Which of the following hormones is released by duodenum and acts on gall bladder?

Options

A. gastrin
B. secretin
C. cholecystokinin
D. GIP

Explanation

To solve the question, "Which of the following hormones is released by the duodenum and acts on the gall bladder?", we can follow these steps:

### Step 1: Identify the hormones listed in the options
The options provided are:
- Gastrin
- Secretin
- Cholecystokinin
- GIP (Gastric Inhibitory Peptide)

### Step 2: Understand the function of each hormone
- **Gastrin**: Primarily stimulates gastric acid secretion in the stomach and is not involved in gallbladder function.
- **Secretin**: Stimulates the pancreas to release bicarbonate and does not act on the gallbladder.
- **Cholecystokinin (CCK)**: Released by the duodenum in response to fats and proteins in the chyme. It stimulates the gallbladder to contract and release bile, which is essential for fat digestion.
- **GIP**: Primarily inhibits gastric motility and secretion, and does not have a direct action on the gallbladder.

### Step 3: Determine which hormone acts on the gallbladder
From the analysis, we can conclude that:
- Cholecystokinin is the only hormone among the options that is released by the duodenum and acts on the gallbladder to stimulate bile release.

### Conclusion
The correct answer is **Cholecystokinin**.

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