ovulation

activity anatomical anatomy beginnings biology birth cell competition coupling cycle egg endometrium estrogen female fertilication fertilisation fertility fertilization fetus follicle follicles genetic gynecology hormone human illustration life love luteal magnification male medicine menses menstrual menstruation micro oocyte organism ovarian ovaries ovary ovulation ovule ovum pairing parent penetration phase pregnancy proliferative reproductive secretory sex sexual sperm spermatozoon stimulating uterine