Which of the following inhalants is a gas anesthetic?

Correct Answer: C

Rationale: Certainly! Nitrous oxide is the correct answer as it is the only gas anesthetic listed. It is commonly used in dentistry and minor surgeries due to its anesthetic properties. Halothane, isoflurane, and desflurane are all liquid inhalants, not gas anesthetics. Nitrous oxide stands out as the only gas option among the choices.

Correct Answer: D

Rationale: The correct answer is D: Protamine sulfate. Protamine sulfate is an antagonist of heparin because it binds to heparin molecules, forming a stable complex that neutralizes the anticoagulant effects of heparin. This interaction helps to reverse the effects of heparin in cases of heparin overdose or when immediate cessation of anticoagulation is required. A: Aspirin is an antiplatelet agent that inhibits platelet aggregation by irreversibly inhibiting cyclooxygenase. It is not an antagonist of heparin. B: Dicumarol is a vitamin K antagonist that inhibits the synthesis of vitamin K-dependent clotting factors. It is not an antagonist of heparin. C: Dalteparin is a low-molecular-weight heparin that acts as an anticoagulant by inhibiting the activity of factor Xa. It is not an antagonist of heparin. In summary, Protamine sulfate

Correct Answer: A

Rationale: Step-by-step rationale for why A (Digoxin) is the correct answer: 1. Digoxin is a cardiac glycoside that slows conduction through the AV node, making it effective in controlling supraventricular tachycardias. 2. It increases the refractory period of the AV node, reducing the heart rate. 3. Digoxin is not a vasopressor like Dobutamine or Dopamine, which are used for different indications. 4. Amrinone is a phosphodiesterase inhibitor, primarily used in heart failure, not specifically for supraventricular tachycardias.

Correct Answer: D

Rationale: The correct answer is D: Nifedipine. Nifedipine is a calcium channel blocker that directly acts on vascular smooth muscle to cause vasodilation by inhibiting calcium influx. Labetalol and Clonidine are alpha and beta blockers, Enalapril is an ACE inhibitor, which all indirectly cause vasodilation. Therefore, Nifedipine is the only directly acting vasodilator among the choices.

Correct Answer: A

Rationale: The correct answer is A because hormones are indeed products of endocrine gland secretion. Endocrine glands release hormones directly into the bloodstream to regulate various physiological processes. Choice B is incorrect as hormones are not mediators of the inflammatory process. Choice C is wrong because hormones are not by-products of tissue metabolism but rather specific signaling molecules. Choice D is incorrect as hormones are not products of exocrine gland secretion but rather endocrine glands.