What does the pancreas secrete to aid in digestion?

Correct Answer: C

Rationale: The correct answer is C: digestive enzymes. The pancreas secretes digestive enzymes such as amylase, lipase, and protease to break down carbohydrates, fats, and proteins in the small intestine. Insulin (choice A) is a hormone that regulates blood sugar levels, not aid in digestion. Gastric acid (choice B) is produced by the stomach, not the pancreas. Bile (choice D) is produced by the liver and stored in the gallbladder to aid in fat digestion, not directly secreted by the pancreas for digestion.

Correct Answer: D

Rationale: The correct answer is D: The small intestine has segmentation contractions. This is because segmentation contractions are responsible for mixing and moving chyme (partially digested food) along the small intestine, allowing for optimal nutrient absorption. This process helps maximize the contact between chyme and the intestinal walls, facilitating absorption. A: Incorrect. The small intestine does not store food for several hours; instead, it continuously processes and absorbs nutrients. B: Incorrect. While the small intestine plays a crucial role in digestion and absorption, the main source of digestive enzymes is the pancreas. C: Incorrect. Haustrae are found in the large intestine, not the small intestine. They aid in the absorption of water and electrolytes.

Correct Answer: B

Rationale: Bile does not contain potassium (K) as it is not a component of bile. The correct answer is B. Alkaline phosphatase is present in bile and aids in digestion. Cholesterol is also found in bile. CCK (Cholecystokinin) is a hormone released by the small intestine to stimulate bile release. Potassium is not a part of the composition of bile.

Correct Answer: A

Rationale: The correct answer is A. Peristalsis involves coordinated waves of muscle contractions that propel food forward. However, peristalsis can also involve backward movements to help with mixing and digestion. Therefore, the statement that peristalsis only involves forward movements is incorrect. Segmentation involves mixing and breaking down food through contractions that occur in non-unidirectional patterns. Peristalsis can be found in the esophagus, stomach, and intestines, while segmentation is mainly present in the small intestine. Therefore, choices B, C, and D are incorrect based on the explanations provided.

Correct Answer: C

Rationale: Infarction of the bowel may be caused by a volvulus, where the bowel twists on its mesentery, leading to compromised blood flow. Mesenteric artery thrombosis can also cause bowel infarction by obstructing blood supply. Therefore, the correct answer is C (both). Choices A and B are incorrect because each of them individually can cause bowel infarction.