Blood platelets release

Options

A. Fibrinigens
B. Prothrombins
C. Hemoglobin
D. Thromboplastins

Answer

To answer the question "Blood platelets release," we need to analyze the options provided and understand the role of blood platelets in the coagulation process.

### Step-by-Step Solution:

1. **Understanding Blood Platelets**: Blood platelets, also known as thrombocytes, are small cell fragments in the blood that play a crucial role in hemostasis (the process of stopping bleeding).

2. **Coagulation Process**: When a blood vessel is injured, platelets aggregate at the site of injury, and they release various substances that are essential for blood clotting.

3. **Identifying the Options**:
- **Fibrinogens**: These are proteins that are converted into fibrin during the clotting process, but they are not released by platelets.
- **Prothrombins**: This is a precursor to thrombin, which is also not released by platelets.
- **Hemoglobin**: This is the protein in red blood cells that carries oxygen, and it is not related to platelets.
- **Thromboplastins**: This is another name for tissue factor or thromboplastin, which is released by platelets and plays a key role in the conversion of prothrombin to thrombin.

4. **Conclusion**: The correct answer is that blood platelets release **thromboplastins**. These thromboplastins facilitate the conversion of prothrombin into thrombin, which is crucial for the coagulation cascade.

### Final Answer:
Blood platelets release **thromboplastins**.

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