ATI RN
Cardiovascular System Quiz Questions Questions
Question 1 of 5
If the AV node were forced to assume pacemaker activity, what would be the resulting pulse rate?
Correct Answer: D
Rationale: The AV node’s intrinsic rate is 40-60 bpm (D), slower than the SA node’s 60-100 bpm.
Question 2 of 5
The hormone produced in the heart that reduces the volume of blood
Correct Answer: C
Rationale: ANP (C), from the atria, reduces blood volume by promoting sodium and water excretion. ADH (A) and aldosterone (B) increase volume, renin (D) regulates pressure.
Question 3 of 5
A megakaryoblast will develop into
Correct Answer: C
Rationale: Megakaryoblasts form platelets (C) via fragmentation in bone marrow. RBCs (A), WBCs (B), and lymphocytes (D) arise from different precursors.
Question 4 of 5
Which of the following opposes the action of thromboxane A2 by inhibiting platelet adhesion and release?
Correct Answer: B
Rationale: Prostacyclin (B) from endothelium inhibits platelet aggregation, opposing thromboxane A2. Heparin (A) is an anticoagulant, fibrinogen (C) forms clots, thrombin (D) activates clotting.
Question 5 of 5
The average life span of an erythrocyte in the circulation is
Correct Answer: D
Rationale: Erythrocytes (D) live ~120 days, removed by spleen/liver.