier

Question 20

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

Accepted Answer

It actively transports $$3\ Na^+$$ out and $$2\ K^+ in$$, using ATP.

Anatomy & Physiology: The Nervous System – Structure, Function, and Neural Communication

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