ATI RN
Cardiovascular System Assessment Questions Questions
Question 1 of 5
Which statement about erythrocytes is untrue?
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.
Question 2 of 5
On the heart, the impact of adrenaline is all of these except that
Correct Answer: C
Rationale: Adrenaline (epinephrine) increases heart rate (chronotropy), contraction force (inotropy), and oxygen demand via β-adrenergic stimulation. However, it increases myocardial irritability (risk of arrhythmias), not decreases it, making C the exception.
Question 3 of 5
The expression 'cardiac cycle' refers to:
Correct Answer: D
Rationale: The cardiac cycle is the sequence of mechanical and electrical events between one heartbeat and the next , including systole and diastole (~0.8s at 75 bpm). A is too broad, B is cardiac output, C is ECG-specific, and D is heart sound-specific, not the full cycle.
Question 4 of 5
The chamber that pumps oxygen rich blood to the body is the
Correct Answer: C
Rationale: The left ventricle (C) pumps oxygen-rich blood into the aorta for systemic circulation. The left atrium (A) fills the left ventricle, the right atrium (B) receives deoxygenated blood, and the right ventricle (D) pumps to the lungs.
Question 5 of 5
What is the natural pacemaker of the heart?
Correct Answer: B
Rationale: The SA node (B) is the natural pacemaker, initiating impulses at 60-100 bpm. The AV node (C) delays, AV bundle (A) conducts, and Purkinje fibers (D) spread the signal.