HCG is produced by –
**Core Concept**
Human chorionic gonadotropin (HCG) is a hormone produced during pregnancy, playing a crucial role in maintaining the corpus luteum and supporting embryonic development. It is a glycoprotein hormone similar to luteinizing hormone (LH) and follicle-stimulating hormone (FSH).
**Why the Correct Answer is Right**
HCG is produced by the placenta, specifically by the syncytiotrophoblast cells, which are a layer of trophoblast cells that fuse to form a multinucleated cell layer. This hormone is essential for pregnancy, as it maintains the corpus luteum, preventing its regression and ensuring continued production of progesterone, which is necessary for embryonic development. The placenta produces HCG throughout pregnancy, peaking around 10 weeks of gestation.
**Why Each Wrong Option is Incorrect**
**Option A:** This option is incorrect as it does not specify the correct source of HCG production. The placenta is the correct source, not the ovaries or uterus.
**Option B:** This option is incorrect as it is not a known source of HCG production. While the pituitary gland does produce luteinizing hormone (LH), which is similar to HCG, it is not the source of HCG itself.
**Option C:** This option is incorrect as the corpus luteum is a structure that produces progesterone in response to HCG, but it is not the source of HCG production.
**Clinical Pearl / High-Yield Fact**
It is essential to remember that HCG levels are used as a marker for pregnancy and can be elevated in certain conditions such as choriocarcinoma and gestational trophoblastic disease.
**Correct Answer:** C. The placenta.