What is the stimulus for cholecystokinin release?

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: Correct Answer: B: intrinsic factor Rationale: 1. Intrinsic factor is essential for the absorption of vitamin B12 in the ileum. 2. Parietal cells secrete intrinsic factor in the stomach. 3. Without intrinsic factor, vitamin B12 cannot be absorbed, leading to pernicious anemia. Summary of Incorrect Choices: A: Hydrochloric acid is also secreted by parietal cells but is not directly involved in vitamin B12 absorption. C: Pepsinogen is a precursor to pepsin, which is involved in protein digestion, not vitamin B12 absorption. D: Mucus protects the stomach lining and does not play a role in vitamin B12 absorption.

Correct Answer: D

Rationale: The correct answer is D: pellagra. Pellagra is caused by a deficiency of nicotinic acid (niacin), which is a type of vitamin B3. Nicotinic acid is essential for the metabolism of carbohydrates and fats. Symptoms of pellagra include dermatitis, diarrhea, dementia, and eventually death if left untreated. Rationale: 1. Anaemia (Choice A) is not caused by a deficiency of nicotinic acid. 2. Osteomalacia (Choice B) is caused by a deficiency of vitamin D, not nicotinic acid. 3. Xerophthalmia (Choice C) is caused by a deficiency of vitamin A, not nicotinic acid. In summary, pellagra is the correct answer because it directly relates to the deficiency of nicotinic acid, while the other choices are caused by deficiencies of different vitamins.

Correct Answer: C

Rationale: The correct answer is C: Chronic blood loss. In ulcerative colitis, inflammation and ulcers in the colon can lead to chronic blood loss, resulting in anemia due to decreased red blood cell production. The inflamed colon may bleed continuously or intermittently, leading to a gradual decrease in hemoglobin levels. Dietary iron restrictions (choice A) may contribute to anemia, but chronic blood loss is the primary factor in this case. Intestinal malabsorption syndrome (choice B) may affect nutrient absorption but is not the main cause of anemia in this scenario. Intestinal parasites (choice D) can cause anemia through blood loss or nutrient depletion, but in this case, chronic blood loss from colitis is the most likely culprit.

Correct Answer: B

Rationale: The correct answer is B: Measure abdominal girth. In a possible bowel obstruction, measuring abdominal girth is crucial to monitor for signs of bowel distension, which can indicate worsening obstruction. This intervention helps in assessing the progression of the condition and can guide further management decisions. Obtaining daily weights (A) may be important for fluid balance but is not as immediate in this situation. Keeping strict intake and output (C) and encouraging fluid intake (D) are important but not the priority when addressing a possible bowel obstruction.