Which of the following hormones is not synthesised in Gl tract ?

Options

A. Gastrin
B. Renin
C. Secretin
D. Cholecystokinin

Answer

To determine which hormone is not synthesized in the gastrointestinal (GI) tract, we can follow these steps:

### Step-by-Step Solution:

1. **Understand the Question**: We need to identify a hormone that is not produced in the GI tract. The GI tract produces several hormones that are primarily involved in digestion.

2. **Review the Options**: The options provided are:
- Option 1: Gastrin
- Option 2: Renin
- Option 3: Secretin
- Option 4: Cholecystokinin (CCK)

3. **Analyze Each Option**:
- **Option 1: Gastrin**: This hormone is produced in the stomach and stimulates the secretion of gastric acid (HCl). Therefore, it is synthesized in the GI tract.
- **Option 2: Renin**: This hormone is secreted by the kidneys and plays a role in regulating blood pressure and fluid balance. It is not produced in the GI tract.
- **Option 3: Secretin**: This hormone is produced in the small intestine and helps regulate the pH of the small intestine by stimulating the secretion of bicarbonate from the pancreas. Thus, it is a GI hormone.
- **Option 4: Cholecystokinin (CCK)**: This hormone is also produced in the small intestine and is involved in digestion, particularly in stimulating the gallbladder to release bile. Hence, it is synthesized in the GI tract.

4. **Identify the Correct Answer**: After analyzing all options, we find that **Renin** (Option 2) is the only hormone listed that is not synthesized in the GI tract.

### Final Answer:
The hormone that is not synthesized in the GI tract is **Renin** (Option 2).

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