Which neurotransmitter released by the parasympathetic nervous system can decrease heart rate?

Correct Answer: A

Rationale: The correct answer is A: Acetylcholine. Acetylcholine is released by the parasympathetic nervous system and acts on the heart to decrease heart rate. It binds to muscarinic receptors in the heart, leading to a decrease in heart rate through inhibition of the SA node. Norepinephrine (B) is released by the sympathetic nervous system and increases heart rate. Dopamine (C) and Serotonin (D) are not directly involved in regulating heart rate through the parasympathetic pathway.

Correct Answer: A

Rationale: The correct answer is A: Arrhythmia. An arrhythmia refers to an abnormal heartbeat rhythm, which can be too fast (tachycardia) or too slow (bradycardia). Arrhythmia encompasses both of these irregularities. Choice B, bradycardia, specifically refers to a slow heartbeat, while choice C, tachycardia, specifically refers to a fast heartbeat. Choice D, conductivity, is not directly related to the speed or rhythm of the heartbeat, making it an incorrect choice.

Correct Answer: A

Rationale: The correct answer is A: Hypertension. Hypertension refers to high blood pressure, where the force of blood against artery walls is too high. This condition can lead to serious health issues. Hypotension (B) is low blood pressure. Hyperlipidemia (C) is high levels of fats/lipids in the blood. Diabetes (D) is a condition related to blood sugar regulation, not blood pressure. Therefore, A is the correct answer as it specifically relates to the condition described in the question.

Correct Answer: A

Rationale: The correct answer is A: Chronic Obstructive Pulmonary Disease (COPD). COPD is a chronic lung disease characterized by chronic bronchitis and emphysema. Chronic bronchitis involves inflammation of the bronchial tubes, leading to excessive mucus production. Emphysema is the destruction of lung tissue, resulting in difficulty breathing. Pneumonia (B) is an acute infection of the lungs. Asthma (C) is a chronic condition characterized by airway inflammation and constriction. Tuberculosis (D) is an infectious disease caused by Mycobacterium tuberculosis affecting the lungs. Therefore, the correct answer is A as it specifically encompasses chronic bronchitis and emphysema, distinguishing it from the other options.

Correct Answer: A

Rationale: The correct answer is A: Oxygen therapy. This type of therapy delivers high concentrations of oxygen to the lungs to improve oxygen levels in the blood. Ventilator therapy (B) involves mechanical breathing assistance, not just oxygen delivery. Mechanical ventilation (C) is a broader term encompassing various types of mechanical respiratory support beyond just oxygen. CPAP therapy (D) is continuous positive airway pressure used to treat sleep apnea, not specifically for delivering high concentrations of oxygen. Therefore, oxygen therapy is the most direct and specific choice for delivering high concentrations of oxygen to the lungs.