Which of the following is not a function of the large intestine?

Correct Answer: B

Rationale: The correct answer is B: Absorption of nutrients. The large intestine's main functions are absorption of water and formation of feces. Nutrient absorption primarily occurs in the small intestine, not the large intestine. Choice A is incorrect because the large intestine absorbs water to form solid waste. Choice C is incorrect because the large intestine is responsible for storing and eliminating feces. Choice D is incorrect as the large intestine does not absorb nutrients.

Correct Answer: A

Rationale: The correct answer is A: Cullen sign. Ecchymosis around the umbilicus indicates intra-abdominal bleeding. Cullen sign specifically refers to bruising around the umbilicus, which can be a sign of retroperitoneal bleeding. Rovsing sign is rebound tenderness in appendicitis. McBurney sign is tenderness at McBurney's point in appendicitis. Grey-Turner's sign is bruising on the flanks, indicating retroperitoneal or pancreatitis-related bleeding. Cullen sign is the most appropriate choice for ecchymosis around the umbilicus.

Correct Answer: B

Rationale: The correct answer is B: submucosa. The submucosa is the layer of the gastrointestinal tract that contains tough, fibrous connective tissue, providing support and elasticity. The mucosa (choice A) is the innermost layer responsible for absorption, not toughness. The muscle layer (choice C) is responsible for peristalsis and movement, not toughness. The serosa (choice D) is the outermost layer providing protection, not toughness. Therefore, choice B is the correct answer as it accurately describes the layer characterized by tough, fibrous connective tissue in the gastrointestinal tract.

Correct Answer: B

Rationale: The correct answer is B: lipids. Cholecystokinin (CCK) is released in response to the presence of lipids in the duodenum. When lipids are detected, CCK is secreted by the enteroendocrine cells in the small intestine. CCK plays a crucial role in the digestion and absorption of lipids by stimulating the release of bile from the gallbladder and pancreatic enzymes. Explanation for why the other choices are incorrect: A: Chyme is a mixture of partially digested food and gastric juices. While chyme may contain lipids, it is not the specific stimulus for CCK release. C: Protein stimulates the release of other hormones like gastrin and secretin, not CCK. D: Gastrin is a hormone that stimulates gastric acid secretion, not CCK release in response to lipids.

Correct Answer: B

Rationale: The correct answer is B: cystic. The common bile duct is formed by the merger of the hepatic duct from the liver and the cystic duct from the gallbladder. The cystic duct carries bile from the gallbladder to the common bile duct, which then transports bile to the small intestine. Choices A, C, and D are incorrect because the common bile duct is not formed by the merger of the common hepatic, pancreatic, or Santorini ducts. Each of these ducts serves a different function in the digestive system.