Question

Which of the following hormone is not secreted by the human placenta:

• A. Estrogen
• B. hCG
• C. LH
• D. Progesterone

Hint:

Remember, LH is a pituitary hormone and not secreted by the placenta. The placenta secretes hormones like estrogen, progesterone, and hCG to maintain pregnancy.

Answer 1

The Correct Option is C

Step 1: Hormones secreted by the human placenta. The placenta plays a vital role in maintaining pregnancy by secreting key hormones such as: 
- Estrogen: Essential for the development of the uterus and preparation for childbirth.
 - Progesterone: Maintains the uterine lining and prevents contractions during pregnancy. 
- hCG (Human Chorionic Gonadotropin): Supports the corpus luteum to continue progesterone production in early pregnancy. 

Step 2: Why LH is not secreted by the placenta. Luteinizing hormone (LH) is secreted by the anterior pituitary gland, not by the placenta. LH primarily triggers ovulation and the formation of the corpus luteum in the ovaries. 

Step 3: Incorrect options explained. - Estrogen, hCG, and Progesterone are all secreted by the placenta to support pregnancy.

Answer 2

The question asks which hormone is NOT secreted by the human placenta. Let's check where each of the four hormones actually comes from.

1. Estrogen: The placenta produces large amounts of estrogen during pregnancy, which supports uterine growth and helps prepare the body for delivery. This hormone is indeed secreted by the placenta.
2. hCG: Human chorionic gonadotropin is produced by the placenta from very early in pregnancy, and it signals the corpus luteum in the ovary to keep producing progesterone until the placenta can take over that role.
3. LH: Luteinizing hormone is made by the anterior pituitary gland, not the placenta. Its normal job is to trigger ovulation and support the corpus luteum before pregnancy begins, and its production is actually suppressed once pregnancy is established.
4. Progesterone: The placenta takes over progesterone production as pregnancy advances, and this hormone is essential for keeping the uterine lining stable and preventing early contractions.

Estrogen, hCG, and progesterone are all placental hormones central to maintaining pregnancy, while LH comes from the pituitary gland and is not one of the placenta's products.

So the correct answer is LH.