Beta HCG is secreted by –
**Core Concept**
Beta Human Chorionic Gonadotropin (β-hCG) is a hormone produced during pregnancy, crucial for maintaining the corpus luteum and supporting embryonic development. It is a glycoprotein composed of an alpha subunit and a beta subunit.
**Why the Correct Answer is Right**
β-hCG is primarily secreted by the placenta, specifically the syncytiotrophoblast cells. These cells produce β-hCG to stimulate the corpus luteum, ensuring continued production of progesterone, essential for maintaining pregnancy. The hormone also plays a role in fetal development and has been used as a marker for pregnancy and certain types of cancer.
**Why Each Wrong Option is Incorrect**
**Option A:** This option is incorrect because β-hCG is not primarily secreted by the ovaries. Although the ovaries produce the hormone during early pregnancy, the placenta takes over this function later in gestation.
**Option B:** This option is incorrect because β-hCG is not produced by the pituitary gland. While the pituitary gland regulates various hormonal functions, β-hCG production is a placental function.
**Option C:** This option is incorrect because β-hCG is not secreted by the testes. Although the testes produce testosterone and other hormones, β-hCG production is unique to the placenta during pregnancy.
**Clinical Pearl / High-Yield Fact**
It's essential to remember that β-hCG levels can be elevated in certain types of cancers, such as choriocarcinoma and germ cell tumors, making it a valuable tumor marker in clinical practice.
**Correct Answer: D. Placenta**