a) Arrange the following hormones in sequences of their secretion in a pregnant woman.
b) Mention their source and the function they perform:
hcG, LH, FSH, Relaxin.

Explanation

a) FSH, LH, hcG, hPL
b) GnRH(Gonadotropin- releasing hormone) that stimualtes the anterior pituitary to the ganadotropic hormones. There are two gonadotropic hormones- FSH (Follicle Stimulating Hormone) and LH(Luteinzing Hormone)-in both males and females.
In males- FSH acts on sertoli cells and stimulates secretion of Androgens. Androgens stimulates the process of spermatogenesis.
In females -FSH and LH affect the ovaries and uterus and the monthly cycle begins. Gonadotropins (LH and FSH) increase gradually during the follicular phase and stimulates follicular development as well as secretion of estrogen by the following follicles.
FSH stimulates the follicle to produce estrogen, and LH stimulates the corpus luteum to produce progestrone.
hcG: if fertilization and implantation do occur, the corpus luetum is maintained by hcG, which takes the job of pituitary LH after fertilization.
Relaxin: hcG, hPL and relaxin are produced in women only during pregnancy. In the later phase of pregnancy, a hormone called relaxin is also secreted by the ovary.