Alpha methyl dopa can produce:

Correct Answer: D

Rationale: Step 1: Alpha methyl dopa is a centrally acting antihypertensive medication. Step 2: It is a prodrug that is converted to alpha-methyl norepinephrine in the brain. Step 3: This metabolite stimulates alpha2 receptors in the brain, leading to decreased sympathetic outflow. Step 4: Decreased sympathetic outflow results in decreased peripheral vascular resistance and ultimately decreases blood pressure. Summary: Option D is correct because alpha methyl dopa decreases blood pressure by acting centrally on alpha2 receptors. Options A, B, and C are incorrect as alpha methyl dopa does not inhibit decarboxylase enzyme, increase renin, or stimulate alpha2 receptors centrally.

Correct Answer: D

Rationale: The correct answer is D: All of the above. Adrenaline is not given orally because: A) It is inactivated in the gut mucosa due to enzymatic breakdown, B) Local vasoconstriction inhibits absorption into the bloodstream, and C) It is rapidly inactivated in circulation by enzymes like catechol-O-methyltransferase and monoamine oxidase. Therefore, administering adrenaline orally would result in poor absorption and rapid degradation, making it ineffective.

Correct Answer: C

Rationale: Correct Answer: C Rationale: 1. Phenylephrine is a vasoconstrictor that raises blood pressure. 2. Increased blood pressure activates the baroreceptor reflex. 3. Baroreceptor reflex detects elevated blood pressure and sends signals to the brain. 4. The brain then signals the heart to slow down, thus normalizing the rapid heart rate in PSVT. Summary: A: Blocking beta-receptors would have the opposite effect, as beta-blockers slow down the heart rate. B: Stimulating norepinephrine release would increase heart rate, not slow it down. D: ACh esterase is involved in the breakdown of acetylcholine, not relevant to the mechanism of action of phenylephrine in PSVT.

Correct Answer: A

Rationale: Rationale: Atropine is the correct answer as it is an anticholinergic agent like propantheline, both inhibiting acetylcholine activity. This action reduces gastric acid secretion, aiding in peptic ulcer treatment. Neostigmine (B) increases acetylcholine activity, opposite to propantheline's effect. Propranolol (C) is a beta-blocker, not directly affecting gastric acid secretion. Phentolamine (D) is an alpha-blocker, also not related to reducing gastric acid secretion.

Correct Answer: B

Rationale: The correct answer is B: Only some bacteria will be killed by some antibiotics. Antibiotic resistance refers to the ability of bacteria to survive and grow despite the presence of an antibiotic. This occurs when bacteria evolve and develop mechanisms to defend against antibiotics. It is not accurate to say that no bacteria will be killed by any antibiotic (choice A) as some bacteria may still be susceptible to certain antibiotics. Antibiotics are not effective against viruses, so choice C and D are incorrect. In summary, antibiotic resistance specifically pertains to bacteria developing the ability to survive some antibiotics, making choice B the correct answer.