1. The Reproductive System: Methods of controlling human fertility. (3251

2. Stages of Pregnancy and Development
Fertilization
Embryonic development
Fetal development
Childbirth

3. Fertilization
The oocyte is viable for 12 to 24 hours after ovulation, which takes place usually around the 14th day of the female reproductive cycle (which averages about 28 days)
Sperm are viable for 24 to 48 hours after ejaculation
For fertilization to occur, sexual intercourse must occur no more than 2 days before ovulation and no later than 24 hours after
Sperm cells must make their way to the uterine tube for fertilization to be possible

4. Mechanisms of Fertilization
When sperm reach the oocyte, enzymes break down the protective layer of follicle cells around the oocyte
Once a path is cleared, sperm undergo an acrosomal reaction (acrosomal membranes break down and enzymes digest holes in the oocyte membrane)
Membrane receptors on an oocyte pull in the head of the first sperm cell to make contact
The membrane of the oocyte does not permit a second sperm head to enter
The oocyte then undergoes its second meiotic division to form the ovum and a polar body
Fertilization occurs when the genetic material of a sperm combines with that of an oocyte to form a zygote
See fertilization video:

5. The Zygote First cell of a new individual
The result of the fusion of DNA from sperm and egg
The zygote begins rapid mitotic cell divisions
The zygote stage is in the uterine tube, moving toward the uterus, where implantation of the embryo must occur (approx. day 7 after ovulation) must occur in order for the embryo (and later fetus) to develop.

6. Cleavage Figure 16.15 Fertilization Secondary oocyte Ovulation Uterus
Endometrium
Uterine tube
Blastocyst cavity
Inner cell mass
Trophoblast
Zygote (fertilized egg)
Early cleavage 4-cell stage
Early blastocyst
Late blastocyst (implanting)
Morula
Ovary
(a)
(b)
(d)
(e)
(c)
Figure 16.15

7. Developmental Stages Embryo—developmental stage until ninth week
Morula—16-cell stage
Blastocyst—about 100 cells
Fetus—beginning in ninth week of development
All organ systems are formed by the end of the eighth week
Activities of the fetus are growth and organ specialization
This is a stage of tremendous growth and change in appearance

8. Development of the Human Fetus
Table 16.1 (1 of 2)

9. Development of the Human Fetus
Table 16.1 (2 of 2)

10. Contraception (birth control)
There are many types of contraception widely used now days for family planning purposes.
Each method has its advantages and disadvantages.
No method of contraception is completely effective.
But, using contraception significantly lowers the risk of unplanned pregnancies.
Using two DIFFERENT types of methods together is much more effective.

12. Flow Chart of Events that Must Occur to Produce a Baby & Where Birth Control Acts
Figure (1 of 2)