ATI RN
Cardiovascular System Questions and Answers Quizlet Questions
Question 1 of 5
The sinoatrial node is situated in the wall of the:
Correct Answer: A
Rationale: The sinoatrial (SA) node, the heart’s primary pacemaker, is located in the upper wall of the right atrium near the entrance of the superior vena cava. It initiates the electrical impulses that regulate the heartbeat.
Question 2 of 5
In the brain, the endothelial cells of the capillary walls are more tightly fused than those in other body regions. This fact underlies the operation of the:
Correct Answer: C
Rationale: The blood-brain barrier relies on tightly fused endothelial cells (tight junctions) in brain capillaries, restricting passage of substances and protecting the CNS, aided by astrocytes but defined by this structure.
Question 3 of 5
A client is admitted with an occlusion (blockage) of the circumflex artery. When discussing the diagnosis with the client and family, the nurse would explain that this vessel is a branch of the:
Correct Answer: B
Rationale: The circumflex artery is a branch of the left coronary artery, which originates from the aorta. It supplies the left atrium and ventricle. Pulmonary veins and arteries relate to lung circulation, and the superior vena cava is a vein, not an artery.
Question 4 of 5
The intrinsic factor necessary for the complete maturation of red cells is derived from:
Correct Answer: D
Rationale: Intrinsic factor, produced by the stomach mucosa, is required for vitamin B₁₂ absorption in the ileum, essential for red blood cell maturation. Bone marrow produces RBCs, the liver stores B₁₂, and B₆ aids hemoglobin synthesis but isn’t intrinsic factor.
Question 5 of 5
Immunoglobulins of class IgA are produced by plasma cells and:
Correct Answer: C
Rationale: IgA, found in mucosal secretions (e.g., saliva, tears), protects the GI, urogenital, and respiratory tracts against pathogens. IgM and IgG fight blood infections, and IgE is linked to allergies.