Human placental lactogen , relaxin , progesterone and estrogen are secreted from

Options

A. Placenta
B. corpus luteum
C. ovary
D. interstitial cells

Answer

To solve the question regarding the secretion of human placental lactogen, relaxin, progesterone, and estrogen, we will analyze the options provided and identify the correct source of these hormones.

### Step-by-Step Solution:

1. **Identify the Hormones**: The question mentions four hormones: human placental lactogen, relaxin, progesterone, and estrogen.

2. **Understand the Source of Each Hormone**:
- **Human Placental Lactogen (hPL)**: This hormone is primarily produced by the placenta during pregnancy. Its main role is to regulate maternal metabolism and promote fetal growth.
- **Relaxin**: This hormone is also secreted by the placenta, particularly during pregnancy, and helps in relaxing the uterine muscles and preparing the body for childbirth.
- **Progesterone**: While progesterone is produced by the corpus luteum in the early stages of pregnancy, during the later stages, it is primarily produced by the placenta.
- **Estrogen**: Similar to progesterone, estrogen is initially produced by the ovaries and corpus luteum, but during pregnancy, the placenta becomes a major source of estrogen.

3. **Evaluate the Options**:
- **Option 1: Placenta**: This is the correct answer as all four hormones are secreted by the placenta during pregnancy.
- **Option 2: Corpus Luteum**: This option is incorrect because while it does secrete progesterone and some estrogen, it does not produce hPL or relaxin.
- **Option 3: Ovary**: This option is also incorrect as the ovary primarily produces sex hormones and does not secrete hPL or relaxin.
- **Option 4: Interstitial Cells (Leydig Cells)**: This option is incorrect as Leydig cells primarily secrete testosterone, not the hormones mentioned in the question.

4. **Conclusion**: Based on the analysis, the correct answer is **Option 1: Placenta**, as it is the source of human placental lactogen, relaxin, progesterone, and estrogen during pregnancy.

### Final Answer:
**The hormones human placental lactogen, relaxin, progesterone, and estrogen are secreted from the placenta.**