1. The more evolved the species, the better the success of reproduction.
Animal Reproduction
General Rule
The more evolved the species, the better the success of reproduction.

2. Gonads by Gametes “meiosis” (sex cells) Ovaries Eggs Testes Sperm
Sexual Reproduction
Gonads by Gametes
“meiosis” (sex cells)
Ovaries Eggs
Testes Sperm
(sex organs)

3. Meiosis- occurs only in testes and ovaries
Meiosis- occurs only in testes and ovaries. Body cells split to create 2 eggs or sperm, each with half the genes of the mom/dad.

4. Fertilization- union of sperm and egg to create a Zygote(fertilized egg).
Human males produce millions of sperm a day. Only 1 is needed to fertilize the female egg.

6. Human Reproduction
... a most amazing process!

8. Male Sex Organs Scrotum- cools testis
Testis- produce sperm
Scrotum- cools testis
Vas deferens- sperm tube (testis to penis)
Seminal vessicles- produce semen(fluid and glucose)

9. Male(cont.) Cowper’s gland- produces enzyme which activates sperm
Prostate gland- provides alkalinity (pH > 7)
Cowper’s gland- produces enzyme which activates sperm
Urethra- penis tube

10. Male (cont.)
Millions of sperm empty into the vagina and begin swimming randomly. Time is crucial because many die quickly and the hardiest will live for only 24 hours.

11. Female Sex Organs Ovaries- produce 1 egg/mo. (menstrual cycle)
Fallopian tubes(oviduct) - tubes connecting ovaries to uterus. 3 day trip for egg.
Uterus- womb(baby develops here)
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12. Female (cont.) Vagina- birth canal. Sperms begin their journey here.
Cervix- opening from vagina to uterus. Dilates from 0 cm. to 10 cm. at labor.
Vagina- birth canal. Sperms begin their journey here.

13. Female
Female sexual anatomy is physically less complicated, but physiologically more complicated due to hormones and the menstrual cycle.

14. Menstrual Cycle
Day 28
Day 1 ?? 14
FSH
FSH
LH+
Estrogen

15. Fertilization or Not? Day 28 If fertilized, womb is
prepared by increase of hormones(progesterone HCG, estrogen,etc.)
Day 28
If not, hormones shut off, uterus lining is released (menstruation); new cycle.

16. Development (Embryology)
... is the process from zygote to embryo(1st 3 months) to fetus(last 6 months) to birth by a form of cell reproduction called mitosis.
38-40 weeks

17. Mitosis- occurs in all body cells
Mitosis- occurs in all body cells. Cells make exact copies of themselves with all the genes.

18. After fertilization...
Cleavage
By mitosis, the zygote turns into a hollow ball of cells called a blastula

19. Differentiation
According to the genetic code, the ball of cells begins to form different tissues and organs.

20. Amniotic
Sac
Human
Embryo
5 weeks
Placenta

21. Many body parts are formed
at 8 weeks.

22. Bones were stained red in
this 11 week old embryo.

23. 3 months: Embryo to
Fetus

24. Uterus
Placenta
Umbilical cord

25. Embryo to Fetus
At three months, the embryo is fully developed(?) and weighs less than an ounce. It is now called a fetus and will mostly grow for the next 6 months.

26. Helping Organs
Placenta- softball size organ which attaches the fetus to the uterus. Transfers materials.

27. Helping Organs
Amniotic sac- fluid sac around the fetus. Protection.

28. Helping Organs
Umbilical cord- connects fetus to placenta. Carries blood.

29. Labor (avg. 12-24 hrs.) Contractions are started by a hormone.
Head is birthed 1st.
Mouth and nose are suctioned.
Umbilical cord cut.
Afterbirth(placenta and cord).

30. In humans, the real labor of parenting now begins and in most cultures lasts for many years!!