Deoxygenated blood is pumped by the heart in

Options

A. Reptiles
B. Birds
C. Mammals
D. Fishes

Answer

To answer the question "Deoxygenated blood is pumped by the heart in," we can follow these steps:

### Step 1: Understand the Types of Circulation
- The heart is responsible for pumping blood throughout the body, and different classes of animals have different types of circulatory systems.
- There are two main types of circulatory systems: single circulation and double circulation.

### Step 2: Identify the Circulatory System in Mammals
- In mammals, including humans, the circulatory system is characterized by double circulation. This means that blood passes through the heart twice during one complete circuit of the body.
- The heart has four chambers: two atria and two ventricles.

### Step 3: Trace the Path of Deoxygenated Blood
- Deoxygenated blood returns to the right side of the heart from the body through the superior and inferior vena cava.
- From the right atrium, the blood moves into the right ventricle and is then pumped into the pulmonary artery.

### Step 4: Understand the Role of the Pulmonary Circulation
- The pulmonary artery carries the deoxygenated blood to the lungs, where it receives oxygen and releases carbon dioxide.
- After the blood is oxygenated in the lungs, it returns to the left side of the heart via the pulmonary veins.

### Step 5: Conclusion
- Therefore, the correct answer to the question is that deoxygenated blood is pumped by the heart in mammals, specifically through the right side of the heart and into the pulmonary artery.

### Final Answer
Deoxygenated blood is pumped by the heart in mammals.

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