Contracting of gall bladder is carried by-

Options

A. citric acid + acetyl Co-A
B. gastrin
C. cholecystokinin
D. none of these

Answer

To determine what carries out the contraction of the gallbladder, we can analyze the options provided:

1. **Citric Acid and Acetyl Coenzyme A**:
- These substances are primarily involved in the Krebs cycle, which is a part of cellular respiration and occurs after digestion. They do not play a role in the contraction of the gallbladder.
- **Conclusion**: This option is incorrect.

2. **Gastrin**:
- Gastrin is a hormone secreted by the stomach that primarily stimulates the secretion of gastric acid (HCl) and promotes mucous secretion. It does not have a direct role in gallbladder contraction.
- **Conclusion**: This option is incorrect.

3. **Cholecystokinin (CCK)**:
- Cholecystokinin is a hormone produced by the CCK cells in the duodenum. Its primary functions include stimulating the gallbladder to contract and release bile, as well as stimulating the pancreas to release digestive enzymes. Therefore, CCK is directly responsible for the contraction of the gallbladder.
- **Conclusion**: This option is correct.

4. **None of these**:
- Since we have identified that cholecystokinin is responsible for gallbladder contraction, this option is also incorrect.

**Final Answer**: The contraction of the gallbladder is carried out by **cholecystokinin**.

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