Question 1

Which of the following best describes the role of the DHP receptor during skeletal muscle contraction?

Accepted Answer

It acts as a voltage sensor that triggers the opening of ryanodine receptors, allowing $$Ca^{2+}$$ release from the sarcoplasmic reticulum.

Question 2

A patient is experiencing muscle fatigue after prolonged exercise. Which of the following is the most likely cause of muscle fatigue at the cellular level?

Accepted Answer

Accumulation of inorganic phosphate ($$P_i) $$and depletion of glycogen stores in muscle fibers.

Question 3

Which of the following best explains the difference between isotonic and isometric muscle contractions?

Accepted Answer

Isotonic contractions result in muscle length change, while isometric contractions generate tension without changing muscle length.

Question 4

During the cardiac cycle, which event immediately follows the closure of the atrioventricular (AV) valves?

Accepted Answer

Isovolumic contraction of the ventricles

Question 5

Which of the following equations correctly calculates mean arterial pressure (MAP)?

Accepted Answer

$$MAP = Diastolic\ Pressure + \frac{1}{3}(Systolic\ Pressure - Diastolic\ Pressure)$$

Question 6

A person stands up quickly from a lying position and feels dizzy. Which cardiovascular reflex is primarily responsible for compensating for the sudden drop in blood pressure?

Accepted Answer

Baroreceptor reflex

Question 7

Which of the following best describes the Starling's law of the heart?

Accepted Answer

The greater the end-diastolic volume (EDV), the greater the force of ventricular contraction.

Question 8

Which of the following is true regarding the phases of the action potential in myocardial contractile cells?

Accepted Answer

The plateau phase is maintained by the influx of $$Ca^{2+}$$ ions through L-type calcium channels.

Question 9

Which of the following best describes the function of intercalated discs in cardiac muscle?

Accepted Answer

They allow rapid transmission of electrical signals and mechanical connection between cardiac cells.

Question 10

A patient has a blood pressure of 120/80 mmHg. What is their pulse pressure?

Accepted Answer

$$Pulse\ Pressure = Systolic\ Pressure - Diastolic\ Pressure = 120 - 80 = 40\ mmHg$$

Question 11

Which of the following is the correct sequence of events in the sliding filament theory of muscle contraction?

Accepted Answer

Cross-bridge formation, power stroke, detachment, cocking of myosin head

Question 12

Which of the following best describes the difference between smooth and skeletal muscle contraction?

Accepted Answer

Smooth muscle contraction is regulated by $$Ca^{2+}$$ binding to calmodulin, while skeletal muscle contraction is regulated by $$Ca^{2+}$$ binding to troponin.

Question 13

Which of the following is the correct formula for cardiac output (CO)?

Accepted Answer

$$CO = Heart\ Rate 	imes Stroke\ Volume$$

Question 14

Which of the following statements about the electrical conduction system of the heart is correct?

Accepted Answer

The sinoatrial (SA) node acts as the pacemaker of the heart, initiating each heartbeat.

Question 15

Which of the following best describes the effect of increased peripheral resistance on blood pressure, assuming cardiac output remains constant?

Accepted Answer

Blood pressure increases as peripheral resistance increases.

Question 16

Which of the following is a correct description of the events during isovolumic contraction of ventricular systole?

Accepted Answer

Ventricular pressure rises rapidly, all heart valves are closed, and no blood is ejected.

Question 17

Which of the following best explains why the refractory period in cardiac muscle is longer than in skeletal muscle?

Accepted Answer

The plateau phase of the cardiac action potential prolongs depolarization, preventing tetanus.

Question 18

Which of the following is a correct statement about the relationship between blood flow ($$F$$), pressure difference ($$\Delta P$$), and resistance ($$R$$)?

Accepted Answer

$$F = \frac{\Delta P}{R}$$

Question 19

Which of the following is a correct description of the crossed extensor reflex?

Accepted Answer

It is a polysynaptic reflex that helps maintain balance by extending the opposite limb when one limb withdraws from a painful stimulus.

Muscle and Cardiovascular Physiology: Study Guide (Chapters 12–15)

Study Guide - Practice Questions

Study Guide - Flashcards