The document summarizes the process of human reproduction from conception through birth. It describes how DNA determines a baby's sex, the development of male and female anatomy, the menstrual cycle and hormones involved, fertilization, fetal development within the womb, stages of labor and birth, and breastfeeding. The reproductive system of both males and females is explained in detail, covering the production of eggs and sperm, as well as the journey from fertilization to birth over the course of a full-term pregnancy.

1. Human Reproduction

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

3. Male or Female???
DNA determines baby’s gender
XX = Female Chromosome
XY = Male Chromosome
Depends on which egg & sperm get
together.
Father determines baby’s gender by
contributing an X or Y. Mother can only
contribute an X.

4. 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!

5. 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
fallopian tube
Hyperovulation- more than one egg
released from ovary to fallopian tube

6. After Ovulation
Egg pushed along by cilia
Can be fertilized in the fallopian tube and is
viable for 12-24 hours
Few days travel time to arrive in uterus

7. Menstrual Cycle
Complex combination of 10-12
chemicals (hormones)
Usually one egg once a month
All about timing!!!
Sperm can live up to 5 days in the female’s body. An ovum is
only viable for 12 to 24 hours. A woman can get pregnant
anytime from about five days prior to ovulation to even
occasionally two days after, for a total of about seven days.
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

8. 28-Day Cycle (average)
Three Stages
1. Tear Down
2. Rebuild
3. Extra nutrients/blood for potential baby
No Baby?
Back to #1

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

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

11. ~Day 14
Ovulation = Egg released
Temp spikes slightly
Most fertile in next few days!
Able to get pregnant- while egg is traveling in the
fallopian tube.
Egg gets fertilized while traveling through oviduct.
Technically, ovulation takes place two weeks before the
onset of the next period.
Cycles can differ and women’s cycle length differs

12. If fertilized…
Zygote begins to divide as it travels
through fallopian tube
Implants into lining of uterus

13. If not fertilized…
Egg travels through the fallopian tube to
uterus
Exits body with blood and tissues
during menstruation

14. 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 (medical procedure)
Cut/tie off tube – sperm can’t get out!

15. Semen
Contains
300-500 million sperm
Sperm food
pH buffers
Allows sperm to survive for a couple of
days inside female’s body 3-5 days
(hostile environment)

16. Sperm….
Several Parts:
Head
Chemical to dissolve egg shell
Dad’s genetic information (DNA)
Mitochondria
Energy
Tail
Swimming / propulsion

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

18. Conception/Fertilization
Ejaculation
Release of 300-500 million sperm
Egg needs to be in the fallopian tube
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
Timing

19. Once egg is located…
Dissolve protective coating surrounding
the egg
One gets through – enters egg
Instant biochemical change in zygote
No more sperm allowed in

20. Zygote begins development
The united egg and sperm is called zygote.
Within 36 hours, while the zygote is still
traveling through the fallopian tube, it
begins to divide.

21. The Blastocyst
From the two-cell stage until about nine
weeks after fertilization, the growing
structure is called embryo. About 5 days
after fertilization, the embryo reaches the
uterus.
By this time it is made up of about 500
cells.

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

23. Healthy Pregnancy
Prenatal Care: monitoring tools
Proper nutrition
Prenatal vitamins
Exercise
Avoiding alcohol and drugs
Avoiding environmental hazards (x-
rays, lead, mercury, cat litter)

24. Fetal Development
Amniotic Sac: Soon after implantation, a
fluid filled bag of thin tissue develops
around the embryo.
The sac continues to grow in size as
the embryo grows.
Inside the sac is amniotic fluid. “water
breaking”

25. Placenta
• Lines part of the wall of the uterus
during pregnancy and nourishes the
embryo with substances from the
mother’s blood. (oxygen, nutrients, etc)
• Dangerous substances can pass
between mother to baby too. (alcohol,
drugs, chemicals)

26. Umbilical Cord
– About 25 days after fertilization, a cordlike
structure develops between the embryo and
the placenta.
– Blood vessels from placenta to baby
– Mom’s & baby’s blood do not circulate
together!
• Can have 2 different blood types
• Diffusion

27. Growing Fetus
• From the 3rd
month until birth the baby is
called a fetus.
• During the 3rd
to 6th
month, the fetus begins to move and
kick. (nervous system matures, sense organs develop,
and the fetus becomes sensitive to light and sound,
fetus alternates periods of activity and sleep)
• During the seventh to ninth month, the fetus continues
to grow and develop. The size of the body increases
and body fat accumulates.
• By 40 weeks, the fetus is ready to be BORN!

28. Stages of Birth
• Labor
• Contractions begin
• Cervix begins to dilate and efface
• Contractions every five minutes and
lasting 40 to 60 seconds
• Early labor ends around 4 cm dilated

29. Stages of Birth
• Transition & Delivery
• Cervix dilates from 8 to a full 10
centimeters
• This is the most intense part of labor.
• Contractions are strong, coming every
two and a half to three minutes or so
and lasting a minute or more
• Time to “push”

30. Stages of Birth
• Delivering the afterbirth
• Minutes after giving birth, your uterus
begins to contract again.
• The first few contractions usually
separate the placenta from your uterine
wall.
• Nurses gently push to help expel the
placenta

31. Breastfeeding
• Most nutritious option for baby
– Milk changes as baby grows
• Antibodies from mom create immunity for baby
• Can protect baby from allergies
• Can protect mother from postpartum depression
• Breastfeeding may reduce risk of breast cancer
• Studies have shown correlation between
breastfeeding and higher intelligence in baby
• Bond w/baby is stronger
• Helps Mom lose weight & uterus to shrink back

32. Full term
• Babies are considered full term at 37 weeks
• Pregnancy is typically 40 weeks (280 DAYS)
• Pregnancy is broken into trimesters
– 1st
– 1-3 months
– 2nd
- 3-6 months
– 3rd
-6-9 months
• Doctor’s appointments
– Start monthly
– Around 28 weeks- every 2 weeks
– @35 weeks- weekly