Where does the production of bile occur?

Correct Answer: B

Rationale: Step 1: Bile is produced by the liver. Step 2: The liver synthesizes bile which is then stored and concentrated in the gallbladder. Step 3: When needed for digestion, bile is released from the gallbladder into the small intestine. Step 4: Therefore, the correct answer is B (Liver). Summary: - A (Gallbladder): Stores and concentrates bile but does not produce it. - C (Pancreas): Produces digestive enzymes and bicarbonate, not bile. - D (Hepatic Ducts): Carry bile from the liver to the gallbladder, do not produce bile.

Correct Answer: D

Rationale: Step 1: Gastric juices contain hydrochloric acid, which helps in the breakdown of food and kills bacteria. Step 2: The combination of different enzymes in gastric juices works together to digest food effectively. Step 3: Therefore, the correct answer is D, as gastric juices in the stomach both kill bacteria and work together to digest food. Summary: - Choice A is incorrect because gastric juices do more than just killing bacteria. - Choice B is incorrect because gastric juices not only digest food but also kill bacteria. - Choice C is incorrect because gastric juices do more than just contain hydrochloric acid.

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.