The lower respiratory tract is consist except

Correct Answer: A

Rationale: The correct answer is A: Nose. The lower respiratory tract includes the trachea, bronchioles, and lungs, but not the nose. The nose is a part of the upper respiratory tract, responsible for filtering, humidifying, and warming inhaled air. The trachea and bronchioles are part of the lower respiratory tract, involved in the passage of air into the lungs for gas exchange. Therefore, the nose does not belong to the lower respiratory tract, making it the correct answer. Choices B and C (bronchioles and trachea) are incorrect as they are part of the lower respiratory tract. Choice D is incorrect because both the bronchioles and trachea are part of the lower respiratory tract.

Correct Answer: d

Rationale: Rationale: Carbonic anhydrase in the gastrointestinal tract catalyzes the conversion of carbon dioxide and water to bicarbonate and protons. This reaction helps maintain pH balance in the gut. Starch breakdown is not directly associated with carbonic anhydrase. Protein digestion is primarily carried out by proteases, and lipid absorption involves enzymes like lipase. These functions are not directly related to carbonic anhydrase in the gastrointestinal tract. Thus, the correct answer is D: Starch breakdown.

Correct Answer: C

Rationale: The correct answer is C: Crackles. Crackles indicate left-sided heart failure due to fluid accumulation in the lungs. This occurs when the left side of the heart is unable to efficiently pump blood, leading to fluid backing up into the lungs. Weight gain (A) may be a general sign of heart failure but is not specific to left-sided failure. Ascites (B) is more indicative of right-sided heart failure, where fluid accumulates in the abdomen. Jugular vein distention (D) is a sign of right-sided heart failure, where blood backs up into the systemic circulation causing jugular vein distention.

Correct Answer: C

Rationale: Rationale for Correct Answer (C): - Increase of lung volume results in decrease, not increase, in resistance in extra alveolar vessels due to increased recruitment of capillaries. - This is known as distension recruitment, which helps reduce resistance in extra alveolar vessels. - Increased lung volume also helps to distribute blood flow more evenly in the lungs, reducing resistance. - Therefore, statement C is false. Summary of Incorrect Choices: A: True - increase in pulmonary arterial pressure generally causes a fall in pulmonary resistance due to vessel dilation. B: True - pulmonary resistance is indeed lower than systemic circulation resistance due to shorter pulmonary vascular bed. D: True - acetylcholine causes bronchiole smooth muscle contraction, not relaxation.

Correct Answer: D

Rationale: The correct answer is D because in obstructive lung diseases like COPD, FEV1 is reduced compared to FVC due to air trapping. This is a characteristic feature of obstruction. A: Incorrect, normal FEV1/FVC ratio is around 80-85%. B: Incorrect, in lung fibrosis, both FEV1 and FVC are reduced but the reduction in FVC is typically more prominent. C: Incorrect, while expiratory effort affects FEV1 maneuver, it is not the sole determinant.