Soluble inorganic and organic nutrient material, hormones, antibodies, against diptheria, smallpox, scarlet fever, measles etc. can pass from the mother to the foetus, so we can say that placenta act as a –

Options

A. Endocrine gland
B. Barrier
C. Ultra filter
D. All of above

Answer

**Step-by-Step Solution:**

1. **Understanding the Role of the Placenta**: The placenta is a vital organ that forms during pregnancy. It connects the developing fetus to the uterine wall, allowing for nutrient uptake, waste elimination, and gas exchange via the mother's blood supply.

2. **Nutrient Transfer**: The placenta facilitates the transfer of soluble inorganic and organic nutrients from the mother to the fetus. This includes essential nutrients like glucose, amino acids, and fatty acids that are crucial for fetal development.

3. **Hormone Production**: The placenta acts as a temporary endocrine gland. It produces hormones such as human chorionic gonadotropin (hCG), progesterone, and estrogen, which are essential for maintaining pregnancy and supporting fetal growth.

4. **Immune Function**: The placenta allows the transfer of antibodies from the mother to the fetus, providing passive immunity against various diseases, including diphtheria, smallpox, scarlet fever, and measles.

5. **Barrier Function**: The placenta also acts as a barrier, regulating the exchange of substances between the mother and fetus. It prevents harmful substances and pathogens from reaching the fetus while allowing beneficial nutrients and antibodies to pass through.

6. **Ultrafiltration**: The placenta can be thought of as functioning like an ultrafilter, selectively allowing certain substances to pass while blocking others, thus maintaining a suitable environment for the developing fetus.

7. **Conclusion**: Given these functions, we can conclude that the placenta acts as a temporary endocrine gland, a barrier, and an ultrafilter, making it a multifunctional organ essential for fetal development.

**Final Answer**: The placenta acts as a temporary endocrine gland, a barrier, and an ultrafilter.

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