Pulmonary veins of Frog open into

Options

A. Sinus venosus
B. Right auricle
C. Left auricle
D. Truncus arteriosus

Answer

To answer the question about where the pulmonary veins of a frog open, we can follow these steps:

### Step-by-Step Solution:

1. **Understand the Function of Pulmonary Veins**:
- Pulmonary veins are responsible for carrying oxygenated blood from the lungs back to the heart. Unlike other veins, which carry deoxygenated blood, pulmonary veins are unique in that they transport oxygen-rich blood.

2. **Identify the Structure of the Frog's Heart**:
- The frog's heart has three main chambers: two atria (right and left) and one ventricle. The left atrium receives blood from the pulmonary veins.

3. **Locate the Source of Blood for the Pulmonary Veins**:
- The blood that enters the pulmonary veins comes from the lungs. In frogs, there are two lungs, and each lung contributes to the pulmonary veins.

4. **Determine the Destination of the Pulmonary Veins**:
- The pulmonary veins carry the oxygenated blood from the lungs directly to the left atrium (also called the left auricle) of the heart.

5. **Conclude the Answer**:
- Therefore, the pulmonary veins of the frog open into the left auricle (or left atrium) of the heart.

### Final Answer:
The pulmonary veins of the frog open into the left auricle (or left atrium).

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