Which functions as gastric hormone

Options

A. Secretin
B. Serotonin
C. Amphetamine
D. None of the above.

Answer

To answer the question "Which functions as a gastric hormone?", we will follow these steps:

### Step-by-Step Solution:

1. **Understanding Gastric Hormones**: Gastric hormones are substances that regulate various functions in the stomach, including digestion and motility. They play a crucial role in the digestive process.

2. **Identifying the Options**: The question likely provides multiple options. In this case, we will focus on the options given in the transcript, which include secretin, serotonin, and amphetamine.

3. **Analyzing Secretin**: Secretin is identified as a hormone that is secreted by the duodenum (the first part of the small intestine). It was the first hormone discovered and has significant roles in digestion.

4. **Functions of Secretin**: Secretin acts on several target organs:
- **Liver**: Stimulates the secretion of bile.
- **Pancreas**: Promotes the release of bicarbonates to neutralize stomach acid, making the intestinal environment alkaline.
- **Stomach**: Decreases gastric secretion and motility, which helps regulate the digestive process.

5. **Evaluating Other Options**:
- **Serotonin**: This is primarily a neurotransmitter and is not classified as a gastric hormone.
- **Amphetamine**: This is a drug and does not have a role as a gastric hormone.

6. **Conclusion**: Based on the analysis, the correct answer is secretin, as it functions as a gastric hormone by regulating various digestive processes.

### Final Answer:
The hormone that functions as a gastric hormone is **Secretin**.

---