Which of the following increases the calcium level in the blood ?

Options

A. Thyroxine
B. Calcitonin
C. Parathormone
D. Insulin

Answer

To determine which hormone increases the calcium level in the blood, we can analyze the functions of the hormones mentioned in the question. Here’s a step-by-step breakdown:

### Step 1: Identify the hormones listed
The question provides four options:
1. Thyroxine
2. Calcitonin
3. Parathormone
4. Insulin

### Step 2: Analyze the function of each hormone
- **Thyroxine**: This hormone is produced by the thyroid gland and primarily regulates metabolic activities and maintains the Basal Metabolic Rate (BMR). It does not have a direct role in increasing blood calcium levels.

- **Calcitonin**: Also produced by the thyroid gland, calcitonin helps to lower blood calcium levels. It achieves this by suppressing the activity of osteoclasts (cells that break down bone) and reducing the absorption of calcium from the intestine. Therefore, it does not increase calcium levels in the blood.

- **Parathormone (PTH)**: This hormone is secreted by the parathyroid glands and plays a crucial role in increasing blood calcium levels. It does this by enhancing the activity of osteoclasts, which increases the release of calcium from bones into the bloodstream, and by promoting the absorption of calcium from the intestines. Thus, parathormone works antagonistically to calcitonin.

- **Insulin**: This hormone is produced by the pancreas and is primarily involved in regulating blood glucose levels. It does not influence calcium levels in the blood.

### Step 3: Conclusion
From the analysis, it is clear that the hormone responsible for increasing calcium levels in the blood is **Parathormone**.

### Final Answer
The correct answer is **Parathormone**.

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