In open circulatory system blood pumped by heart passes in which of the following?

Options

A. Sinuses
B. Lymph nodes
C. Artery
D. Vein

Answer

**Step-by-Step Solution:**

1. **Understanding Open Circulatory System**: In an open circulatory system, the blood (or hemolymph) is not confined entirely within blood vessels. Instead, it flows freely through cavities in the body.

2. **Role of the Heart**: The heart pumps the hemolymph into the body, but instead of flowing through a network of veins and arteries as in a closed circulatory system, it is released into open spaces.

3. **Identification of Blood Flow Path**: In an open circulatory system, the blood does not travel through veins. Instead, it moves through sinuses, which are large spaces or cavities.

4. **Return to the Heart**: After circulating through the body, the hemolymph is collected and returned to the heart through a series of efferent sinuses.

5. **Conclusion**: Based on the understanding of how an open circulatory system functions, the correct answer to the question is that blood pumped by the heart passes through **sinuses**.

**Final Answer**: A) Sinuses

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