Gonads = ovaries. Gametes = ova (one/month). Unlike the male, mostly internal. Female repro system must produce gametes AND maintain developing embryo. | Ch 24: The Reproductive System, Part 2 pp 723-747 Gonads = ovaries Gametes = ova (one/month) Unlike the male, mostly internal Female repro system must produce gametes AND maintain developing embryo Overview of Anatomy Ovaries Retroperitoneal Broad Ligament Suspensory Ligament Functions: Ovum production Hormone production Circulation: Ovarian Artery and Vein Histology Capsule: Tunica albuginea Germinal epithelium (misnomer) Ovarian cortex with developing gametes Medulla has blood supply Oogenesis (= ovum production) Takes place inside ovarian follicles in ovaries as part of ovarian cycle Oogonia (= stem cells) complete mitotic divisions before birth At birth: ~ 2x106 primary oocytes At puberty: ~ 400,000 primary oocytes 40 years later: 0 (even though only ~ 500 used) Atresia Ovulation Oogenesis Fig Ovarian cycles start at puberty under influence of estrogen. Oogenesis Primordial follicle A dormant stage, ready to develop Each month some proceed Most (99%) atrophy (atresia) . | Ch 24: The Reproductive System, Part 2 pp 723-747 Gonads = ovaries Gametes = ova (one/month) Unlike the male, mostly internal Female repro system must produce gametes AND maintain developing embryo Overview of Anatomy Ovaries Retroperitoneal Broad Ligament Suspensory Ligament Functions: Ovum production Hormone production Circulation: Ovarian Artery and Vein Histology Capsule: Tunica albuginea Germinal epithelium (misnomer) Ovarian cortex with developing gametes Medulla has blood supply Oogenesis (= ovum production) Takes place inside ovarian follicles in ovaries as part of ovarian cycle Oogonia (= stem cells) complete mitotic divisions before birth At birth: ~ 2x106 primary oocytes At puberty: ~ 400,000 primary oocytes 40 years later: 0 (even though only ~ 500 used) Atresia Ovulation Oogenesis Fig Ovarian cycles start at puberty under influence of estrogen. Oogenesis Primordial follicle A dormant stage, ready to develop Each month some proceed Most (99%) atrophy (atresia) Oogenesis 2. Primary follicle (days 3-8) 1. Double layer of theca cells 2. Enlargement due to estrogen 3. More atresia Oogenesis Secondary follicle (days 8-10) Liquor folliculi appears Theca more developed Granulosa cells producing estrogen, under influence of FSH Zona pellucida visible Oogenesis Tertiary (Graafian) follicle (days 11-14) 1. Ready for ovulation 2. Theca well developed 3. Granulosa cells secreting estrogen 4. First meiosis completed Tertiary or Graafian Follicle Spans entire width of cortex First meiotic division being completed: 1 oocyte divides into one 2 oocyte and one polar body Ovarian cyst Cyst = bag, usually filled with fluid Usually follicular or luteal cysts. Oocyte and follicular cells shed into abdominal cavity and collected by fimbria then Empty follicle forms corpus luteum which produces progesterone Corpus luteum degenerates and becomes corpus albicans GnRH increases under low estrogen and progesterone levels Ovulation Menstrual Cycle Day 1: first day of .
