Question 1

Which of the following best describes the primary function of the sodium-potassium pump ($$\mathrm{Na^+/K^+}-$$ATPase) in the plasma membrane of animal cells?

Accepted Answer

It actively transports $$3\ \mathrm{Na^+}$$ out of the cell and $$2\ \mathrm{K^+}$$ into the cell, maintaining the resting membrane potential.

Question 2

A patient is experiencing muscle weakness and irregular heartbeats. Laboratory tests reveal low extracellular potassium levels. Which of the following best explains how this condition affects the resting membrane potential of neurons?

Accepted Answer

The resting membrane potential becomes more negative (hyperpolarized) because the potassium equilibrium potential shifts further from zero.

Question 3

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

Accepted Answer

Myelin insulates axons, increasing the speed of action potential conduction via saltatory conduction.

Question 4

During the cardiac cycle, which event is directly responsible for the first heart sound ($$S_1) $$heard with a stethoscope?

Accepted Answer

Closure of the atrioventricular (AV) valves at the beginning of ventricular systole.

Question 5

A person is exposed to a toxin that blocks voltage-gated calcium channels in the axon terminal of a motor neuron. Which of the following will most likely occur at the neuromuscular junction?

Accepted Answer

No acetylcholine will be released, preventing muscle contraction.

Question 6

Which of the following equations correctly represents the calculation of cardiac output ($$CO$$)?

Accepted Answer

$$CO = HR 	imes SV$$

Question 7

A patient with a mutation in the gene encoding for dystrophin is most likely to experience which of the following?

Accepted Answer

Progressive muscle weakness due to instability of the muscle cell membrane.

Question 8

Which of the following best explains why red blood cells placed in a hypotonic solution swell and may burst?

Accepted Answer

Water moves into the cell by osmosis because the intracellular solute concentration is higher than the extracellular fluid.

Question 9

Which of the following is the correct sequence of events during skeletal muscle contraction, starting from the arrival of an action potential at the neuromuscular junction?

Accepted Answer

Acetylcholine binds to receptors → Action potential travels down T-tubules → Release of calcium from the sarcoplasmic reticulum → Cross-bridge formation

Question 10

A 60-year-old patient is diagnosed with atherosclerosis, which narrows the arteries and increases peripheral resistance. According to the equation $$BP = CO 	imes TPR$$, what effect will this have on blood pressure ($$BP) if $$cardiac output ($$CO) $$remains constant?

Accepted Answer

Blood pressure will increase because total peripheral resistance ($$TPR) is $$higher.

Question 11

Which of the following best describes the function of astrocytes in the central nervous system?

Accepted Answer

They maintain the blood-brain barrier and regulate the extracellular environment.

Question 12

A patient is given a drug that inhibits acetylcholinesterase at the neuromuscular junction. What is the most likely effect on muscle contraction?

Accepted Answer

Muscle contraction will be prolonged due to increased acetylcholine in the synaptic cleft.

Question 13

Which of the following statements about the refractory period in neurons is correct?

Accepted Answer

The absolute refractory period occurs because voltage-gated sodium channels are inactivated.

Question 14

Which of the following best explains why the left ventricle has a thicker wall than the right ventricle?

Accepted Answer

The left ventricle pumps blood to the systemic circulation, which requires higher pressure to overcome greater resistance.

Question 15

A person is running a marathon. Which of the following physiological changes would you expect to occur in their skeletal muscle cells during intense exercise?

Accepted Answer

Increased oxygen delivery and increased production of ATP via aerobic respiration.

Question 16

Which of the following is the correct formula for calculating mean arterial pressure ($$MAP$$)?

Accepted Answer

$$MAP = \dfrac{1}{3} (SBP - DBP) + DBP$$

Question 17

Which of the following best describes the Frank-Starling law of the heart?

Accepted Answer

The greater the end-diastolic volume, the greater the force of contraction, up to a physiological limit.

Question 18

A patient is found to have a mutation that causes voltage-gated sodium channels to remain open longer than normal in neurons. Which of the following is the most likely consequence?

Accepted Answer

The neuron will have prolonged depolarization, increasing the risk of hyperexcitability and seizures.

Question 19

Which of the following best explains why calcium channel blockers are used to treat hypertension?

Accepted Answer

They decrease the force of cardiac muscle contraction and cause vasodilation, lowering blood pressure.

ANP College Study Guide: Cell Membranes, Nervous System, Muscle, and Cardiovascular Physiology

Study Guide - Practice Questions

Study Guide - Flashcards