Which one opposes parathormone ?

Options

A. ADH
B. Insulin
C. Thyroxine
D. Thyrocalcitonin.

Answer

**Step-by-Step Solution:**

1. **Understanding Parathormone**: Parathormone, also known as parathyroid hormone (PTH), is produced by the parathyroid glands. Its primary function is to regulate calcium levels in the blood.

2. **Function of Parathormone**: When blood calcium levels drop below the normal range, parathormone is released. It works to increase calcium levels in the blood by stimulating the release of calcium from bones, increasing calcium absorption in the intestines, and promoting calcium reabsorption in the kidneys.

3. **Identifying Opposing Hormones**: To find which hormone opposes parathormone, we need to look for a hormone that decreases blood calcium levels.

4. **Evaluating the Options**:
- **ADH (Antidiuretic Hormone)**: This hormone regulates water balance in the body and does not directly affect calcium levels.
- **Insulin**: This hormone regulates glucose levels in the blood and is not involved in calcium regulation.
- **Thyroxine**: This hormone regulates metabolism and energy levels but does not play a role in calcium regulation.
- **Thyrocalcitonin (Calcitonin)**: This hormone is secreted by the thyroid gland and functions to lower blood calcium levels by inhibiting bone resorption and promoting calcium deposition in bones.

5. **Conclusion**: Since parathormone increases blood calcium levels and thyrocalcitonin decreases blood calcium levels, thyrocalcitonin is the hormone that opposes parathormone.

6. **Final Answer**: The hormone that opposes parathormone is **thyrocalcitonin**.

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