Which organ is by passed by Foetal Circulation `:-`

Options

A. Heart
B. Brain
C. Lung
D. Liver

Answer

**Step-by-Step Solution:**

1. **Understanding Fetal Circulation**: Fetal circulation is different from adult circulation. In the fetus, certain organs are not functional and do not perform their usual roles.

2. **Identifying Bypassed Organs**: In adults, the lungs are responsible for oxygenating blood. However, in a fetus, the lungs are not used for this purpose because the fetus receives oxygen and nutrients through the placenta from the mother.

3. **Role of the Foramen Ovale**: The foramen ovale is an opening between the right atrium and the left atrium of the heart. This allows blood to bypass the non-functional lungs by flowing directly from the right atrium to the left atrium.

4. **Conclusion**: Since the lungs are not functioning during fetal development and blood is bypassed from the right atrium to the left atrium through the foramen ovale, we conclude that the organ bypassed by fetal circulation is the lungs.

5. **Post-Birth Changes**: After birth, the pressure in the right atrium decreases, allowing the lungs to open and function, which leads to the closure of the foramen ovale.

**Final Answer**: The organ bypassed by fetal circulation is the **lungs**.

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