BIOL 320 1st Edition Lecture 25Outline of Last Lecture I. Male Reproductiona. Structuresb. Sexual Responsesc. Spermatogenesisd. Sertoli Cellse. Testosteronef. Hormonal Controlg. Problems with Exogenous Testosteroneh. Developmental AspectsOutline of Current Lecture II. Female Reproductiona. Structuresb. Oogenesisc. Ovarian Cycled. Menstrual Cyclee. Estrogen & Progesterone Effectsf. Sexual Responseg. Developmental AspectsIII. Conceptiona. Window of Opportunityb. Specificsc. Mechanism of Actiond. Pre-embryonic Developmente. Implantationf. Contraceptiong. PlacentationCurrent LectureFemale Reproduction- Structureso Ovary -Primary functions:- Produce gametes- Produce sex hormones Ligaments:- -Ovarian: anchors ovary to uterus- -Broad: piece of visceral peritoneum that contains suspensory & mesovarium ligaments- -Suspensory: anchors ovary to lateral pelvic wall- -Mesovarium: suspends ovary in between Blood supply:- -Ovarian arteries: branch from abdominal aorta- -Ovarian branches of uterine arterieso Travel through suspensor & mesovarium ligaments -Surrounded by: --Tunica albuginea: fibrous connective tissue --Germinal epithelium: outermost layer; simple cuboidal -Medulla: blood vessels & nerves -Cortex: imbedded with ovarian follicles -Follicle = an oocyte & follicle cells & granulosa cells (hormone producing cells) -Follicle types: --Primordial: single layer of cells around oocyte  --Primary: follicular cells --> granulosa cells --Secondary: antrum formation (fluid-filled space in granulosa cells) --Graafian: secondary follicle at most mature stage --Corpus luteum: ruptured follicle (stays for 10 days) --Corpus albicans: degenerating corpus luteumo Uterine Tubes -Functions: receive ovulated oocyte; site of fertilization; carries oocyte to uterus -Uterine tubes…have NO physical contact with ovaries -Upon ovulation:1. Ovulated oocyte released into peritoneal cavity2. Cilia on fimbria create drawing currents --> oocyte to uterine tube3. Oocyte carried to uterus by peristalsis & ciliary action -Non-ciliated cells…keep oocyte & sperm moist & nourished -Mesosalpinx: portion of broad ligament that supports uterine tube -Regions: --Fimbriae --Infundibulum --Ampulla --Isthmuso Uterus -Regions: --Body --Fundus --Isthmus -Cervis --Cervical glands: secrete mucous which prevent sperm entry except at mid-cycle (when thinned due to estrogen) -Support --Mesometrium --Lateral cervical ligaments --Uterosacral ligaments --Round ligaments: bind anterior wall to labia majora -Uterine tubes: Ovary? Problems? -Ectopic pregnancy: egg gets fertilized outside of uterine tubes (usually spontaneously abort) -Pelvic Inflammatory Diseaseo Uterine Wall -Blood supply --Uterine arteries --Arcuate arteries --Radial branches -Layers --Perimetrium: outermost serous layer…base layer --Myometrium: smooth muscle…middle layer --Endometrium: mucousal lining; contain uterine glandso ---Stratum basalis: non-hormonally responsive layer…present all the timeo ---Stratum functionalis: hormonally responisve layer…forms anew with each cycle; layer that sheds during "flow" phase; caused by degeneration of spiral arterieso Vagina -Location: between bladder & rectum -Urethra: embedded in anterior wall -Function:1. Passage way for birth & menstrual flow2. Organ of copulation -Histology: --Adventitia: fibrous & elastic connective tissue --Muscularis: smooth muscle --Mucosa: stratified squamous epithelial tissue -Hymen: incomplete partition of vaginal orifice of mucosa -Vaginal fornix: area surrounding the cervixo External Genitalia: Vulva -Mons pubis: fatty, haired skin overlies pubic symphysis -Labia majora: fatty, haired skin; homologous to scrotum -Labia minora: hair free, inner fold; homologous to ventral penis -Greater vestibular glands: (pea-sized gland) produce mucous that keep vestibule moist & lubricated; homologous to bulbourethral glands -Clitoris: erectile tissue; hooded by prepuce; exposed portion = glans; homologous to penis -Perineum: --Diamond over: pubic symphysis, ischial tuberosities, coccyx- Oogenesiso -Definition: production of female gametes via meiosiso -In the fetal period:1. Oogonia multiply by mitosis2. Primordial follicles appear --> primary oocytes3. Primary oocytes start meiosis I but stall in prophase Io -At and after puberty:1. One primary oocyte --> 2 haploid cells (polar body & secondary oocyte)2. Secondary oocyte arrests in metaphase II3. If penetrated by sperm, then the secondary oocytes complete meiosis II --> large ovum & second polar body- Ovarian Cycleo -Definition: monthly series of events associated with maturation of the eggo -Two Phases: --Follicular phase: (steps 1-6)1. Thecal & granulosa cells produce estrogens2. Zona pellucida forms around oocyte3. Antrum formation occurs (secondary follicle); secondary follicle --> Graafian follicle4. Antrum enlarges; corona radiata forms5. Follicles bulges from surface of ovary6. Primary oocyte completes meiosis I --Luteal phase: (steps 7-9)…days 14-281. Ruptured follicle collapses2. Granulosa cells enlarge & with thecal cells --> corpus luteum3. Corpus luteum secretes estrogen & progesterone4. If no pregnancy, corpus luteum last 10 days. If fertilization occurs, corpus luteum last 3 months (produce hormones to maintain endometrium until placenta takes over)5. Corpus albicans: scar of degenerated corpus luteum -Ovulation: Graafian follicle burst releasing oocyte; "mittelschmerz" = twinge felt by some women at ovulation; 1-2% ovulation => more than primary oocytes = fraternal twins -Establishment: during childhood, ovaries grow & secrete low estrogen --> inhibit release of GnRH (from ventral hypothalamus). During puberty, GnRH released --> FSH & LH act on ovaries. Therefore, adult cyclical pattern. -Hormone Interactions- --Day 1: GnRH stimulate release of FSH & LH --> stimulate follicle growth/maturation --> low estrogen levels- --Before day 14: estrogen levels rising --> inhibit FSH & LH (anterior pituitary accumulates them)- --Day 14: high levels of estrogen positive feedback on LH/FSH => surge of LH & FSH --> formation of secondary oocyte (metaphase II), ovulation occurs, corpus luteum formed- --After day 14: corpus luteum produces inhibin, estrogen & progesterone; LH/FSH production shuts