Correct Answer: A

Rationale: The correct answer is Cor pulmonale, a condition where the right ventricle of the heart fails due to increased pressure in the lungs, commonly caused by chronic lung diseases like COPD. Pulmonary embolism (choice B) is a blockage in one of the pulmonary arteries in the lungs, usually caused by a blood clot. Aortic stenosis (choice C) is a narrowing of the aortic valve opening that restricts blood flow from the left ventricle to the aorta. Hypertrophic cardiomyopathy (choice D) is a genetic condition where the heart muscle becomes abnormally thick, making it harder for the heart to pump blood.

Correct Answer: C

Rationale: The correct answer is the left ventricle. It receives oxygenated blood from the left atrium and pumps it to the rest of the body through the aorta. The left atrium receives oxygenated blood from the lungs, the right atrium receives deoxygenated blood from the body, and the right ventricle pumps deoxygenated blood to the lungs.

Correct Answer: A

Rationale: The correct answer is A, Pulse oximetry. Pulse oximetry is a non-invasive test that measures the oxygen saturation level in the blood, commonly used to monitor respiratory and cardiovascular health. Arterial blood gas (ABG) measures the levels of oxygen and carbon dioxide in the blood, providing more detailed information than pulse oximetry. Echocardiogram is an ultrasound test used to visualize the heart's structure and function, while a chest X-ray is used to visualize the structures in the chest, such as the heart, lungs, and bones.

Correct Answer: A

Rationale: The correct answer is A, Orthopnea. Orthopnea is a condition where a person finds it hard to breathe while lying flat and needs to use multiple pillows to sleep comfortably. This position helps relieve the discomfort by allowing better lung expansion. Choice B, Dyspnea, refers to difficulty breathing in general, not specifically related to lying flat. Choice C, Tachypnea, is rapid breathing and is not directly related to difficulty breathing while lying down. Choice D, Bradypnea, is slow breathing and does not describe the condition of having trouble breathing when lying flat.

Correct Answer: D

Rationale: The correct answer is D, Epinephrine. Epinephrine acts as a central vasoconstrictor and peripheral vasodilator. It increases heart rate and blood flow to muscles, helping to prepare the body for a 'fight or flight' response. Parasympathetic nervous system (choice A) does not cause vasoconstriction but rather vasodilation. The sympathetic nervous system (choice B) is primarily responsible for the fight or flight response, causing vasoconstriction. Dopamine (choice C) primarily acts as a neurotransmitter and hormone, not directly causing central vasoconstriction and peripheral vasodilation.