27Hormonal Interactions During the Ovarian CycleSlide 3Slide 4Slide 5Feedback Mechanisms in Ovarian FunctionUterine (Menstrual) CycleMensesGonadotropins, Hormones, and the Ovarian and Uterine CyclesSlide 10Extrauterine Effects of Estrogens and ProgesteroneEstrogen-Induced Secondary Sex CharacteristicsFemale Sexual ResponseSlide 14Sexually Transmitted Diseases: GonorrheaSexually Transmitted Diseases: SyphilisSlide 17Sexually Transmitted Diseases: ChlamydiaSexually Transmitted Diseases: Viral InfectionsDevelopmental Aspects: Genetic Sex DeterminationDevelopmental AspectsDevelopment of Internal Reproductive OrgansSlide 23Slide 24Slide 25Slide 26Development of External Genitalia: MaleSlide 28Slide 29Development of External Genitalia: FemaleSlide 31Slide 32Development Aspects: Descent of the GonadsSlide 34Slide 35Slide 36Development Aspects: PubertyMenopauseCopyright © 2006 Pearson Education, Inc., publishing as Benjamin CummingsHuman Anatomy & PhysiologySEVENTH EDITIONElaine N. MariebKatja HoehnPowerPoint® Lecture Slides prepared by Vince Austin, Bluegrass Technical and Community CollegeC H A P T E R27The Reproductive SystemP A R T CCopyright © 2006 Pearson Education, Inc., publishing as Benjamin CummingsHormonal Interactions During the Ovarian CycleDay 1 – GnRH stimulates the release of FSH and LHFSH and LH stimulate follicle growth and maturation, and low-level estrogen releaseRising estrogen levels:Inhibit the release of FSH and LH Prod the pituitary to synthesize and accumulate these gonadotropinsCopyright © 2006 Pearson Education, Inc., publishing as Benjamin CummingsHormonal Interactions During the Ovarian CycleEstrogen levels increase and high estrogen levels have a positive feedback effect on the pituitary, causing a sudden surge of LHCopyright © 2006 Pearson Education, Inc., publishing as Benjamin CummingsHormonal Interactions During the Ovarian CycleThe LH spike stimulates the primary oocyte to complete meiosis I, and the secondary oocyte continues on to metaphase IIDay 14 – LH triggers ovulationLH transforms the ruptured follicle into a corpus luteum, which produces inhibin, progesterone, and estrogenCopyright © 2006 Pearson Education, Inc., publishing as Benjamin CummingsHormonal Interactions During the Ovarian CycleThese hormones shut off FSH and LH release and declining LH ends luteal activityDays 26-28 – decline of the ovarian hormones Ends the blockade of FSH and LHThe cycle starts anewCopyright © 2006 Pearson Education, Inc., publishing as Benjamin CummingsFeedback Mechanisms in Ovarian FunctionFigure 27.21Copyright © 2006 Pearson Education, Inc., publishing as Benjamin CummingsUterine (Menstrual) CycleSeries of cyclic changes that the uterine endometrium goes through each month in response to ovarian hormones in the bloodDays 1-5: Menstrual phase – uterus sheds all but the deepest part of the endometriumDays 6-14: Proliferative (preovulatory) phase – endometrium rebuilds itselfDays 15-28: Secretory (postovulatory) phase – endometrium prepares for implantation of the embryoCopyright © 2006 Pearson Education, Inc., publishing as Benjamin CummingsMensesIf fertilization does not occur, progesterone levels fall, depriving the endometrium of hormonal supportSpiral arteries kink and go into spasms and endometrial cells begin to dieThe functional layer begins to digest itselfSpiral arteries constrict one final time then suddenly relax and open wideThe rush of blood fragments weakened capillary beds and the functional layer sloughsCopyright © 2006 Pearson Education, Inc., publishing as Benjamin CummingsGonadotropins, Hormones, and the Ovarian and Uterine CyclesFigure 27.22a, bCopyright © 2006 Pearson Education, Inc., publishing as Benjamin CummingsGonadotropins, Hormones, and the Ovarian and Uterine CyclesFigure 27.22c, dCopyright © 2006 Pearson Education, Inc., publishing as Benjamin CummingsExtrauterine Effects of Estrogens and ProgesteroneEstrogen levels rise during pubertyPromote oogenesis and follicle growth in the ovaryExert anabolic effects on the female reproductive tractUterine tubes, uterus, and vagina grow larger and become functionalUterine tubes and uterus exhibit enhanced motilityVaginal mucosa thickens and external genitalia matureCopyright © 2006 Pearson Education, Inc., publishing as Benjamin CummingsEstrogen-Induced Secondary Sex CharacteristicsGrowth of the breastsIncreased deposition of subcutaneous fat, especially in the hips and breastsWidening and lightening of the pelvisGrowth of axillary and pubic hairCopyright © 2006 Pearson Education, Inc., publishing as Benjamin CummingsFemale Sexual ResponseThe clitoris, vaginal mucosa, and breasts engorge with bloodActivity of vestibular glands lubricates the vestibule and facilitates entry of the penisOrgasm – accompanied by muscle tension, increase in pulse rate and blood pressure, and rhythmical contractions of the uterusCopyright © 2006 Pearson Education, Inc., publishing as Benjamin CummingsFemale Sexual ResponseFemales do not have a refractory period after orgasm and can experience multiple orgasms in a single sexual experienceOrgasm is not essential for conceptionCopyright © 2006 Pearson Education, Inc., publishing as Benjamin CummingsSexually Transmitted Diseases: GonorrheaBacterial infection spread by contact with genital, anal, and pharyngeal mucosal surfacesSigns and symptomsIn males – painful urination, discharge of pus from the penis In females – none (20%), abdominal discomfort, vaginal discharge, abnormal uterine bleedingLeft untreated, can result in pelvic inflammatory diseaseTreatment: antibiotics, but resistant strains are becoming more prevalentCopyright © 2006 Pearson Education, Inc., publishing as Benjamin CummingsSexually Transmitted Diseases: SyphilisBacterial infection transmitted sexually or contracted congenitallyInfected fetuses are stillborn or die shortly after birthA painless chancre appears at the site of infection and disappears in a few weeksCopyright © 2006 Pearson Education, Inc., publishing as Benjamin CummingsSexually Transmitted Diseases: SyphilisSecondary syphilis shows signs of pink skin rash, fever, and joint painA latent period follows, which may progress to tertiary syphilis characterized by gummas (lesions of the CNS, blood vessels, bones, and skin)Treatment: penicillinCopyright ©