which component of pharynx received the Eustachian tube

Correct Answer: C

Rationale: The correct answer is C: Nasopharynx. The Eustachian tube connects the middle ear to the nasopharynx, allowing for pressure equalization. The oropharynx (A) and laryngopharynx (B) do not directly receive the Eustachian tube. Choice D is incorrect as the Eustachian tube does connect to a specific part of the pharynx.

Correct Answer: A

Rationale: Carbonic anhydrase catalyzes the conversion of carbon dioxide and water to bicarbonate and hydrogen ions in the kidney. Inhibiting carbonic anhydrase reduces bicarbonate reabsorption, leading to increased excretion of bicarbonate in the urine. Therefore, the correct answer is A. Incorrect choices: B: Inhibiting carbonic anhydrase would decrease bicarbonate reabsorption, resulting in increased excretion, not decreased. C: Inhibition of carbonic anhydrase does have an effect on bicarbonate excretion. D: Inhibiting carbonic anhydrase would not increase reabsorption but rather decrease it, leading to increased excretion.

Correct Answer: D

Rationale: The correct answer is D: Milk. Milk is a high sodium food and can contribute significantly to a patient's daily sodium intake. For a patient on a 2000-mg sodium diet, it is crucial to limit high sodium foods like milk to prevent fluid retention and worsening of heart failure symptoms. Other choices (A, B, C) are lower in sodium compared to milk. Chicken, fresh spinach, and eggs are generally good protein sources with lower sodium content and can be included in moderation in a 2000-mg sodium diet for a heart failure patient.

Correct Answer: D

Rationale: The correct answer is D: Molecular weight of gas. Diffusion rate is inversely proportional to the square root of the molecular weight of the gas. This means that as the molecular weight increases, the diffusion rate decreases. This is because heavier molecules move more slowly and have a harder time diffusing through a medium. Surface area for diffusion, concentration gradient, and solubility of gas all directly affect diffusion rate. Increasing the surface area for diffusion allows for more space for molecules to diffuse, a steeper concentration gradient increases the rate of diffusion, and higher solubility of gas in a medium enhances the diffusion rate.

Correct Answer: C

Rationale: The correct answer is C because in the upright lung, the ventilation-perfusion ratio is higher at the top due to gravity causing increased perfusion at the bases. This results in a mismatch between ventilation and perfusion, leading to a higher V/Q ratio at the top. Choices A and B are incorrect because ventilation is actually greater at the bases due to the effect of gravity, leading to higher ventilation there. Choice D is incorrect because PO2 is higher at the apex of the lung due to decreased perfusion but not at the bases.