A stenosis of the bicuspid heart valve might cause blood to back up into the:

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: 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.

Correct Answer: A

Rationale: Blood pressure is a measurement of the pressure exerted by the blood being pumped by the heart into the blood vessels, specifically measured in the larger arteries. Blood pressure may be influenced by the heart and intrathoracic pressure, but is accurately defined as pressure within the blood vessels. (Source: Document, Pretest Answer 5, p. 76)

Correct Answer: C

Rationale: Blood clotting requires calcium (cofactor), prothrombin (converted to thrombin), fibrinogen (forms fibrin), and platelets (form the plug and release clotting factors). Heparin inhibits clotting, and albumin/globulin/vitamin A are not directly involved.

Correct Answer: D

Rationale: Erythrocytes number ~25 trillion, are biconcave discs, and hemoglobin is ~15% of blood weight (close to one-sixth), but citric acid is not a key component (heme and globin are). This statement is untrue.