Presentation on theme: "Human Reproductive System"— Presentation transcript:
1Human Reproductive System Produces, stores, nourishes and transports functional gametes (egg and sperm).
21o Reproductive Organs = Gonads Gonads make gametes (sex cells) and the Sex Hormones.Ducts, accessory organs and glands assist gametesFertilization - union of sperm and egg = zygote.2o Reproductive Organs = External Genitalia
3Male Gonads Female Gonads Testes produce sperm and testosterone. Ovaries produces eggs, estrogen and progesterone.
4The Sex Chromosomes XX or XY Female Male 22 pairs of autosomal chromosomes +1 pair of sex chromosomes.The Sex ChromosomesXX or XYFemale MaleX chromosome has about 1,100 genes on it.Y chromosome has about 80 genes on it.
102o Sexual Characteristic Differences in anatomy and physiology between males and females = sexual dimorphism.CharacteristicMalesFemalesPattern of hair growthVoice (pitch)Muscle massBone growth/densitySex driveDistribution of body fatAggression
11Genetic and Phenotypic Sex If person with XY has testes that fail todifferentiate and secret hormones - Result?= genetic male, anatomical femaleIf person with XY has normal testosterone levels but target tissue lacks receptors - Result?= genetic male, anatomical female(testicular feminization syndrome)
13Klinefelters’s Syndrome Person has 47 chromosomes, the extra one is a Y, genotype = XXY= MaleReduced fertility, small testicles, enlarged breastTurner’s SyndromePerson has 45 chromosomes, the X or Y is missing, genotype = XO= FemaleUsually Infertile, short, immature sex organs at adolescence
14Triple-X Syndrome XYY Syndrome Women with 3X chromosomes - genotype is XXX“Super-females" or “Meta-females”.Taller, long legs, slender torsos, limited fertility. XYY SyndromeMales with extra Y chromosome - genotype is XYY. “Super-males“ often tall, high testosterone levels. Usually fertile. Both often unaware of chromosomal abnormality
16Male Reproductive Structures 1o Reproductive organ: TestesHeld ‘outside’ body in the scrotum.Dartos muscle wrinkles skin of scrotum.Cremaster muscle pulls testes closer to body.Cremaster Reflex.
17Ductus deferens – starts after tail of epididymis ~ 18 feet long~ 3 weeks to travel through- Head- Body- TailStores sperm, recyclesdamaged ones, site ofmaturation of spermDuctus deferens – starts after tail of epididymis
19Accessory Organs of the Male 1. Seminal vesicles2. Prostate glandAll secrete semen2. Bulbourethral glands1. Seminal VesiclesPaired glands - secretes 60% semen volume.Fibrinogen – converts to fibrin for clotting.Fructose – a monosacharide for energy.Prostaglandins – contract female tract.
202. Prostate Gland 3. Bulbourethral Glands Single gland - secretes 30% semen volume.Clotting proteins – to cause initial clots.Fibrolysin – to liquefy clots.3. Bulbourethral GlandsPaired glands (~5% semen volume).Alkaline mucus secretion (to neutralize).Lubricating properties.
21Semen Typical ejaculation releases 2-5 ml. Sperm count typically 50 – 100 million per ml.Sperm count below 20 million per ml, considered “infertile”.Sperm must be 2-3o F cooler than rest of body, hence kept ‘outside’ in scrotum.