Question

Which of the following hormone is not secreted by placenta?

• A. HCG
• B. HPL
• C. Relaxin
• D. Estrogen, progesterone

Hint:

Major placental hormones (NCERT): \[ \boxed{ \begin{aligned} &HCG\\ &HPL\\ &Estrogen\\ &Progesterone \end{aligned} } \] Remember: \[ \boxed{\text{Placenta = HCG + HPL + Estrogen + Progesterone}} \] These hormones maintain pregnancy and promote fetal development.

Answer 1

The Correct Option is C

Concept: The placenta functions as an endocrine gland during pregnancy. It secretes several hormones essential for the maintenance of pregnancy and fetal development. Major placental hormones include: \[ \boxed{ \begin{aligned} &HCG \;(\text{Human Chorionic Gonadotropin})\\ &HPL \;(\text{Human Placental Lactogen})\\ &\text{Estrogen}\\ &\text{Progesterone} \end{aligned} } \] Relaxin is mainly secreted by the corpus luteum of the ovary (and later in small amounts during pregnancy), and is generally not considered a principal placental hormone in standard NCERT-based questions.

Step 1: Identify the hormones secreted by the placenta.
The placenta secretes \[ \boxed{ HCG,\; HPL,\; Estrogen,\; Progesterone. } \] These hormones maintain pregnancy and support fetal growth.

Step 2: Analyse Relaxin.
Relaxin helps in

• Relaxation of pelvic ligaments.

• Softening of the cervix before childbirth.
According to the NCERT syllabus, it is primarily associated with the corpus luteum rather than being listed among the major placental hormones.

Step 3: Choose the correct option.
Thus, \[ \boxed{\textbf{Relaxin}} \] is the hormone that is not considered a placental hormone in this context. Hence, \[ \boxed{\textbf{Option (C)}} \] is the correct answer.