The principal function for most surface epithelial cells in the small intestine (enterocytes) is:

Correct Answer: D

Rationale: The correct answer is D: absorbing nutrients. Enterocytes in the small intestine are primarily responsible for absorbing nutrients from digested food. They have specialized structures like microvilli to increase surface area for absorption. Choice A is incorrect because enterocytes do not secrete digestive enzymes; that is done by other cells in the small intestine. Choice B is incorrect because hormone secretion is mainly done by endocrine cells in the intestine. Choice C is incorrect because goblet cells are responsible for secreting mucus in the intestine, not enterocytes. In summary, enterocytes' main function is to absorb nutrients, not secrete enzymes, hormones, or mucus.

Correct Answer: D

Rationale: The intensely basophilic bodies in the epithelial lining of intestinal crypts represent condensed chromatin of mitotic figures. This is because during mitosis, chromatin condenses into visible bodies which are basophilic due to their high DNA content. These bodies are typically located towards the apical end of columnar cells where active cell division occurs. Explanation for the other choices: A: Mucus vesicles are typically seen as clear, not basophilic, in histological sections. B: Ribosomes are not typically visible as distinct bodies in H&E stained sections and are not basophilic. C: Chylomicrons are lipid droplets and are not basophilic bodies found in the epithelial lining.

Correct Answer: C

Rationale: The correct answer is C because a hepatic cord refers to a row of adjacent hepatocytes within a liver lobule, which are the functional units of the liver responsible for various metabolic functions. This structure is essential for liver function and is where processes like detoxification and metabolism occur. Choice A is incorrect because a hepatic cord is not another name for a branch of the portal vein. Choice B is incorrect because the tough connective tissue surrounding a portal triad is known as Glisson's capsule, not a hepatic cord. Choice D is incorrect as a hepatic cord is not a branch of the bile duct. Overall, understanding the anatomical structure and function of the liver is crucial in determining the correct answer.

Correct Answer: D

Rationale: Kupffer cells are specialized macrophages located in the liver sinusoids. They play a crucial role in immune responses and detoxification. The correct answer is D (macrophages) because Kupffer cells share similar functions, morphology, and origin with macrophages, both being phagocytic cells derived from monocytes. Lymphocytes (A) are a type of white blood cell involved in adaptive immune responses, hepatocytes (B) are liver parenchymal cells responsible for various metabolic functions, and neutrophils (C) are another type of white blood cell primarily involved in innate immune responses.

Correct Answer: D

Rationale: The correct answer is D: vitamin A. Fat-storing stellate cells, also known as Ito cells, are specialized cells found in the liver's space of Disse. These cells are primarily responsible for storing vitamin A. Vitamin A is crucial for various functions in the body, such as vision, immune function, and cell growth. Storing excess vitamin A in the liver helps maintain a steady supply for when needed. Now, let's analyze why the other choices are incorrect: A: Glycogen is stored in hepatocytes, not in fat-storing stellate cells. B: Glucose is stored in the form of glycogen in the liver, not in fat-storing stellate cells. C: Albumin is a protein synthesized by the liver but is not stored in fat-storing stellate cells.