Secretin and cholecystokinin are digestive hormones. These are secreted by
(a) oesophagus
(b) ileum
(c) duodenum
(d) pyloric stomach

Options

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

Explanation

To determine where secretin and cholecystokinin are secreted, we can follow these steps:

### Step-by-Step Solution:

1. **Understanding the Hormones**:
- Secretin and cholecystokinin are both digestive hormones that play crucial roles in digestion.

2. **Identifying the Source of Secretin**:
- Secretin is secreted by the intestinal wall, specifically in response to acidic conditions in the duodenum. It helps regulate the pH of the intestine by stimulating the pancreas to release bicarbonate.

3. **Identifying the Source of Cholecystokinin**:
- Cholecystokinin is also secreted by the cells in the duodenum. It is released in response to the presence of fats and proteins in the chyme, stimulating the gallbladder to release bile and the pancreas to secrete digestive enzymes.

4. **Conclusion**:
- Both hormones are secreted from the duodenum, which is the first part of the small intestine.

5. **Choosing the Correct Option**:
- Among the options provided:
- (a) Oesophagus
- (b) Ileum
- (c) Duodenum
- (d) Pyloric stomach
- The correct answer is **(c) Duodenum**.

### Final Answer:
Secretin and cholecystokinin are secreted by the **duodenum** (option c).

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