Female Hormonal Cycle

• The female gamete is an ovum.
• Each ovum is protected by a follicle. FSH stimulates further maturation of this follicle, and it begins to secrete estrogen whilst moving along the ovary.
• Estrogen stimulates proliferation of the endometrium in preparation for implantation. It also encourages the cervix to release thinner mucus to allow for fertilisation.
• Once estrogen levels peak, the pituitary gland will release a surge of LH. This triggers ovulation.
• At Day 14, ovulation occurs. The ovum is released into the oviduct, and the follicle develops into a corpus luteum, which secretes progesterone.
• Progesterone promotes further vascularisation of the endometrium in preparation of implantation.
• Vascularisation is the formation of body tissue with capillaries.
• High levels of estrogen and progesterone will inhibit the secretion of FSH and LH from the pituitary gland, preventing the development of any ova.
• If fertilisation occurs in the oviduct, the ovum will turn into a zygote. It will then enter the uterus for implantation and embryo development. The corpus luteum will not degenerate, continuing to secrete progesterone, so its levels remain high to preserve the endometrium.
• If fertilisation does not occur, the corpus luteum will degenerate, resulting in a drop of progesterone. The endometrium will start to degrade; leading to the onset of menstruation.
• Label the diagram below:

  Α) Oviduct

  B) Ovary

  C) Cervix

  D) Vagina

  E) Uterus

  F) Muscular Wall

  G) Endometrium