The ovary produces two main sex steroid hormones estrogen and progesterone. Both of them are important for uterus thickening and play an important role in female reproduction.Complete answer:
The female reproductive system comprises Pair of ovaries, oviducts, uterus, cervix, vagina, and the exterior genitalia.
Ovaries: Ovary is a sex organ that is responsible for the production of the ovum (gamete) as well as various steroid sex hormones.
Uterus: The uterus supports the baby during pregnancy. It is also called the womb. The uterine wall has three layers namely perimetrium, myometrium, and endometrium. The endometrium plays a role in menstruation and the myometrium shows strong contraction during child delivery.
The function of the ovary:-
-The mature female gamete development is called oogenesis.
-Oogenesis will begin during embryonic development when more than a million oogonia (mother cells) forms within each of these ovaries. Oogonia will not be formed after the childbirth.
-The oogonia will meiotically undergo division and get arrested at prophase-I temporarily. This stage is called a primary oocyte.
-Each primary oocyte will then be surrounded by granulosa cell layers and they are called primary follicles.
-Some of the primary oocytes degenerate before puberty. At puberty, 60000 to 80000 primary follicles will only be present.
-The primary follicles will now get surrounded by more layers of granulosa cells and theca cells. It is called a secondary follicle.
-The secondary follicle gets converted to the tertiary follicle and eventually, it forms the Graafian follicle.
-The Graafian follicle will release the secondary oocyte from the ovary. This process is called ovulation.
The function of the uterus:-
-The blastomere is arranged into an exterior trophoblast layer and an inner cell mass. The trophoblast attaches itself to the uterus endometrial layer and the inner cell mass gradually forms an embryo.
-Post attachment, the cells in the uterus will undergo rapid division and will cover the blastocyst. Now, the blastocyst will be attached to the uterus endometrial layer. This is known as implantation and it further leads to pregnancy.Note:
The delivery of a baby is called parturition. The fully developed fetus and the placenta sends a signal which will stimulate mild uterine contraction. This contraction will cause oxytocin hormone from the pituitary. Oxytocin will further cause forceful myometrium contraction which will lead to the birth of the baby.