Y khoa - Dược - Chapter 32: The reproductive system

32The Reproductive SystemLearning Outcomes (cont.)32.1 Summarize the organs of the male reproductive system including the locations, structures, and functions of each.32.2 Describe the causes, signs and symptoms, and treatment of various disorders of the male reproductive system.32.3 Summarize the organs of the female reproductive system including the locations, structures, and functions of each.32.4 Describe the causes, signs and symptoms, and treatment of various disorders of the female reproductive system.Learning Outcomes (cont.)32.5 Explain the process of pregnancy, including fertilization, the prenatal period, and fetal circulation. 32.6 Describe the birth process, including the postnatal period.32.7 Compare several birth control methods and their effectiveness. 32.8 Explain the causes of and treatments for infertility.32.9 Describe the causes, signs and symptoms, and treatments of the most common sexually transmitted infections.Introduction Male and female reproductive systems Function together to produce offspring Produce important hormones The Male Reproductive System TestesProduce sperm and testosteroneDivided into lobulesHeld in the scrotumSeminiferous tubulesIn the lobules of the testesContain spermatogenic cells Interstitial cells produce testosteroneMale SystemBackSperm Cell FormationSpermatogenesisSpermatogonium (46 chromosomes)Primary spermatocytes (46 chromosomes)MitosisSecondary spermatocyteSecondary spermatocyteMeiosis at pubertySpermatidSpermatidSpermatidSpermatid2nd meiotic divisionSperm Cell Formation (cont.)HeadNucleus with 23 chromosomesCovered by an acrosome Midpiece - mitochondriaTail Flagellum Propelsthe sperm Internal Accessory Organs – Male Epididymis – where spermatids mature into spermVas deferens – carries sperm cells to urethraSeminal vesicles – secrete seminal fluid Sugar Prostaglandins Male SystemInternal Accessory Organs – Male (cont.) Prostate gland Alkaline fluid that protects sperm Contractions assist with expulsion of semenCowper’s glands – fluid to lubricate end of penisSemen Sperm cellsFluids Male SystemExternal Organs – Male ScrotumPouch that holds the testes away from the bodyLined with serous membrane that secrets fluidPenisShaftGlans penis Prepuce FunctionsDeliver spermUrinationMale SystemErection, Orgasm, and Ejaculation Erection – erectile tissue becomes engorged with bloodOrgasm - emission occursEjaculation – semen is forced out of the urethraMale Reproductive HormonesGonadotropin-releasing hormone (GnRH) Follicle-stimulating hormone (FSH) Luteinizing hormone (LH) TestosteroneSecondary sex characteristicsMaturation of male reproductive organsRegulated by negative feedbackApply Your KnowledgeMatching: ___ Vasectomy ___ Mixture of sperm and fluids ___ Sperm cell formation ___ Secrete alkaline fluid/  prostaglandins___ Produce testosterone ___ GnRH ___ Erectile tissue GEFACBDANSWER:Correct!SpermatogenesisTestesPenisVas deferensHypothalamusSemenSeminal vesicleCommon Diseases and Disorders of the Male Reproductive SystemDisease/DisorderDescriptionBenign prostatic hypertrophy (BPH)Nonmalignant enlargement of the prostate glandEpididymitisInflammation of an epididymis; usually starts as an urinary tract infectionImpotence or erectile dysfunction (ED)Disorder in which erection cannot be achieved or maintained; about 50% of males between 40 and 70 have some degree of EDCommon Diseases and Disorders of the Male Reproductive System (cont.)Disease/DisorderDescriptionProstate cancerMost common form of cancer in men over 40; risk increases with ageProstatitisInflammation of the prostate gland; may be acute or chronicTesticular cancerMalignant growth in one or both testicles; more common in males 15–30 years; aggressive malignancyApply Your KnowledgeMatch: More common in men over 40 years old. Common in older men; symptoms  include difficulties with urination. More common in males 15-30 years  old; aggressive. Often starts as urinary tract infection; symptoms include swelling of the  scrotum and painful ejaculation.BPHEpididymitisProstrate cancerTesticular cancerANSWER: ABCDThe Female Reproductive SystemOvariesProduce ova, estrogen, and progesteroneMedulla ~ nerves and lymphatic and blood vesselsCortex ~ ovarian follicles Female SystemBackOvaries and Ovum FormationOogenesisPrimordial folliclesPrimary oocyteFollicular cells Primary oocyte stimulated to continue meiosisAt pubertyPolar bodySecondary oocyteOvum, if fertilized Released during ovulationInternal Accessory Organs – Female Fallopian tube – oviductInfundibulum and fimbriaeFringed, expanded end of fallopian tube near ovaryFunction to “catch” an ovum Muscular tube Lined with mucous membrane and ciliaPropels ovum toward uterusInternal Accessory OrgansInternal Accessory Organs – Female (cont.)UterusReceives embryo and sustains its developmentDivisions Wall ~ three layersVaginaExtends from uterus to outside body Rugae Wall ~ three layersInternal Accessory OrgansBackExternal Accessory Organs - Female Mammary glandsSecretion of milkStructuresNippleAreola Alveolar glandsExternal Genitalia – FemaleVulva Labia majora Adipose tissue and skinForm the mons pubisLabia minoraVascular folds of skin Form hood over clitorisVestibule Bartholin’s glandsClitorisContains female erectile tissueRich in sensory nervesPerineum – between vagina and anusFemale SystemErection, Lubrication, and Orgasm Nervous stimulation Clitoris becomes erect Bartholin’s glands activateVagina elongatesOrgasmSufficient stimulation of clitorisWalls of uterus and fallopian tubes contract to propel spermFemale Reproductive HormonesHypothalamus secretes GnRHGnRHAnterior pituitary releases FSH & LHStimulatesOvaries to produce estrogen and progesteroneEstrogen and progesterone are responsible for development of secondary sex characteristicsReproductive CycleMenstrual cycle Regular changes in uterine liningShedding of lining and bleedingMenarche – first menstrual period Menopause – termination of cycle due to normal aging of ovariesFollicular cellsbecomecorpus luteum,which secretesprogesteroneAnterior pituitaryreleases FSHUterine lining thickensOvarian folliclematures and secretesestrogenThen releases LHTriggers ovulationLining more vascular and glandularWithout fertilization Corpus luteum degenerates Estrogen and progesterone  levels fall Uterine lining breaks down – menses starts Cycle begins again with release of FSHReproductive Cycle (cont.)Apply Your KnowledgeTrue or False: ___ The ovaries only produce estrogen.___ Ovulation is the process of ovum formation.___ The fallopian tube is also called the oviduct.___ The endometrium is the outer layer of the uterine wall.___ Alveolar glands produce milk.___Oxytocin induces the alveolar glands to deliver milk through the nipples.___ Menarche is the termination of the menstrual cycle.___ Menopause occurs due to normal aging of the ovaries.FTFTFFTFANSWER:firstlactiferous ductsinner layerOogenesis produce estrogen and progesteroneYIPPEE!Common Diseases and Disorders of the Female Reproductive System (cont.)Disease/DisorderDescriptionEndometriosisTissues of uterine lining grow outside of the uterusFibrocystic breast diseaseAbnormal cystic tissue in the breast; size varies related to menstrual cycleFibroidsBenign tumors in the uterine wallOvarian cancerMore deadly than other types; detection difficult and often spreads before detectionCommon Diseases and Disorders of the Female Reproductive SystemDisease/DisorderDescriptionBreast cancerSecond leading cause of cancer deaths in womenCervical cancerGenerally slow to develop; Pap smear detects abnormal cervical cellsCervicitisInflammation of the cervix usually due to an infectionDysmenorrheaCondition with severe menstrual cramps that limit normal activitiesDiseases and Disorders of the Female Reproductive System (cont.)Disease/DisorderDescriptionPremenstrual syndrome (PMS)Collection of symptoms occurring just before a menstrual periodVaginitis/ vulvovaginitisInflammation of the vagina or inflammation of vagina and vulva; both associated with abnormal vaginal dischargeUterine (endometrial) cancerMost common in post-menopausal women; causes about 6% of cancer deathsApply Your KnowledgeMatching: ___ Inflammation of the cervix A. Dysmenorrhea___ Cancer common in post-menopausal women B. Cervical cancer___ Develops slowly; detected by Pap smear C. Fibroids___ Uterine tissue grows outside uterus D. Breast cancer___ Second leading cause of cancer death in women E. Cervicitis___ Severe menstrual cramps F. Endometriosis___ Benign tumors in the uterine wall G. Uterine cancerGFDCBAEANSWER:GoodJob!PregnancyCondition of having a developing offspring in the uterusFertilizationSperm penetrates cell membraneZona pellucida becomes impenetrableZygote Union of ovum and sperm nuclei46 chromosomesThe Prenatal PeriodZygote – undergoes rapid mitosis Morula – ball of cells BlastocystImplants in the endometrial wallInner cell mass becomes the embryoOthers plus cells from uterus form the placentaFormation of Placenta Amnion Umbilical cord Yolk sack Internal organs and external structuresThe Prenatal Period (cont.)Embryonic period Inner cell mass organizes into the primary germ layerEctodermMesodermEndodermThe Prenatal Period (cont.)Fetal period – fetus Rapid growth5th month Skeletal muscles activeGrowth rate slows6th month – gains weightLast 3 months – fetal brain cells rapidly divideGI and respiratory systems last to develop Fetal CirculationPlacenta and umbilical blood vessels – exchange nutrients, oxygen, and waste productsUnique differences Foramen ovale ~ bypass lungsDuctus arteriosus ~ between pulmonary trunk and aortaDuctus venosus ~ bypasses liverHormonal Changes During PregnancyHuman chorionic gonadotropin (HCG) Secreted by embryonic cellsMaintains the corpus luteumEstrogen and progesterone Secreted by corpus luteum and placentaStimulate uterine lining to thickenInhibit release of FSH and LH from anterior pituitary glandHormonal Changes During Pregnancy (cont.)Relaxin Inhibits uterine contractions Relaxes ligaments of pelvisLactogen – stimulates enlargements of mammary glandsAldosterone –increases sodium and water retentionParathyroid hormone (PTH) – blood calcium levelsApply Your KnowledgeWhat are the primary germ layers and what tissue develops from them?ANSWER: The primary germ layers are the: Ectoderm – nervous tissue and some epithelial tissue Mesoderm – connective tissue and some epithelial tissue Endoderm – epithelial tissue onlyRight!The Birth ProcessBegins when progesterone levels fallProstaglandins stimulate uterine contractionsUterine contractions stimulate release of oxytocinOxytocin stimulates strong uterine contractions The Birth Process (cont.)Dilation EffacementLasts 8 – 24 hoursExpulsion or parturition Actual birth stageMay take 30 minutes or lessPlacental stage Blood vessels constrictPlacenta separates from uterine wall and is expelledThe Postnatal PeriodSix-week period Neonatal period – first four weeksNeonate adjusts to life outside uterusMilk production and secretionProlactinOxytocinProduction continues as long as breast-feeding continuesApply Your KnowledgeWhat are the three stages of the birth process and what occurs during each?ANSWER: The three stages are: Dilation – the cervix thins, softens (effacement), and dilates to approximately 10 cmExpulsion – also called parturition; the actual birth stagePlacental stage – placenta separates from uterine wall and is expelledImpressive!Contraception MethodDescriptionCoitus interruptusPenis is withdrawn from vagina before ejaculation; not a reliable methodRhythm methodRequires abstinence around time of ovulation; not a reliable methodMechanical barriersPrevent sperm from entering female reproductive tractChemical barriersDestroy sperm in the female reproductive tract; primarily spermicides; often used with mechanical barriersContraception (cont.)MethodDescriptionOral contraceptivesBirth control pills; prevent ovulation by preventing LH surgeInjectable contraceptivesPrevent ovulation and alter lining of uterus to prevent implantation of blastocystInsertable contraceptivesRing inserted vaginally and removed at the beginning of the 4th week to allow menstruationContraceptive implantsSmall rods of progesterone implanted beneath skin; prevent ovulationContraception (cont.)MethodDescriptionTransdermal contraceptivesContraceptives in the form of a patch; applied weekly for 3 weeks; not used the 4th week to allow menstruationIntrauterine device (IUD)Small, solid devices placed into uterus by MD; prevents implantation of blastocystSurgical methodsTubal ligation – fallopian tube is cut and tiedVasectomy – vas deferens is cut and tiedApply Your KnowledgeANSWER: The rhythm method is not as effective as other birth control, because it is sometimes difficult to tell when ovulation occurs.Your patient has just been told that she is pregnant, but she does not understand why she could get pregnant. She states, “ I have been very careful in using the rhythm method of birth control.” What patient teaching would you do to assist her to understand?Good Answer!InfertilityInability to conceivePrimary Secondary Causes 15% unknown35% male-related problems50% female-related problemsInfertility (cont.)Some male-related factorsImpotenceRetrograde ejaculationLow or absent sperm countDecreased testosteroneSome female-related factorsPelvic inflammatory diseaseNo ovulation or menstrual cycleEndometriosisOlder than 40 years Infertility (cont.)Tests Semen analysisMonitoring of morning body temperatureBlood hormone measurementsEndometrial biopsyUrine analysis for LHHysterosalpingogram LaparoscopyInfertility (cont.)TreatmentsSurgical repair of abnormalitiesFertility drugsHormone therapiesArtificial inseminationIn vitro fertilization Use of surrogateApply Your Knowledge___ Retrograde ejaculation___ Mumps infection___ Inadequate diet___ Scarring from STDs___ Pelvic inflammatory  disease___ Hormone imbalances___ Use of some  medications ___ Being over 40 years  oldIndicate whether each cause of infertility is male-related (M), female-related (F), or both (B).BFFFFMMMANSWER:Very good!Sexually Transmitted Disease Infections Occurring in Both SexesSTDCause AIDSHIV virus causes AIDSChlamydiaCaused by bacterium Chlamydia trachomata.; most commonly reported; often no symptoms in female Genital wartsCondyloma acuminat; caused by HPV; not everyone infected has symptomsGonorrhea Bacterial cause: Neisseria gonorrhoeaSexually Transmitted Diseases (cont.)STDCause Herpes simplexViral cause: type II commonly known as genital herpesPubic liceParasitic infestation; commonly called crabs; Pediculosis pubisSyphilisBacterial cause: Treponema pallidum; decreasing in women but increasing in homosexual malesTrichomoniasisProtozoan: Trichomonas vaginalisApply Your KnowledgeMatch:___ Most commonly reported STD in the U.S.___ Two types; both caused by a  virus ___ Crabs___ Increasing incidence in  males___ Common bacterial STD; can also grow in mouth___ Caused by HPV virus FECABDANSWER:SUPER!GonorrheaGenital wartsSyphilisChlamydiaPubic liceHerpes simplexIn Summary32.1 The organs of the male reproductive system include the testes, responsible for sperm and hormone production; the accessory organs of vas deferens, seminal vesicles, prostate, and bulbourethral glands; scrotum; and penis. 32.2 The diseases of the male reproductive system vary widely between simple inflammation and cancers. In Summary (cont.)32.3 The organs of the female reproductive system include the ovaries, fallopian tubes, uterus, and vagina. The external accessory organs include the mons pubis, labia majora and minora, clitoris, urethral meatus, vaginal orifice, Bartholin’s glands, perineum, and mammary glands.32.4 The diseases of the female reproductive system vary widely between simple inflammation and cancers. In Summary (cont.)32.5 Fertilization occurs with the union of a sperm cell and an ovum, usually within the fallopian tubes. The fertilized ovum, now a blastocyst, implants in the endometrial wall of the uterus. The embryonic period occurs from week 2 through week 8 of the pregnancy; the fetal period is from week 9 through delivery.In Summary (cont.)32.6 The birth process ends pregnancy and occurs in three stages: Dilation (effacement), expulsion (parturition), and placental stage (afterbirth).32.7 Some of the contraceptive methods include coitus interruptus; barrier methods; chemical barriers; oral contraceptives; injectable, implantable, and insertable contraceptives; and intrauterine devices. In Summary (cont.)32.8 The causes of infertility are varied, with about 15% of infertility from unknown causes. There are a number of infertility tests and treatments; the treatment plan depends on the reason for the infertility.32.9 There are many sexually transmitted infections, all passed between sexual partners (both heterosexual and same-sex partners). The reproduction of mankind is a great marvel and mystery. ~Martin LutherEnd of Chapter 27