ATI RN
Cardiovascular System Practice Questions Questions
Question 1 of 5
Cardiac muscle fibres are electrically connected to neighbouring fibres by
Correct Answer: C
Rationale: Gap junctions (C) electrically connect cardiac muscle fibers, allowing synchronized contraction. Desmosomes (A) provide mechanical strength, tight junctions (B) are rare, and interneurons (D) are neural.
Question 2 of 5
Valve that opens into the left ventricle
Correct Answer: B
Rationale: The mitral valve (B) opens into the left ventricle from the left atrium during diastole. Aortic (A) is outflow, tricuspid (C) and pulmonary (D) are right-sided.
Question 3 of 5
The relaxation of vascular muscles that decreases resistance to blood flow
Correct Answer: B
Rationale: Vasodilation (B) relaxes vascular smooth muscle, reducing resistance and increasing flow. Vasoconstriction (A) increases resistance, others (C, D) are unrelated.
Question 4 of 5
Which of the following plasma proteins plays a role in disease resistance?
Correct Answer: B
Rationale: Globulins (B), including antibodies, aid in disease resistance. Albumin (A) maintains osmotic pressure, fibrinogen (C) aids clotting, myoglobin (D) is in muscle.
Question 5 of 5
Which of the following hormones stimulates the development of megakaryoblasts?
Correct Answer: B
Rationale: Thrombopoietin (B) from liver/kidneys stimulates megakaryoblasts to form platelets. EPO (A) affects RBCs, NO (C) dilates vessels, hGH (D) promotes growth.