2Male Reproductive System ObjectivesDescribe location, structure, and function of the organs of the male reproductive system.Discuss the process of spermatogenesis in the testes.
3Organs of the Male Testes – produce sperm and secrete hormones System of ducts (epididymis, ductus deferens, ejaculatory ducts, and urethra) – transports and stores sperm, assists in maturationAccessory sex glands (seminal vesicles, prostate, and bulbourethral glands) – adds fluid to semenSupporting structures – scrotum and penis – delivery and support
6Organs Scrotum (bag) – supporting structure for testes Loose skin Internally scrotum is divided into two sacs – one for each testisLocation of testes is vital to sperm survival2-3 degrees below normal body temperatureIn cold – muscles pull the scrotum closer to the body to keep sperm warmIn warm – opposite occurs
7Organs Testes or testicles Epididymis Descend during 7th month of pregnancyWhere sperm are made during spermatogenesisEpididymisComma-shaped organ along the border of each testisSite of sperm maturation – sperm acquire motility and ability to fertilize (14 days)Stores sperm for up to several months
8Organs Ductus deferens or vas deferens Ejaculatory ducts Urethra Along border of epididymis and up around bladderPushes sperm during arousal toward the urethraAlso stores sperm for several monthsEjaculatory ductsEject sperm and seminal vesicle secretions before release of semenUrethraPassageway for urine and semen
9Organs Seminal vesicles Prostate Pouch like structures at base of bladderSecrete alkaline fluid with fructose, clotting proteins, prostaglandinsAlkaline fluid neutralizes female acidity in vaginaFructose is for ATP production in sperm for their swimClotting proteins help semen coagulate after ejaculationProstateDoughnut shaped, golf ball sized organSecrete antibiotic for bacteria in urethra or vagina
10Organs Bulbourethral glands or Cowper’s glands Secrete alkaline fluid into urethra that protects sperm from urineSecretes mucus for lubrication of external penis and urethra
11Semen Mixture of sperm and seminal fluid Seminal fluid from seminal vesicles, prostate, bulbourethral glandsContains mL of fluid with million sperm/mL20 million/mL or lower is considered infertileSlightly basic ( ); milky appearance, sticky consistencySeminal fluid provides sperm with nutrients, transportation, protection
12PenisContains urethra and passageway for ejaculation of semen and urineGlans penis – head of penisErection – result of increased blood supply to penile tissue
14Penis Circumcision – removal of foreskin Vasectomy Cleaner and decreases risk of infection or diseaseVasectomySterilization of malesPortion of ductus deferens is removedDucts are cut and tied with stitchesSperm production continues, but sperm cannot reach exterior of penis
15Spermatogenesis Takes 65-75 days Begins with spermatogonia (stem cells)Undergo meiosis – 4 spermatidsSpermiogenesisWhen spermatids become spermatozoa
16Review Describe the function/structure of the following: TestesEpididymisDuctus deferensEjaculatory ductsUrethraSeminal vesiclesProstateBulbourethral glandsScrotumPenisWhat is spermatogenesis?
17Female Reproductive System ObjectivesDescribe the location, structure, and functions of the organs of the female reproductive system.Discuss the process oogenesis in the ovaries.
18Organs of the Female Ovaries – produce eggs and hormones Uterine (fallopian) tubes or oviducts – transport egg to uterus, site of fertilizationUterus – site of implantation of fertilized egg, development of fetus, laborVagina – receives penis, passageway for childbirthExternal organs (vulva)Mammary glands – synthesize, secrete, and eject milk for newborn
21Organs Ovaries Uterine tubes (fallopian) or oviduct Paired glands, almond sizedProduceGametes (egg cells)Hormones (progesterone and estrogen, inhibin, relaxin)Uterine tubes (fallopian) or oviductExtend away from uterusProvide route for sperm to reach ovumTransports eggs and fertilized eggs to the uterus from the ovaryHave cilia at the ends to “coax” egg from ovaryFertilization occurs hereUp to 24 hours after ovulation – sperm can survive for 3 daysEgg enters uterus 6-7 days after ovulation
22Organs Uterus (womb) pear-shaped Pathway for sperm deposition into vagina to reach fallopian tubesSite of implantation for fertilized eggGrowth of fetus during pregnancyLaborSource of menstrual flow
24Organs Cervical mucus Vagina Water, glycoproteins, lipids, enzymes, saltsMore hospitable to sperm during ovulationHelps protect sperm on passage to uterusVaginaFibromuscular canalReceptacle for penisOutlet for menstrual flowPassageway for childbirth
25Organs Vulva - External genitals of female Mons pubis – adipose tissue, skin, hairLabia majora – two folds, covered by pubic hairLabia minora – two folds, underneath labia majora, no hairClitoris, glans – erectile tissue and nerves, sexual excitement in females
27Organs Mammary glands Breast Nipple – where milk emerges Areola – darkened area around nippleMammary gland – modified sweat glands
28Disease/Medical Ovarian cysts Uterine prolapse Fluid-filled sac in or on ovaryUsually noncancerous, can go away on their ownUterine prolapseWhen uterus is outside the vaginaOccurs with age, disease, traumatic vaginal delivery, difficult bowel movements, coughingCan be put back with surgery
29Disease/Medical Hysterectomy Episiotomy Removal of uterus Fetus stretches perenial regionPerformed to prevent tearingStraight, tearing is jagged
32Review What is the function/structure of: Describe oogenesis. Uterus OvariesFallopian tubesVaginaMammary glandsDescribe oogenesis.
33ObjectivesDescribe the hormones that are important to the reproductive cycle.Summarize female reproductive cycle.Describe various methods of birth control.
34Female Reproductive Cycle Ovarian Cycle – events in the ovaries that occur during and after the maturation of an oocyteMenstrual Cycle – changes in the endometrium (lining) of the uterus to prepare for the arrival of a fertilized ovum that will develop until birthFemale reproductive cycle includes both of these
35Hormones of Cycles Gonadotropin-releasing hormone (GnRH) Estrogens Secreted by hypothalamusStimulates release of FSH and LHStimulate release of egg from ovariesEstrogensSecreted by ovariesPromote development of sex characteristicsProgesteronePrepare and maintain endometrium for implantationPrepare mammary glands for milk secretion
36Hormones of Cycles Relaxin Inhibin Relaxes the uterus by inhibiting contractionsIncreases flexibility of pubic symphysisHelps dilate cervixInhibinSecreted after ovulationInhibits secretion of FSH and LH
39Summary Cycle is counted from 1st day of last period Menstruation lasts 4-5 daysProliferative phase (13 days)Endometrium fills will tissue and bloodOvulation occurs around day 14Secretory phase (10 days)If egg is fertilized, tissue stays to care for fetusIf egg is not, menstrual phase begins again
40Birth ControlOral contraceptives (the pill) – inhibits FSH and LH from being released, ovulation doesn’t occur, no egg for fertilization – close to 100% effective“morning-after-pill” – causes shedding of lining (induces period) to prevent implantationIUD – prevent implantation in uterus by changing liningSpermicides – kill sperm, more effective with use of condom or diaphragm
41Birth ControlBarrier methods – prevent sperm from getting into uterus (condoms, diaphragm); also helps protect against STD’sPeriodic Abstinence – couple learns “cycle” and abstains during that time
42Review Describe various methods of birth control. Describe the hormones that are important to the reproductive cycle.Summarize the reproductive cycle.