Which of the following is not a part of circulatory system of human?

Options

A. Heart
B. Blood vessels
C. Sinuses
D. Blood

Answer

To solve the question "Which of the following is not a part of the circulatory system of humans?", we will analyze each option provided:

1. **Understanding the Components of the Circulatory System**:
- The circulatory system in humans primarily consists of three main components:
- **Heart**: This is the muscular organ that pumps blood throughout the body.
- **Blood Vessels**: These include arteries, veins, and capillaries that transport blood to and from the heart and throughout the body.
- **Blood**: This is the fluid that circulates in the blood vessels, carrying oxygen, nutrients, hormones, and waste products.

2. **Analyzing the Options**:
- **Option A: Heart**: This is a crucial part of the circulatory system. Therefore, it is not the correct answer.
- **Option B: Blood Vessels**: These are essential for the circulation of blood. Hence, this is also not the correct answer.
- **Option C: Sinuses**: Sinuses are cavities located in the skull that are part of the respiratory system, not the circulatory system. Therefore, this is the correct answer.
- **Option D: Blood**: As mentioned, blood is a fundamental component of the circulatory system. Thus, this is not the correct answer.

3. **Conclusion**:
- The option that is not a part of the circulatory system is **Sinuses**.

**Final Answer**: Sinuses

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