1. Oogenesis
Production of Ova

2. What is Oogenesis
The formation, development, and maturation of an ovum.

3. Oogenesis begins in the female embryo
Primoridal germ cells differentiate into oogoina (stem cells)
At 2 – 7 months of gestation, ~ oogonia divide to form ~ 7 million germ cells

4. The meiotic resting phase is called the dictyotene
From 7 – 9 months, most oogonia die
the remaining enter the first meiotic division
primary oocyte
 The primary oocytes remain resting within small follicles until puberty

5. Ovary

6. Process of Ovulation Started by drop in estrogen
Signals hypothalamus to release GnRH
GnRH goes to pituitary, and it relases FSH
Increase in FSH stimulates about ~20 oocytes to mature
Meiosis I to form secondary oocyte
One oocyte (in most cases) matures and is expelled. The others are reabsorbed before ovulation occurs
The process of ovulation is started and controlled by a drop in the hormone estrogen (mostly etradiol) to a low level. When the drop in estrogen levels occurs the hypothalamus (a part of the brain) is signaled to increase its secretion of gonadotropin-releasing hormone (GnRH) thus sending a message to the pituitary gland to increase its secretion of follicle-stimulating hormone (FSH). The increase in FSH causes the growth of ten to 20 of the ovarian follicles

8. Follicle
Estrogen and progesterone are secreted by some of the cells in the follicle
Cytoplasm and nutrients
Ovulation occurs when follicle and ovarian surface open

9. Corpus leuteum The empty follicle becomes the corpus leuteum
If pregnancy does not occur, it is reabsorbed
If pregnancy does occur, it produces hormones that help maintain pregnancy