Question 1

Which layer of the heart is primarily responsible for its contractile function?

Accepted Answer

Myocardium

Question 2

A patient presents with a heart murmur due to turbulent blood flow. Which of the following is the most likely cause?

Accepted Answer

Valvular stenosis

Question 3

Which of the following correctly traces the pathway of a red blood cell through the heart, starting from the right atrium?

Accepted Answer

Right atrium → tricuspid valve → right ventricle → pulmonary valve → pulmonary trunk → lungs → left atrium → bicuspid valve → left ventricle → aortic valve → aorta

Question 4

Which of the following statements about cardiac muscle cells is TRUE?

Accepted Answer

They have intercalated discs with desmosomes and gap junctions

Question 5

The plateau phase of the cardiac contractile cell action potential is primarily due to:

Accepted Answer

Influx of slow calcium ions

Question 6

Which equation correctly represents cardiac output ($$CO) in $$terms of heart rate ($$HR) $$and stroke volume ($$SV$$)?

Accepted Answer

$$CO = HR 	imes SV$$

Question 7

During ventricular systole, which valves are open and which are closed?

Accepted Answer

AV valves closed, semilunar valves open

Question 8

Which of the following best explains the physiological significance of the absolute refractory period in cardiac muscle?

Accepted Answer

It prevents tetanic contractions, ensuring the heart can fill between beats

Question 9

Which structure is known as the pacemaker of the heart and why?

Accepted Answer

SA node, because it initiates sinus rhythm and sets the heart rate

Question 10

A patient with chronic hypertension is likely to experience which change in cardiac muscle cells?

Accepted Answer

Hypertrophy of cardiac muscle cells due to increased workload

Question 11

Which of the following best describes the Frank-Starling Law of the Heart?

Accepted Answer

Within physiological limits, the heart pumps whatever volume of blood it receives

Question 12

Which of the following is a direct effect of sympathetic nervous system stimulation on the heart?

Accepted Answer

Increased heart rate and contractility

Question 13

Which of the following events is responsible for the first heart sound (S1)?

Accepted Answer

Closure of AV valves

Question 14

Which of the following best describes the role of gap junctions in cardiac muscle?

Accepted Answer

They allow electrical coupling for synchronized contraction

Question 15

Which phase of the cardiac cycle is associated with the highest ventricular pressure?

Accepted Answer

Ventricular systole

Question 16

If a patient’s end diastolic volume ($$EDV) is 120 mL $$and end systolic volume ($$ESV) is 50 mL$$, what is their stroke volume ($$SV$$)?

Accepted Answer

$$SV = 120 - 50 = 70 mL$$

Question 17

Which of the following is TRUE regarding the coronary circulation?

Accepted Answer

Coronary arteries deliver blood most effectively when the heart is relaxed

Question 18

Which of the following best describes the effect of increased afterload on stroke volume?

Accepted Answer

Increased afterload decreases stroke volume

Question 19

Which of the following is a distinguishing feature of autorhythmic cardiac cells compared to contractile cardiac muscle cells?

Accepted Answer

Autorhythmic cells have pacemaker potentials that spontaneously depolarize

The Heart: Structure, Function, and Physiology (Topic 4.2, Chapter 18)

Guida di studio - Domande di pratica

Study guide - Flashcard