Which of the following hormones is secreted by implanted blastocyst, that acts on the corpus luteum in the ovary, stimulating the body to produce estrogens and progesterone to maintain the uterine lining

Options

A. Estrogen
B. HCG
C. Progesterone
D. Oxytocin

Explanation

To solve the question about which hormone is secreted by the implanted blastocyst that acts on the corpus luteum in the ovary, we can follow these steps:

### Step-by-Step Solution:

1. **Understand the Role of the Blastocyst**: The blastocyst is an early stage of embryonic development that implants into the uterine lining. Once implanted, it begins to secrete hormones.

2. **Identify the Hormone Secreted by the Blastocyst**: The hormone secreted by the implanted blastocyst is Human Chorionic Gonadotropin (HCG). This hormone is crucial during early pregnancy.

3. **Function of HCG**: HCG acts on the corpus luteum, which is a temporary endocrine structure in the ovaries. It stimulates the corpus luteum to continue producing hormones.

4. **Hormones Produced by the Corpus Luteum**: The corpus luteum produces estrogen and progesterone. These hormones are essential for maintaining the uterine lining, which is necessary for the implantation and sustenance of the embryo.

5. **Conclusion**: The correct answer to the question is HCG, as it is the hormone secreted by the implanted blastocyst that stimulates the corpus luteum to produce estrogen and progesterone, thereby maintaining the uterine lining.

### Final Answer:
The hormone secreted by the implanted blastocyst that acts on the corpus luteum in the ovary is Human Chorionic Gonadotropin (HCG).

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