Embryonic urinary bladder is

Options

A. Amnion
B. Chorion
C. Allantois
D. All

Answer

**Step-by-Step Solution:**

1. **Understanding the Embryonic Structures**: In human embryonic development, several membranes and structures are formed, including the amnion, chorion, allantois, and yolk sac. Each of these has specific functions.

2. **Identifying the Urinary Bladder**: The embryonic urinary bladder is primarily associated with the allantois. The allantois is a sac-like structure that arises from the embryonic gut (alimentary canal) and plays a role in the storage of excretory products.

3. **Function of the Allantois**: The allantois serves as a temporary storage site for urine and other excretory substances in the embryo. It is important for waste management before the formation of the functional urinary system.

4. **Distinguishing Between Membranes**:
- The **amnion** is a membrane that surrounds the embryo and contains amniotic fluid, providing cushioning and protection.
- The **chorion** contributes to the formation of the placenta and provides additional protection.
- The **yolk sac** is involved in nutrient transfer early in development but is not directly related to the urinary system.

5. **Conclusion**: Therefore, the embryonic urinary bladder is represented by the allantois, which is responsible for storing temporary urine in the embryo.

**Final Answer**: The embryonic urinary bladder is the allantois.

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