Excessive amount of calcium is regulated by

Options

A. Thyroxine
B. Calcitonin
C. Epinephrine
D. Progesterone

Answer

To determine which hormone regulates excessive amounts of calcium in the body, we can follow these steps:

### Step 1: Identify the Condition
We need to understand that the question is about the regulation of excessive calcium levels in the blood.

**Hint:** Think about what happens when calcium levels rise in the bloodstream.

### Step 2: Recall the Role of the Thyroid Gland
The thyroid gland has cells known as parafollicular cells (or C cells) that are involved in calcium regulation.

**Hint:** Consider which hormones are produced by the thyroid gland and their functions.

### Step 3: Identify the Hormone Released
When calcium levels in the blood increase, the parafollicular cells release a specific hormone to lower these levels. This hormone is known as calcitonin.

**Hint:** Remember that calcitonin is specifically associated with lowering blood calcium levels.

### Step 4: Understand the Function of Calcitonin
Calcitonin is a polypeptide hormone made up of 32 amino acids. Its primary function is to decrease the concentration of calcium in the blood by inhibiting osteoclast activity (cells that break down bone) and promoting calcium deposition in bones.

**Hint:** Think about how the body maintains homeostasis and which hormones are involved in balancing calcium levels.

### Step 5: Evaluate the Options
The options given were thyroxine, calcitonin, epinephrine, and progesterone. Based on our understanding, calcitonin is the hormone that specifically regulates excessive calcium levels.

**Hint:** Eliminate the other options by considering their primary functions in the body.

### Conclusion
The hormone that regulates excessive amounts of calcium in the body is **calcitonin**.

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