Cardiovascular System Exam

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: Automaticity is the correct answer because it refers to the inherent ability of cardiac cells to generate electrical impulses without the need for external stimulation. Contractility (Choice B) is the ability of the heart muscle to contract and generate force, not related to electrical impulse generation. Conductivity (Choice C) refers to the ability of cardiac cells to transmit electrical impulses from cell to cell, not the spontaneous generation of impulses. Refractoriness (Choice D) is the period during which the cardiac cells are recovering and not able to respond to a new stimulus, not the spontaneous generation of impulses.

Correct Answer: A

Rationale: Pneumonia is the correct answer because it is an acute respiratory infection that inflames the alveoli in one or both lungs, leading to the accumulation of fluid or pus. This condition presents with symptoms like cough, fever, and difficulty breathing. Bronchitis is the inflammation of the bronchial tubes, not the alveoli. Tuberculosis is a bacterial infection that primarily affects the lungs but does not always result in alveolar inflammation. Asthma is a chronic respiratory condition characterized by airway inflammation and narrowing, not alveolar inflammation.

Correct Answer: A

Rationale: In this scenario, the nurse's priority action should be to hold the digoxin and notify the healthcare provider. A heart rate of 48 bpm is low, and digoxin, being a medication that can further decrease the heart rate, should be withheld. Administering the digoxin as ordered (Choice B) would not be appropriate in this situation as it can exacerbate bradycardia. Atropine (Choice C) is not the initial treatment for this scenario; holding the digoxin is the first action. Increasing the dose of digoxin (Choice D) would be contraindicated due to the client's bradycardia. Therefore, the correct action is to hold the digoxin and inform the healthcare provider for further guidance.

Correct Answer: A

Rationale: The correct answer is A, Coronary artery bypass graft (CABG). This surgical procedure involves grafting a blood vessel to bypass a blocked coronary artery, improving blood flow to the heart muscle. Choice B, Valve replacement, is a procedure to replace a damaged heart valve and is not directly related to bypassing blocked arteries. Choice C, Stent placement, involves inserting a mesh tube to keep blocked arteries open and is different from grafting a blood vessel. Choice D, Angioplasty, is a procedure to widen narrowed or blocked arteries, typically using a balloon catheter, and does not involve grafting a blood vessel.