Secretin and cholecystokinin are secreted by

Options

A. oesophagus
B. ileum
C. duodenum
D. pyloric stomach

Explanation

**Step-by-Step Solution:**

1. **Identify the Hormones**: The question asks about secretin and cholecystokinin (CCK), which are both important hormones involved in digestion.

2. **Location of Secretion**: Secretin and cholecystokinin are secreted by the walls of the small intestine, specifically in the upper part known as the duodenum.

3. **Function of Secretin**: Secretin is a hormone that regulates gastric acid secretion and helps maintain the pH level in the duodenum. It is released in response to acidic chyme entering the duodenum from the stomach.

4. **Function of Cholecystokinin**: Cholecystokinin (CCK) stimulates the release of digestive enzymes from the pancreas and promotes the emptying of bile from the gallbladder into the small intestine, aiding in the digestion of fats.

5. **Conclusion**: Both secretin and cholecystokinin are secreted by the duodenum, making option C the correct answer.

**Final Answer**: Secretin and cholecystokinin are secreted by the duodenum.

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