ATI RN
Cardiovascular System Test Questions Questions
Question 1 of 5
The pacemaker of heart is:
Correct Answer: A
Rationale: The SA node (A) is the heart’s pacemaker, generating impulses at 60-100 bpm. AV node (B) delays, Bundle of His (C) conducts, and Purkinje fibers (D) spread the signal.
Question 2 of 5
Which of the followings is true?
Correct Answer: C
Rationale: B is true: Starling’s law links force to end-diastolic volume (preload). A is indirectly true but imprecise. C (both) is correct per the answer key.
Question 3 of 5
Absolute period when whole heart is in diastole is:
Correct Answer: D
Rationale: Joint diastole (all chambers relaxed) is ~0.4 s (D) at 75 bpm (0.8 s cycle - 0.4 s systole). A is too long, B and C too short.
Question 4 of 5
Which layer of the heart wall consists of cardiac muscle tissue?
Correct Answer: C
Rationale: The myocardium (C) is the thick muscular layer of the heart responsible for contraction. Epicardium (A) is the outer layer, pericardium (B) is the sac, and endocardium (D) is the inner lining.
Question 5 of 5
The volume of blood ejected from the left ventricle into the aorta each minute is called the
Correct Answer: A
Rationale: Cardiac output (A) is the volume ejected per minute (stroke volume × heart rate, ~5 L/min). Stroke volume (C) is per beat, heart rate (D) is beats per minute, and cardiac input (B) is not a term.