Correct Answer: A

Rationale: The correct answer is A, Pulmonary edema. Pulmonary edema is a condition where fluid accumulates in the air sacs of the lungs, causing breathing difficulty. Pleurisy (choice B) is inflammation of the pleura causing chest pain. Pleural effusion (choice C) is the buildup of excess fluid in the pleural space, the area between the layers of tissue that line the lungs and chest cavity. Pneumothorax (choice D) is the presence of air in the pleural space, which can cause a lung to collapse.

Correct Answer: A

Rationale: The correct answer is an echocardiogram. An echocardiogram utilizes high-frequency sound waves (ultrasound) to create images of the heart, enabling doctors to evaluate its structure, function, and detect any abnormalities. MRI (Choice B) uses magnetic fields and radio waves to produce detailed images of the body's structures. CT scan (Choice C) combines X-rays and computer technology to create cross-sectional images of the body. X-ray (Choice D) uses electromagnetic radiation to produce images of the internal structures of the body, but it is not the most suitable for assessing the heart's structure and function.

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: The correct answer is A: Muscle pain. Muscle pain can be a sign of rhabdomyolysis, a serious side effect of statins like atorvastatin. Rhabdomyolysis is a condition where muscle fibers break down rapidly and release their contents into the bloodstream, which can lead to kidney damage. Headache, nausea, and dizziness are not commonly associated with atorvastatin use and are less likely to indicate a serious adverse reaction compared to muscle pain.

Correct Answer: A

Rationale: Excitability is the correct term that describes the ability of cardiac cells to respond to an impulse by contracting. Excitability refers to the cell's ability to respond to stimuli and generate an action potential. Choice B, Contractility, is incorrect as it refers to the ability of cardiac cells to contract after receiving a stimulus, not the response to the impulse itself. Choice C, Rhythmicity, is incorrect as it pertains to the heart's ability to contract rhythmically without external stimulation. Choice D, Conductivity, is incorrect as it refers to the ability of cardiac cells to transmit an impulse from cell to cell, not the direct response to the impulse by contracting.