The female estrus cycle

The female estrus cycle

• The anterior pituitary gland secrets a hormone called follicle stimulating hormone (S.H.)  which stimulates the growth of Graafian follicles in the ovary
• It also stimulates the ovary to secrete a female sex hormone – estrogen.
• Estrogen causes the signs of heat in females and also stimulates the anterior pituitary glands to produce another hormone called Luteinizing hormone (LH).
• Estrogen makes the female animal more receptive to the male and increases sex urge in females.
• Luteinizing hormone causes the rapture of mature follicles to release the ova in the process of ovulation.
• After ovulation, luteinizing hormone stimulates the development of the yellow body (corpus luteum) from the remains of the follicles.
• The corpus luteum produces a hormone known as progesterone which stimulates the growth of the endometrium in preparation for implantation.
• Progesterone also inhibits the release of follicle stimulating hormone and luteinizing hormone from the anterior pituitary gland.
• After a successive fertilization, the progesterone stimulates the growth and improves blood supply to the endometrium for successful implantation.
• After implantation, the corpus luteum degenerates and the placenta becomes the new source of progesterone.