The circulatory pattern in which blood pumped by the heart passed through large vessels into open spaces or body cavities (sinuses) is

Options

A. Open circulatory system
B. Closedcirculatory system
C. incomplete circulatory system
D. Mixed circulatory system

Explanation

To solve the question regarding the circulatory pattern where blood pumped by the heart passes through large vessels into open spaces or body cavities (sinuses), we can follow these steps:

### Step-by-Step Solution:

1. **Understanding the Question**: The question asks for a specific type of circulatory system where blood moves from the heart into large vessels and then into open spaces or cavities.

2. **Identifying Circulatory Systems**: There are two main types of circulatory systems in animals: open and closed circulatory systems.
- In a **closed circulatory system**, blood is contained within vessels and does not enter open cavities.
- In an **open circulatory system**, blood (or hemolymph) is not confined to vessels and can flow freely into open spaces or cavities.

3. **Defining Open Circulatory System**: In an open circulatory system, the heart pumps blood into large vessels, which then lead to open spaces (called sinuses) where the blood bathes the organs directly. This is characteristic of many invertebrates, such as insects and some mollusks.

4. **Conclusion**: Based on the definitions and characteristics of the circulatory systems, the correct answer to the question is that the circulatory pattern described is an **open circulatory system**.

### Final Answer:
The circulatory pattern in which blood pumped by the heart passes through large vessels into open spaces or body cavities (sinuses) is an **open circulatory system**.

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