Question 1

Which of the following best describes the primary function of Schwann cells in the peripheral nervous system?

Accepted Answer

They wrap around a single axon to form myelin sheaths, increasing the speed of action potential conduction.

Question 2

A patient with multiple sclerosis experiences slowed neural conduction. Which of the following best explains this phenomenon?

Accepted Answer

Demyelination increases ion leakage, reducing the speed of saltatory conduction along axons.

Question 3

Which equation correctly represents the Nernst equation for calculating the equilibrium potential of potassium ($$K^+) $$across a neuronal membrane?

Accepted Answer

$$E_K = \frac{RT}{zF} \ln \left( \frac{[K^+]_{out}}{[K^+]_{in}} \right)$$

Question 4

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

Accepted Answer

Voltage-gated $$Na^+$$ channels open, allowing $$Na^+ to $$enter the cell and depolarize the membrane.

Question 5

Which of the following best explains why action potentials are unidirectional along an axon?

Accepted Answer

The refractory period prevents the backward propagation of action potentials.

Question 6

A neuron receives two excitatory postsynaptic potentials (EPSPs) in rapid succession at the same synapse. What is this process called, and what is its effect?

Accepted Answer

Temporal summation; it can bring the membrane potential to threshold if the EPSPs are close enough in time.

Question 7

Which of the following is a correct statement about graded potentials?

Accepted Answer

They can be depolarizing or hyperpolarizing and their amplitude varies with stimulus strength.

Question 8

Which neurotransmitter and receptor pair is correctly matched for skeletal muscle contraction?

Accepted Answer

Acetylcholine and nicotinic receptor

Question 9

A patient presents with hyperkalemia (elevated extracellular $$K^+). $$What effect does this have on the resting membrane potential and neuronal excitability?

Accepted Answer

Resting membrane potential becomes less negative, making neurons more likely to fire action potentials.

Question 10

Which of the following best describes the role of calcium ions ($$Ca^{2+}) at $$the synaptic terminal?

Accepted Answer

$$Ca^{2+}$$ triggers exocytosis of synaptic vesicles containing neurotransmitters.

Question 11

Which of the following is a function of the hypothalamus?

Accepted Answer

Regulates body temperature and controls food intake.

Question 12

Which of the following statements about the blood-brain barrier is correct?

Accepted Answer

It is formed by tight junctions between endothelial cells and astrocyte foot processes, restricting movement of many substances.

Question 13

Which of the following best describes the difference between white matter and gray matter in the central nervous system?

Accepted Answer

White matter contains myelinated axons; gray matter contains neuron cell bodies, dendrites, and axon terminals.

Question 14

A person is unable to understand spoken or written language but can speak fluently, although their speech lacks meaning. Which brain area is most likely damaged?

Accepted Answer

Wernicke's area

Question 15

Which of the following best explains the effect of insulin on plasma glucose levels after a meal?

Accepted Answer

Insulin decreases plasma glucose by promoting glucose uptake and storage in cells.

Question 16

Which of the following metabolic pathways is dominant during the fasted state?

Accepted Answer

Glycogenolysis and gluconeogenesis

Question 17

A patient with type 1 diabetes mellitus is likely to experience which of the following symptoms after ingesting a carbohydrate-rich meal?

Accepted Answer

Hyperglycemia, polyuria, and glucosuria due to lack of insulin

Question 18

Which of the following is a characteristic of REM sleep?

Accepted Answer

Brain activity inhibits motor neurons to skeletal muscle, resulting in paralysis.

Question 19

Which of the following best describes the process of long-term potentiation (LTP) in learning and memory?

Accepted Answer

LTP is a long-lasting increase in synaptic strength following high-frequency stimulation.

Neurons: Cellular and Network Properties & The Central Nervous System

Study Guide - Practice Questions

Study Guide - Flashcards