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 determine which of the following is not a part of the circulatory system of humans, we can follow these steps:

### Step 1: Identify the Components of the Circulatory System
The circulatory system primarily consists of the following components:
- **Heart**: The central organ that pumps blood throughout the body.
- **Blood Vessels**: This includes arteries, veins, and capillaries that transport blood.
- **Blood**: The fluid that carries oxygen, nutrients, and waste products.

### Step 2: Analyze the Options
Now, we need to analyze the options given in the question. Common components of the circulatory system include the heart, blood vessels, and blood.

### Step 3: Identify the Non-Component
From the analysis, we can identify that:
- **Sinuses**: These are small pockets found in the skull, particularly around the nose and eyes, and are involved in producing mucus to trap foreign substances. They do not play a role in the circulatory system.

### Step 4: Conclusion
Based on the information gathered, we can conclude that **Sinuses** are not a part of the human circulatory system.

### Final Answer
The correct answer is **Sinuses**.

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