ATI RN
Cardiovascular System Test Questions Questions
Question 1 of 5
Identify the hormone(s) that will decrease blood volume and thus blood pressure.
Correct Answer: C
Rationale: ANH (C) decreases blood volume and BP by promoting sodium/water loss and vasodilation. ADH and aldosterone (A, B, D) increase volume.
Question 2 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 3 of 5
Which of the following has single layer of endothelial structure?
Correct Answer: C
Rationale: Capillaries (C) consist of a single endothelial layer for exchange. Arteries (A) and veins (B) have multiple layers (tunicae), and lymphatics (D) have thin walls but valves.
Question 4 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 5 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.