After implantation the part of the uterine endometrium lying between the developing fetus and the lumen of the uterus is called :

Options

A. decidua capsularis
B. decidua basalis
C. decidua reticularis
D. decidua parietalis

Answer

To answer the question regarding the part of the uterine endometrium that lies between the developing fetus and the lumen of the uterus after implantation, we can follow these steps:

### Step-by-Step Solution:

1. **Understanding the Uterine Structure**:
- The uterus has a lining called the endometrium, which plays a crucial role during pregnancy. After implantation, the endometrium undergoes changes to support the developing fetus.

2. **Identifying the Relevant Structures**:
- The uterine cavity is referred to as the lumen of the uterus.
- The developing fetus is embedded within the uterine endometrium and is surrounded by various membranes.

3. **Recognizing the Layers of the Endometrium**:
- After implantation, the endometrium differentiates into several layers:
- **Decidua basalis**: This layer is located at the base of the placenta.
- **Decidua parietalis**: This layer lines the rest of the uterine cavity.
- **Decidua capsularis**: This is the layer that directly lies between the developing fetus and the lumen of the uterus.

4. **Conclusion**:
- The specific part of the uterine endometrium that lies between the developing fetus and the lumen of the uterus is called the **decidua capsularis**.

### Final Answer:
The part of the uterine endometrium lying between the developing fetus and the lumen of the uterus after implantation is called the **decidua capsularis**.

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