The seminal fluid coagulates on ejaculation due to

Options

A. Sodium contents from prostatic secretion
B. sodium contents from Cowper's glands
C. Calcium and fibrinogen contents from prostate and seminal vesicles secretions, respectively.
D. secretions of epididymis

Answer

To solve the question regarding why seminal fluid coagulates upon ejaculation, we can break down the information step by step:

### Step-by-Step Solution:

1. **Understanding Seminal Fluid**:
- Seminal fluid is the liquid that is ejaculated from the male reproductive system during copulation. It contains sperm and various other components that help in the fertilization process.

**Hint**: Remember that seminal fluid is essential for transporting sperm to the female reproductive tract.

2. **Components of Seminal Fluid**:
- Seminal fluid is composed of sperm and secretions from accessory glands such as the seminal vesicles, prostate gland, and bulbourethral glands. These secretions provide nutrients and a medium for sperm.

**Hint**: Identify the accessory glands involved in producing seminal fluid.

3. **Role of Accessory Glands**:
- The seminal vesicles secrete fructose and fibrinogen, while the prostate gland contributes calcium to the seminal fluid. These components play a crucial role in the properties of the fluid.

**Hint**: Focus on what each gland contributes to the seminal fluid.

4. **Coagulation Process**:
- Upon ejaculation, the seminal fluid begins to coagulate, which means it thickens and loses its fluidity. This process is primarily due to the presence of fibrinogen (which can convert to fibrin) and calcium.

**Hint**: Consider how coagulation is a common process in biological fluids and what components are responsible for it.

5. **Identifying the Correct Answer**:
- The coagulation of seminal fluid is specifically attributed to calcium from the prostate gland and fibrinogen from the seminal vesicles. Therefore, the correct answer to the question is that seminal fluid coagulates due to these two components.

**Hint**: Look for the specific substances mentioned in the options that relate to coagulation.

### Final Answer:
The seminal fluid coagulates on ejaculation due to calcium from the prostate gland and fibrinogen from the seminal vesicles.