Serotonin and Melatonin are hormones, secreted by

Options

A. Pancreas
B. Pineal body
C. Pituitary gland
D. Thymus.

Answer

**Step-by-Step Solution:**

1. **Identify the hormones in question:** The hormones mentioned are serotonin and melatonin.

2. **Understand the source of these hormones:** We need to determine which gland or organ secretes these hormones.

3. **Analyze the options provided:**
- **Pancreas:** This organ primarily produces insulin and glucagon, which are involved in glucose metabolism.
- **Pineal body:** This gland is known for synthesizing and secreting melatonin, which regulates sleep-wake cycles and responds to environmental light.
- **Pituitary gland:** This gland produces various hormones, including oxytocin and growth hormone, but not serotonin or melatonin.
- **Thymus:** This organ is involved in immune function and produces hormones like thymosine, but does not produce serotonin or melatonin.

4. **Determine the correct answer:** Since the pineal body is responsible for the synthesis and secretion of melatonin and serotonin is a precursor to melatonin, the correct answer is the pineal body.

5. **Conclusion:** Therefore, the hormones serotonin and melatonin are secreted by the pineal body.

**Final Answer:** Pineal body.

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