Cardiovascular System Exam

Correct Answer: A

Rationale: The correct answer is A: Right atrium. The right atrium is the heart chamber that receives deoxygenated blood returning from the body via the superior and inferior vena cava. The blood enters the right atrium from the vena cava and then passes through the tricuspid valve into the right ventricle. Choices B, C, and D are incorrect because the left atrium receives oxygenated blood from the lungs, the right ventricle pumps blood to the lungs for oxygenation, and the left ventricle pumps oxygenated blood to the body.

Correct Answer: A

Rationale: Ventricular tachycardia is the correct answer. It is a condition characterized by the heart's electrical system malfunctioning, leading to very fast heartbeats originating from the ventricles. Ventricular tachycardia can be life-threatening as it may progress to ventricular fibrillation, causing cardiac arrest. Atrial fibrillation (choice B) involves rapid, irregular beating of the atria, not the ventricles. Supraventricular tachycardia (choice C) originates above the ventricles and does not involve ventricular malfunction. Bradycardia (choice D) is the opposite of tachycardia, characterized by an abnormally slow heart rate.

Correct Answer: A

Rationale: Paroxysmal nocturnal dyspnea is the correct answer. It is characterized by sudden episodes of severe shortness of breath during sleep, often waking the individual. Choice B, Sleep apnea, involves pauses in breathing during sleep but does not usually present with acute shortness of breath. Choice C, Orthopnea, refers to shortness of breath that occurs when lying flat and is relieved by sitting up. Choice D, Dyspnea, is a general term for difficult or labored breathing and does not specifically describe acute episodes at night.

Correct Answer: B

Rationale: The correct answer is B: Atrioventricular Valves. The atrioventricular (AV) valves, including the mitral valve and tricuspid valve, close during ventricular systole to prevent backflow of blood from the ventricles into the atria. They open during ventricular diastole to allow blood flow from the atria into the ventricles. Semilunar valves, choice A, are located at the exits of the ventricles and prevent backflow into the ventricles. The mitral valve and tricuspid valve, choices C and D, are specific types of AV valves.

Correct Answer: A

Rationale: The correct action for the nurse to take when a client on a beta blocker presents with a blood pressure of 88/58 mm Hg is to hold the beta blocker and notify the healthcare provider. Beta blockers can further decrease blood pressure, which is already low in this case. Administering the beta blocker as ordered (Choice B) would exacerbate the hypotension. Increasing the dose of the beta blocker (Choice C) would be inappropriate and unsafe given the low blood pressure. Continuing to monitor the client and reassessing in 30 minutes (Choice D) could lead to a delay in necessary intervention. Therefore, the priority is to hold the medication and seek guidance from the healthcare provider.