BIOL 320 1st Edition Lecture 25 Outline of Last Lecture I Male Reproduction a Structures b Sexual Responses c Spermatogenesis d Sertoli Cells e Testosterone f Hormonal Control g Problems with Exogenous Testosterone h Developmental Aspects Outline of Current Lecture II Female Reproduction a Structures b Oogenesis c Ovarian Cycle d Menstrual Cycle e Estrogen Progesterone Effects f Sexual Response g Developmental Aspects III Conception a Window of Opportunity b Specifics c Mechanism of Action d Pre embryonic Development e Implantation f Contraception g Placentation Current Lecture Female Reproduction Structures o 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 arteries o 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 luteum o 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 cavity 2 Cilia on fimbria create drawing currents oocyte to uterine tube 3 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 Isthmus o 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 Disease o 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 glands o Stratum basalis non hormonally responsive layer present all the time o Stratum functionalis hormonally responisve layer forms anew with each cycle layer that sheds during flow phase caused by degeneration of spiral arteries o Vagina Location between bladder rectum Urethra embedded in anterior wall Function 1 Passage way for birth menstrual flow 2 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 cervix o 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 Oogenesis o Definition production of female gametes via meiosis o In the fetal period 1 Oogonia multiply by mitosis 2 Primordial follicles appear primary oocytes 3 Primary oocytes start meiosis I but stall in prophase I o At and after puberty 1 One primary oocyte 2 haploid cells polar body secondary oocyte 2 Secondary oocyte arrests in metaphase II 3 If penetrated by sperm then the secondary oocytes complete meiosis II large ovum second polar body Ovarian Cycle o Definition monthly series of events associated with maturation of the egg o Two Phases Follicular phase steps 1 6 1 Thecal granulosa cells produce estrogens 2 Zona pellucida forms around oocyte 3 Antrum formation occurs secondary follicle secondary follicle Graafian follicle 4 Antrum enlarges corona radiata forms 5 Follicles bulges from surface of ovary 6 Primary oocyte completes meiosis I Luteal phase steps 7 9 days 14 28 1 Ruptured follicle collapses 2 Granulosa cells enlarge with thecal cells corpus luteum 3 Corpus luteum secretes estrogen progesterone 4 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 down Days 26 28 ovarian hormone production declines LH FSH no longer inhibited so cycle starts again Menstrual Cycle o o o o Definition cyclical changes in uterine lining in response to ovarian hormones Days 1 5 flow phase all but deepest layers of lining are shed Days 6 14 proliferative phase endometrium rebuilds self Days 15 28 secretory phase getting ready for implantation very vascular glands extend deep into lining o If fertilization does not occur 1 Progesterone levels decline 2 Hormonal support of endometrium is gone 3 Spiral arteries kink spasm endometrial cells die 4 Functional layer digests self 5 Spiral arteries constrict