What is the primary function of the kidneys in acid-base balance?

Correct Answer: A

Rationale: The correct answer is A. The kidneys are crucial in maintaining acid-base balance by removing hydrogen ions to decrease acidity and retaining bicarbonate ions to increase alkalinity. Choice B is incorrect because the conversion of ammonia into urea is related to nitrogen waste excretion, not acid-base balance. Choice C is incorrect as aldosterone regulates sodium levels, not acid-base balance. Choice D is also incorrect as renin is involved in regulating blood pressure, not acid-base balance.

Correct Answer: B

Rationale: An allergic reaction is a common trigger for acute bronchospasm in asthma patients. When individuals with asthma come in contact with allergens like pollen, dust mites, or pet dander, it can lead to an allergic reaction that triggers bronchospasm. Infections, excessive exercise, and high altitudes can exacerbate asthma symptoms, but they are not the most common trigger for acute bronchospasm in asthma patients.

Correct Answer: B

Rationale: The correct answer is B, Diabetes insipidus. Diabetes insipidus is characterized by a lack of antidiuretic hormone (ADH), leading to excessive urination and thirst. Choice A, Diabetes mellitus, is a different condition characterized by high blood sugar levels. Choice C, Cushing's disease, is caused by prolonged exposure to high levels of cortisol. Choice D, Hyperthyroidism, involves an overactive thyroid gland producing excess thyroid hormones.

Correct Answer: B

Rationale: Hepatic encephalopathy is caused by increased ammonia levels in the bloodstream. Ammonia, a byproduct of protein metabolism normally processed by the liver, accumulates in the bloodstream when the liver is unable to function properly. This excess ammonia affects brain function, leading to symptoms of hepatic encephalopathy. Choices A, C, and D are incorrect because they do not directly relate to the pathophysiology of hepatic encephalopathy.

Correct Answer: A

Rationale: The correct answer is A: Dyspnea on exertion. COPD typically manifests with symptoms like dyspnea on exertion due to impaired lung function. This symptom is a result of the airways being obstructed and the lungs not being able to expel air effectively. Choices B and C are incorrect because in COPD, abnormal lung sounds such as wheezing, crackles, or diminished breath sounds are often heard upon auscultation, and arterial blood gases are usually abnormal, showing low oxygen levels and high carbon dioxide levels. Choice D is incorrect as COPD is more commonly diagnosed in individuals over 40 who have a history of smoking or exposure to lung irritants.