Oogenesis

Human Reproduction: Females A. The female reproductive system is adapted to produce eggs, receive the penis and sperm, and protect and nourish the embryo during and after pregnancy 1. The processes of the female reproductive system are regulated by the hormones secreted by the ovaries, the hypothalamus and the anterior lobe of the pituitary gland

B. The ovaries produce gametes and sex hormones 1. Oogenesis occurs in the ovaries 2. Oogenesis begins with the development of oogonia, which become primary oocytes during prenatal development 3. Each primary oocyte and the cells surrounding it form a follicle 4. Each month, a primary oocyte completes the first meiotic division forming a first polar body and the secondary oocyte This polar body is much smaller due to unequal distribution of the cytoplasm

5. The first polar body may undergo a further division 5. The first polar body may undergo a further division or not; in either event, the polar bodies ultimately disintegrate 6. The secondary oocyte remains in meiosis II until fertilization 7. Oogenesis results in one haploid ovum 8. The cells of the follicle secrete fluid, as well as estrogen 9. Typically, one follicle matures fully each month 10. The secondary oocyte is ejected from the follicle during ovulation 11. The remaining follicular cells form the corpus luteum a. The corpus luteum is a temporal endocrine organ that secretes progesterone and estrogens

Comparison of Oogenesis and Speratogenesis