A patient who underwent a percutaneous, transluminal coronary angioplasty four weeks ago has a subsequent ejection fraction of 30%. The patient returns for a follow-up visit. Examination reveals lungs that are clear on auscultation and slight pedal edema. The patient reports a 5 lb (2.27 kg) weight gain over the past two days. The cardiac-vascular nurse's initial action is to:

Correct Answer: C

Rationale: A 5 lb weight gain in two days with an ejection fraction of 30% (indicating heart failure) and pedal edema suggests fluid retention, a potential emergency. Notifying the physician is urgent for intervention, outweighing documentation (A), compliance checks (B), or scan review (D).

Correct Answer: D

Rationale: The cardiovascular system serves multiple essential functions. It transports oxygen and nutrients to cells through the blood (Choice A), removes carbon dioxide and metabolic waste products via venous return and exhalation (Choice B), and helps regulate body temperature by adjusting blood flow to the skin (Choice C). Since all these roles are accurate and collectively describe the system’s purpose, the correct answer is 'All of the above' (Choice D).

Correct Answer: C

Rationale: The bicuspid (mitral) valve is between the left atrium and left ventricle. Stenosis (narrowing) of this valve impedes blood flow from the left atrium to the left ventricle, causing blood to back up into the left atrium and subsequently into the pulmonary circuit (lungs), potentially leading to pulmonary congestion.

Correct Answer: B

Rationale: During ventricular contraction (systole), most but not all blood is ejected (ejection fraction is typically 50-70%). Some blood remains in the ventricles (end-systolic volume), and properly functioning AV valves prevent backflow into the atria.

Correct Answer: A

Rationale: The vasa vasorum are small blood vessels nourishing the walls of larger arteries and veins, located in the tunica adventitia (and sometimes tunica media), as these walls are too thick for diffusion alone.