Which of the following secretes the antidiuretic hormone?

Correct Answer: B

Rationale: The correct answer is B: Pituitary gland. The antidiuretic hormone (ADH), also known as vasopressin, is produced and secreted by the pituitary gland. This hormone helps regulate water balance in the body by increasing water reabsorption in the kidneys. The other choices, A: Lungs, C: Liver, and D: Pineal gland, do not secrete ADH. Lungs are responsible for gas exchange, the liver performs various metabolic functions, and the pineal gland regulates sleep-wake cycles through melatonin secretion. Therefore, the pituitary gland is the only gland among the options that secretes the antidiuretic hormone.

Correct Answer: A

Rationale: The correct answer is A: Isoniazid. Isoniazid inhibits the synthesis of mycolic acid, a crucial component of mycobacterial cell walls. If used alone, resistance can develop rapidly due to its specific mechanism of action. Rifampicin (B) acts on RNA polymerase, not mycolic acid synthesis. Pyrazinamide (C) targets mycobacteria in acidic environments, not mycolic acid. Ethambutol (D) inhibits arabinosyltransferase, not mycolic acid synthesis.

Correct Answer: C

Rationale: Step-by-step rationale: 1. Minocycline is known to cause vestibular toxicity due to its lipophilicity and ability to accumulate in inner ear structures. 2. Vestibular toxicity can manifest as dizziness, vertigo, and imbalance. 3. Doxycycline, oxytetracycline, and demeclocycline are less likely to cause vestibular toxicity. 4. Doxycycline is commonly used and well-tolerated, oxytetracycline has a different side effect profile, and demeclocycline is primarily associated with nephrotoxicity. Summary: Choice C (Minocycline) is correct due to its propensity for causing vestibular toxicity. Choices A, B, and D are incorrect as they are less likely to cause this specific adverse effect.

Correct Answer: C

Rationale: The correct answer is Cefotaxime (C) because it is a third-generation cephalosporin with excellent penetration into the cerebrospinal fluid, making it effective against bacterial meningitis pathogens. Cefotaxime covers a broad spectrum of bacteria commonly causing meningitis, including Streptococcus pneumoniae and Neisseria meningitidis. A: Cefuroxime (A) is not the best choice as it has limited activity against some of the common pathogens causing meningitis. B: Cephalexin (B) is a first-generation cephalosporin with poor central nervous system penetration and limited activity against meningitis pathogens. D: Cefdinir (D) is a third-generation cephalosporin but is not the preferred choice for treating bacterial meningitis due to its inferior CNS penetration compared to cefotaxime.

Correct Answer: A

Rationale: The correct answer is A: Griseofulvin. Griseofulvin is the drug of choice for ringworm infection because it specifically targets the fungus that causes ringworm. It works by inhibiting fungal cell division, leading to the destruction of the fungus. Amphotericin B is an antifungal medication used for systemic fungal infections, not for ringworm. Nystatin is used to treat fungal infections of the skin, mouth, and intestines, but it is not the first-line treatment for ringworm. Neomycin is an antibiotic used to treat bacterial infections, not fungal infections like ringworm. Therefore, Griseofulvin is the most appropriate choice for treating ringworm.