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Human Reproduction. Human Reproductive System MaleFemale.

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Presentation on theme: "Human Reproduction. Human Reproductive System MaleFemale."— Presentation transcript:

1 Human Reproduction

2 Human Reproductive System MaleFemale

3 Male or Female??? DNA determines babys gender XX = Female XY = Male Depends on which egg & sperm get together. Father determines babys gender.

4 Male Uncomplicated Produce sperm 2-4 MILLION every day Female Very Complicated! One egg Once a month Careful coordination of hormones & body Timing perfect!

5 Females Ovaries 2 pouches Contain ova Born with all of her eggs (~ 400,000) Use up ~500 Wont run out! Ovulation One egg released from ovary to oviduct (fallopian tube)oviduct


7 After Ovulation Egg pushed along by cilia Few days travel time to arrive in uterusuterus CervixCervix – Opening between uterus & vagina Normally tiny At birth – muscles pull open (dilation) cervix to allow baby to pass through = Labor

8 Menstrual Cycle Complex combination of 10-12 chemicals (hormones) Usually one egg once a month All about timing!!! Uterus must be ready when egg gets there in case it was fertilized If no fertilization, tear down lining of uterus and rebuild for next month

9 28-Day Cycle (average) Three Stages 1. Tear Down 2. Rebuild 3. Extra nutrients/blood for potential baby No Baby? Back to #1

10 Chemicals (hormones) Regulate events in the body Estrogen Progesterone Many others

11 Day 1 First menstrual blood & tissue No baby = breaks down lining of uterus 5-7 days of blood/tissue exits body Pre-Ovulation

12 ~Day 14 Ovulation = Egg released Temp spikes slightly Most fertile in next few days! Able to get pregnant Egg gets fertilized while traveling through oviduct. Post-Ovulation

13 If fertilized… Zygote begins to divide as it travels through oviduct Implants into lining of uterus

14 If not fertilized… Egg travels through oviduct to uterus Exits body with blood and tissues during menstruation

15 Birth Control Pills Trick body into thinking its pregnant Extra hormones No ovulation occurs No ovulation = no egg = no fertilization = no baby!

16 Male Testes Produce 2-4 million sperm every day Outside body – why? Sperm like temps 1-2 cooler than body temp Vas Deferens Tube sperm travel through

17 Semen Contains 300-500 million sperm Sperm food pH buffers Allows sperm to survive for a couple of days inside females body

18 Now… Contains Several Parts: Head Chemical to dissolve egg goo Dads genetic information (DNA) Mitochondria Energy Tail Swimming

19 Prostate Gland Adds stuff to semen pH buffers Nourishment

20 Conception/Fertilization

21 Ejaculation Release of 300-500 million sperm Egg needs to be in oviduct Sperm to egg, not an easy task Go wrong direction : 2 paths – only 1 leads to an egg Get attacked by females white blood cells Acidic environment Current

22 Once egg is located… Dissolve protective goo surrounding egg One gets through – enters egg Instant biochemical change in zygote No more sperm allowed in

23 Gamete – Sex cell; sperm and ova Zygote – Cell formed after male and female gametes join immediately following fertilization

24 Zygote begins developmentdevelopment

25 Implants in uterine lining Blastocyst implants in outer lining of uterus Uses mothers nutrients Continues development

26 Fetal Development Anmion Membrane surrounding baby Contains amniotic fluid Breaks just before birth = water broke Amniotic Fluid The water – surrounding baby Buoyant cradle for baby Protection Free movement


28 Fetal Dev (contd) Umbilical Cord Blood vessels from placenta to baby Moms & babys blood do not circulate together! Can have 2 different blood types Diffusion


30 Birth Labor – muscles used to open cervix Baby flips upside down Head first! Feet first = Breech (bad) Cesarian Section (C-section) surgical removal of baby After baby is born mom delivers placenta (afterbirth) that detaches from uterus

31 Breastfeeding Most nutritious option for baby Milk changes as baby grows Antibodies from mom create immunity for baby Studies have shown correlation between breastfeeding and higher intelligence in baby. Bond w/baby is stronger

32 Twins/Multiple Births Two types Monozygotic From one egg Identical Dizygotic From two eggs Fraternal Not identical

33 Identical twins One zygote Splits in 2 No one knows why! Completely random = does NOT run in families Same exact DNA Natures clones

34 Fraternal Twins 2 separate eggs get fertilized with 2 different sperm cells More than one egg got released during ovulation Siblings Can be sisters Brothers Brother and sister Tends to run in families

35 Conjoined Twins Used to be called Siamese twins First well known case was in Siam Identical twins that never completely separated during development Sometimes can be separated, depending on what is shared.

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