This document provides an overview of human reproduction for both males and females. It describes the internal and external anatomy of both the male and female reproductive systems. For females, it explains the menstrual cycle, hormones involved, ovulation and how fertilization occurs if the egg is fertilized by sperm. For males, it describes sperm production and ejaculation. If fertilization is successful, it describes the process of implantation and early fetal development. It also briefly discusses birth, breastfeeding and the possibility of twins.

1. Human Reproduction

2. • THIS POWER PONT PRESENTATION HAS
BEED ALTERED AND MODIFIED FOR
EDUCATIONAL PURPOSES THE ORIGINAL
PRESENTATIONS CAN BE FOUND ON THE
LINKS AT THE END OF THE PRESENTATION

3. Battle of the sexes!!!
• Are males and
females all that
different?
• Well…..
• Yes
• And
• No!

4. Anatomy
Male Female

5. Similarities
• 2 pouches
• Testicles
• Ovaries
• Start out inside body
• Testicles “descend” before birth
• Fetus begins with “starter parts” that could
develop into either gender.

6. Around 7th
Week…
• Baby’s body is “told” by DNA to become either
male or female.
• “Unused” parts disintegrate
• “Used” parts continue development
• (see overhead)

7. Male or Female???
• DNA determines baby’s gender
• XX = Female
• XY = Male
• Depends on which egg & sperm get together.
• Father determines baby’s gender.

8. Anatomy – similarities
Function – VERY different!
• Male
• Uncomplicated
• Produce sperm
• 2-4 MILLION every day
• Female
• Very
Complicated!
• One egg
• Once a month
• Careful
coordination of
hormones & body
• Timing perfect!

9. Females
• Ovaries
• 2 pouches
• Contain ova
• Born with all of her eggs (~ 400,000)
• Use up ~500
• Won’t run out!
• Ovulation
• One egg released from ovary to oviduct (fallopian
tube)

10. Internal reproductive:
• Vagina
• Cervix
• Fallopian tube
(uterian tube/oviducts)
• Fimbrae
• Ovary
• Uterus
- Endometrium
- Myometrium
- Perimetrium
cervix
vagina
fimbriae
uterine tube
ovary
uterus
endometrium
myometrium
perimetrium

11. Fimbrae & Fallopian Tube

12. Oogenesis in the Ovary

13. Oogenesis
Ovary- contains 400,000 oocytes; release
about 500 in a lifetime
• Ovary- under influence of FSH. The
follicles mature every 28 days
• Primary follicle produces estrogens
• And primary oocyte completes its 1st
division produces 2ndary oocyte and
polar body

14. Oogenesis
• Aprox 1/2 way through the 28 day cycle the
follicle reaches the mature Vesticular or
Graffian follicle stage.

15. Oogenesis
• Estrogen levels rise and release LH and FSH
and triggers ovulation.

16. Oogenesis
• The 2ndary oocyte travels down the uterine
tube to the uterus.
• If fertilized by sperm, it will produce a zygote
Ovum in uterine tube

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

19. 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

20. 28-Day Cycle (average)
• Three Stages
1. Tear Down
2. Rebuild
3. Extra nutrients/blood for potential baby
• No Baby?
• Back to #1

21. Chemicals (hormones)
• Regulate events in the body
• Estrogen
• Progesterone
• LH (leuteinizing hormone)
• FSH (follicle stimulating hormone)
• Many others

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

23. ~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

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

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

27. Birth Control Pills
• “Trick” body into thinking it’s pregnant
• Extra hormones
• No ovulation occurs
• No ovulation = no egg = no fertilization = no baby!
• No hormones taken for 7 days = menstruation

28. 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
• Vasectomy
• Cut/tie off tube – sperm can’t get out!

29. Testes

30. Male Reproductive System

31. Male Reproductive System

32. External structure of the
penis:
• glans penis
• prepuce (foreskin)
• There is no verifiable
health benefit to
circumcision.

33. Circumcision
foreskin glans penis urethral opening
suturesshaft
corona

34. Semen
• Contains
• 300-500 million sperm
• Sperm food
• pH buffers
• Allows sperm to survive for a couple of days
inside female’s body (hostile environment)

35. What is sperm?
• Then…
• Used to think it was a tiny human
inside each cell
• Spermists vs. Ovists

36. Now…
• Contains Several
Parts:
• Head
• Chemical to dissolve
egg goo
• Dad’s genetic
information (DNA)
• Mitochondria
• Energy
• Tail
• Swimming

37. Prostate Gland
• Adds non-sperm stuff to semen
• pH buffers
• Nourishment
• Cancer very common
• Slower-growing (usually)
• Surgery for removal

38. Bulbourethral gland
• Adds lubricant to aid travel of semen through
the urethra

39. Conception/Fertilization

40. Conception/Fertilization
• 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 female’s white blood cells
• Acidic environment
• Current

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

42. Zygote begins development
Time Lapse
Development

43. Implants in uterine lining
• Endometrium= outer lining of uterus
• Becomes placenta
• Uses mother’s nutrients
• Continues development

44. 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

46. Fetal Dev (cont’d)
• Umbilical Cord
• Blood vessels from placenta to baby
• Mom’s & baby’s blood do not circulate together!
• Can have 2 different blood types
• Diffusion

48. Ancient beliefs
• Wak Wak tree

49. 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

50. 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

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

52. Identical twins
• One zygote
• Splits in 2
• No one knows why!
• Completely random =
does NOT run in families
• Same exact DNA
• Nature’s clones

53. 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

54. 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.

56. REFERENCES
Human reproduction .Accessed
from:http://www.iteachbio.com/.../
Reproductive%20System/Human
%20Reproductio...
%E2%80%8E
.Accessed:06/03/2014
27 REPRODUCTION.ACCESSED
FROM:http://www.wcc.hawaii.edu
/.../Marieb%20ZOOL
%20142%20%20PPT/027%20...%
E2%80%8E

57. http://www.slideshare.net/promnqobi/human-
reproduction-completed