Menstrual CycleMichal Ovecka

Introduction Unlike some animals, Humans can reproduce during any time of the year

In the females this involves the menstrual cycle - production of an oocyte inside the follice

Thickening of the lining of the uterus When no embryo is formed, the thickening is broken down and passed out of the body during menstruation

Phases of the Menstrual cycle Follicular phase Ovulation Luteal phase Menstruation

Follicular phase Pituitary gland secretes FSH

Follicular phase Stimulating a group of follicles, the containing eggs and estrogen secretion by cells of the follicles

While the eggs are going through development the lining of the uterus (endometrium) begins to repair, due to increasing levels of estrogen

Estrogen levels reach a peak, thus stimulating LH secretion by the pituitary gland

Ovulation LH rises to a peak causing the most developed follicle to release an egg into the oviduct (the other follicles degenerate)

LH causes the follicle cells to secrete less estrogen and more progesterone.

The LH causes the follicle which released the egg to develop into corpus luteum.

The corpus luteum secretes progesterone which develops the endometrium

The development of the endometrium prepares the egg for the implantation of an embryo

Menstruation High levels of progesterone and estrogen levels inhibit FSH and LH secretion

If fertilization does not occur, the corpus luteum degenerates and the lining of the uterus breaks down - for shedding during menstruation

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Bibliography http://upload.wikimedia.org/wikipedia/commons/a/a5/Hypophyse.png

http://www.ux1.eiu.edu/~cfjcd/Menstrual_Cycle.pdf

https://www.theeveningjava.com/images/femalerepro..jpg

Allot, Andrew. IB Study Guides Biology. Second ed. Glasgow: Oxford UP, 2007. Print.