1. Pregnancy & Menstruation

2. Menstrual Cycle once a month: 1 egg is released
if the egg is not fertilized, it passes through the body and exits
ends with menstruation
lining of uterus is shed
blood helps facilitate removal

3. Menstrual Cycle
if the egg is “fertilized”, pregnancy begins instead of menstruation

4. Fertilization Sperm and Eggs
have half the chromosomes of a normal cell, “haploid”

6. Structure of Human Sperm
The head contains the HAPLOID nucleus with 23 chromosomes.
The front of the head (acrosome) has chemicals that allow sperm to enter the egg

7. The mitochondria is located in the middle section and provides the sperm with energy.
The whip-like tail propels the sperm

8. The Relative Size of Sperm and Egg
The egg is larger than the sperm
because it contains many nutrients to be
used once the egg is fertilized.

9. Structure of Human Egg
Support

10. The Structure of the Human Egg
The egg has a haploid nucleus The egg has an outer barrier (Zona) that prevents more than one sperm from entering. It also has nutrient-producing support cells that surround the egg cell.

11. Fertilization Sperm must swim to egg
If can get through outer layer of egg:
the two nucleus’ fuse,
making 1 cell with 2 half sets of chromosomes (or 1 full set!)
this new, full cell: “zygote”

12. Development Fetus: “unborn baby” Baby: after birth Embryo Zygote
2+ cells
Zygote
One cell
Fetus
8+ weeks old
Abortion Question – when/what is aborted and removed.
Fetus: “unborn baby”
Baby: after birth

13. Pregnancy 40 weeks, from fertilization
broken into 3 sections, “trimesters”

14. First Trimester fertilization to end of 3rd month
embryo attaches to wall of uterus
sac forms around, fills with “amniotic fluid”
fluid supports & protects embryo/fetus
placenta starts to form

15. Second Trimester 4th month to end of 6th month fetus grows A LOT!
Can tell gender, with
ultrasound

16. 3rd Trimester organs function properly brain rapidly develops
final developments
happen for baby!
before birth:
fetus turns, so head is
pointing down

17. To Do’s Words: - amniotic fluid -placenta menstruation -fertilization
zygote embryo
fetus baby
testes penis
seminiferous tubules urethra
ovary vagina
uterus oviduct