Which of the following is an accessory organ of digestion?

Correct Answer: A

Rationale: The correct answer is A: pancreas. The pancreas is an accessory organ of digestion because it produces digestive enzymes that help break down carbohydrates, fats, and proteins in the small intestine. It also secretes bicarbonate to neutralize stomach acid. The esophagus (B) is a part of the digestive tract but not an accessory organ. The stomach (C) and small intestine (D) are primary organs of digestion, not accessory organs.

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: C

Rationale: The correct answer is C: Cholecystokinin. Cholecystokinin is a hormone released by the small intestine in response to the presence of fats in the duodenum. It stimulates the gallbladder to contract and release bile into the small intestine to aid in the digestion and absorption of fats. Secretin (A) stimulates the pancreas to release bicarbonate to neutralize acidic chyme. Insulin (B) regulates blood sugar levels, not bile release. Gastrin (D) stimulates the release of gastric acid in the stomach, not bile.

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.