The presence of large numbers of mitochondria in the tubule cells of nephrons suggests that the transport of materials into and out of tubule cells requires

Correct Answer: C

Rationale: The correct answer is C: energy. Mitochondria are responsible for producing energy in the form of ATP through cellular respiration, which is crucial for active transport processes in tubule cells of nephrons. Active transport requires energy to move molecules against their concentration gradient. Acids (choice A) are not directly related to the function of mitochondria in energy production. Pigments (choice B) are not involved in cellular energy production. Enzymes (choice D) facilitate reactions but do not directly provide the energy needed for transport processes. In summary, the presence of large numbers of mitochondria in tubule cells suggests the requirement of energy for material transport, making choice C the correct answer.

Correct Answer: B

Rationale: The correct answer is B: Relieved by eating. This is because food helps to neutralize stomach acid, providing temporary relief for duodenal ulcer pain. When the patient eats, the food acts as a buffer against the acid, reducing irritation and pain. The other choices are incorrect: A is not correct because pain after eating is typical of gastric ulcers, not duodenal ulcers. C is incorrect as duodenal ulcer pain is often related to meals due to increased acid secretion. D is incorrect as duodenal ulcer pain can occur at any time, not just at night.

Correct Answer: D

Rationale: The correct answer is D: lamina propria. The lamina propria is the connective tissue layer of a mucous membrane located beneath the epithelium. It provides support and nourishment to the epithelial cells. The other choices are incorrect because: A) the submucosa is a layer deep to the lamina propria, containing glands, blood vessels, and nerves; B) subcutaneous tissue is found beneath the skin, not within mucous membranes; C) the papillary layer is part of the dermis of the skin, not associated with mucous membranes.

Correct Answer: A

Rationale: The correct answer is A because in most regions of the GI tract, the smooth muscle fibers of the muscularis are arranged into inner circular and outer longitudinal layers. This arrangement allows for peristalsis, the coordinated contraction and relaxation of the muscles to move food along the digestive tract. The inner circular layer constricts the lumen, while the outer longitudinal layer shortens the tube. This arrangement is consistent throughout the GI tract to facilitate the smooth movement of food. Choice B is incorrect because the outer circular and inner longitudinal layers are not the typical arrangement in the GI tract. Choice C is incorrect because although there are circular and longitudinal layers, their relative position does not vary significantly from region to region. Choice D is incorrect as it describes a meshwork pattern which is not typical of the muscularis arrangement in the GI tract.

Correct Answer: D

Rationale: The correct answer is D: in the esophagus. Tonsils are lymphoid tissues located in the pharynx, soft palate, and posterior tongue, but not in the esophagus. The esophagus is a muscular tube that connects the throat to the stomach and does not contain tonsils. Tonsils are part of the immune system and help protect against infections. Therefore, the presence of tonsils in the esophagus would not be anatomically or functionally correct.