Question 1

Which of the following glial cells is primarily responsible for forming the myelin sheath in the central nervous system (CNS)?

Accepted Answer

Oligodendrocytes

Question 2

A patient with multiple sclerosis experiences demyelination in the CNS. Which cell type is most directly affected?

Accepted Answer

Oligodendrocytes

Question 3

Which of the following best describes the function of astrocytes in the brain?

Accepted Answer

They transfer nutrients to neurons and help maintain the blood-brain barrier.

Question 4

Which process is responsible for the movement of ions against their electrochemical gradient across the neuronal membrane?

Accepted Answer

Ion pumps

Question 5

A drug that blocks voltage-gated sodium channels would most likely have which effect on neuronal signaling?

Accepted Answer

It would prevent the initiation and propagation of action potentials.

Question 6

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

Accepted Answer

Ionotropic receptors open ion channels directly upon neurotransmitter binding, while metabotropic receptors use G proteins for slower, widespread effects.

Question 7

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

Accepted Answer

The absolute refractory period prevents reactivation of recently opened sodium channels.

Question 8

A neuron receives several excitatory postsynaptic potentials (EPSPs) and inhibitory postsynaptic potentials (IPSPs) at the same time. What determines whether an action potential will be generated?

Accepted Answer

The net effect of all EPSPs and IPSPs at the axon hillock crossing the threshold voltage

Question 9

Which of the following mechanisms is NOT involved in the termination of neurotransmitter action at a chemical synapse?

Accepted Answer

Continuous activation of postsynaptic receptors

Question 10

Which of the following best describes the role of the sodium-potassium pump in neurons?

Accepted Answer

It maintains the resting membrane potential by moving 3 Na+ ions out and 2 K+ ions in, using ATP.

Question 11

A patient is prescribed a selective serotonin reuptake inhibitor (SSRI) for depression. What is the primary effect of this medication at the synaptic level?

Accepted Answer

It blocks the reuptake of serotonin, increasing its concentration in the synaptic gap.

Question 12

Which of the following is TRUE regarding the propagation of action potentials in myelinated versus unmyelinated axons?

Accepted Answer

Action potentials are regenerated at every segment of unmyelinated axons, but only at the nodes of Ranvier in myelinated axons.

Question 13

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

Accepted Answer

They clean up brain debris and remove synapses, but dysregulation can contribute to neurodegenerative diseases.

Question 14

Which of the following events occurs during the absolute refractory period of an action potential?

Accepted Answer

Voltage-gated sodium channels are inactivated and cannot be reopened.

Question 15

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

Accepted Answer

They produce and regulate cerebrospinal fluid (CSF).

Question 16

A neuron receives multiple EPSPs and IPSPs in rapid succession at the same synapse. This process is known as:

Accepted Answer

Temporal summation

Question 17

Which of the following best explains why the resting membrane potential of a neuron is typically negative?

Accepted Answer

The sodium-potassium pump moves more positive ions out than in, and potassium leaks out through open channels.

Question 18

Which of the following is a consequence of phosphorylated tau protein in Alzheimer's disease?

Accepted Answer

Microtubules collapse, disrupting intracellular transport and leading to cell death.

Question 19

Which of the following is TRUE about the axon hillock?

Accepted Answer

It integrates and sums EPSPs and IPSPs to determine if an action potential will be initiated.

Question 20

Which of the following best describes the difference between motor neurons and sensory neurons?

Accepted Answer

Motor neurons transmit signals from the CNS to the periphery, while sensory neurons transmit signals from the periphery to the CNS.

Neurophysiology: Structure and Function of Neurons and Glia

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