Testosterone is secreted by:

Options

A. Mast cells
B. Sertoli cells
C. Kupffer cells
D. Leydig's cells

Answer

**Step-by-Step Solution:**

1. **Identify the Hormone**: The question asks about the secretion of testosterone, which is a hormone primarily associated with male reproductive functions.

2. **Understand the Source**: Testosterone is secreted by specific cells in the male reproductive system. These cells are known as Leydig cells.

3. **Function of Leydig Cells**: Leydig cells are endocrine cells located in the testes. Their primary function is to produce testosterone, which plays a crucial role in the development of male secondary sexual characteristics and reproductive functions.

4. **Regulation of Testosterone Secretion**: The secretion of testosterone is regulated by signals from the anterior pituitary gland. The anterior pituitary receives signals from the hypothalamus, which triggers the Leydig cells to produce testosterone.

5. **Review Other Options**: In the context of the question, it is important to differentiate Leydig cells from other cell types mentioned:
- **Mast Cells**: Involved in allergic reactions and inflammation, not related to testosterone.
- **Sertoli Cells**: Support and nourish developing sperm but do not secrete testosterone.
- **Kupffer Cells**: Located in the liver and involved in the breakdown of red blood cells, unrelated to testosterone secretion.

6. **Conclusion**: The correct answer to the question is that testosterone is secreted by Leydig cells.

**Final Answer**: Testosterone is secreted by Leydig cells.

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