Umbilical cord helps in the transport of substances to and from the embryo. Which among these is not a function of the umbilical cord:

Options

A. Serves as a blood source for the foetus.
B. Supplies nutrients and oxygen to the de veloping fetus.
C. Transfer waste products and deoxygenated blood away from the Fetus to the maternal circulation.
D. Helps in regulation of blood flow from foetal heart to foetal brain.

Explanation

To determine which among the given options is not a function of the umbilical cord, we can analyze the functions of the umbilical cord step by step.

### Step-by-Step Solution:

1. **Understanding the Umbilical Cord**: The umbilical cord is a vital structure that connects the developing fetus to the placenta. It serves as a conduit for the exchange of substances between the mother and the fetus.

2. **Identifying Functions**:
- **Blood Source**: The umbilical cord contains blood vessels that carry oxygenated blood and nutrients from the placenta to the fetus. This is indeed one of its primary functions.
- **Nutrient and Oxygen Supply**: The umbilical cord facilitates the transfer of essential nutrients and oxygen to the developing fetus from the maternal blood supply. This is also a confirmed function.
- **Waste Removal**: The umbilical cord is responsible for transporting waste products and deoxygenated blood from the fetus back to the placenta, where these waste products can be disposed of by the mother’s body. This is another correct function.
- **Regulation of Blood Flow**: The regulation of blood flow from the fetal heart to the fetal brain is primarily managed by the fetal circulatory system and not directly by the umbilical cord. Therefore, this is not a function of the umbilical cord.

3. **Conclusion**: After analyzing the functions, we can conclude that the option stating "regulation of blood flow from the fetal heart to the fetal brain" is not a function of the umbilical cord.

### Final Answer:
The correct answer is option 4: **Regulation of blood flow from the fetal heart to the fetal brain**.

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