Micelles:

Correct Answer: D

Rationale: The correct answer is D because micelles are indeed clusters of cholesterol, fatty acids, bile salts, and 2 mono-glycerides formed in the small intestine during lipid digestion. This process aids in the absorption of lipids by increasing their surface area for enzymatic action. Choice A is incorrect as emulsified fat globules are not micelles, but rather the initial step in lipid digestion. Choice B is incorrect as pro-enzymes are not related to micelles. Choice C is incorrect as dead enterocytes are not involved in micelle formation.

Correct Answer: A

Rationale: The correct answer is A: resecting the constricted segment. In Hirschsprung's disease, there is a lack of ganglion cells in the distal bowel causing a functional obstruction. The treatment involves surgically removing the affected segment to allow normal bowel function. Resecting the dilated segment (choice B) is not effective as the issue lies in the constricted area. Colectomy and ileostomy (choice C) is an extreme measure and is usually reserved for severe cases. Avoiding surgical intervention (choice D) is not recommended as it can lead to complications and worsen the condition.

Correct Answer: B

Rationale: B: Carcinoma of the esophagus is difficult to cure due to local spread. Esophageal cancer often presents at advanced stages, making complete surgical resection challenging. Local spread to nearby structures like the trachea or blood vessels hinders curative treatment. This is supported by the fact that esophageal cancer has a poor prognosis, with a 5-year survival rate of around 20%. A: This is incorrect because esophageal carcinoma is often diagnosed at advanced stages when symptoms appear, making it less curable than early-stage cancers. C: Early widespread metastases are not a defining feature of esophageal carcinoma. Metastases typically occur at later stages of the disease. D: Esophageal carcinoma can be differentiated or undifferentiated, but this does not impact the difficulty in curing the cancer due to local spread.

Correct Answer: B

Rationale: The correct answer is B: Metabolic alkalosis. Vomiting causes loss of stomach acid (HCl), leading to an increase in blood pH and bicarbonate levels, resulting in metabolic alkalosis. Choice A is incorrect because vomiting does not lead to an increase in acid levels. Choices C and D are incorrect as they are related to respiratory disorders, not directly caused by vomiting. In summary, vomiting leads to metabolic alkalosis due to loss of stomach acid.

Correct Answer: A

Rationale: Rationale: Loperamide is an opioid receptor agonist that acts on the gut to slow down intestinal motility. This results in the slowed transit of intestinal contents, similar to how morphine works. This helps in alleviating diarrhea. Therefore, the correct answer is A. Choices B and C are incorrect because loperamide and morphine do not cause more rapid gastric emptying or increased colonic secretion of chloride ion. Choice D is incorrect as the correct answer has been explained.