Gonadotropic hormones and their effect on ovaries

The ovarian changes during the female sexual cycle depend completely on the hormones FSH and LH secreted by the anterior pituitary.

The ovaries that are not stimulated by these hormones remain inactive, that’s what occurs in childhood when no FSH and LH secreted. At ages of 9-10 years the anterior pituitary begin to secrete FSH and LH which results in female sexual cycle between age of 11-16 years. This period is called puberty and the first menstrual cycle is called menarche. During fetal life, the ovaries are stimulated by hCG from the placenta but after birth the stimulation is lost.

Both FSH and LH are glycoproteins, during each month the is a cyclical increase or decrease of both FSH and LH, FSH and LH stimulate their ovarian target cells by combination with highly specific FSH and LH receptors in the cell membrane, the activated receptors in turn increase the rate of secretion of these cells and their growth and their proliferation.