Timmy is playing a video game about the journey of the sperm. In the game, John and Susan are trying to get pregnant. They as a couple are financially and mentally stable, have prepared a room for a baby, and are ready to love the hell out of that little sucker. While Susan is ovulating, her and John plan on conceiving a child. The sperm has not left his testicles yet.
4: Fighting off the White Blood Cell Army
Approximately 250 million of John's sperm are released into Susan's vagina. Most of them die within 30 minutes. The sperm is destroyed by deadly acids that protect the vagina from pathogens.
5: Safe in the Fallopian Tubes/Fertilization
By Emily Sullivan & Breanne Crowley
Sperm must swim single file through tiny channels in the cervical canal. Most of them will die because they get stuck or lost in one of the thousands of pathways. 60,000 sperm are left in this stage.
6: Baby Time! (in 9 months)
3,000 sperm now remain. Sperm are attacked by Leukocytes (white blood cell army that is launched by the body's immune system.) The remaining sperm must search for the doorway to the Fallopian Tube.
10-30 sperm remain. They are now safe from Leukocytes. The Fallopian Tubes provide them with nourishment. The remaining sperm must attempt to find the egg at the upper end of the Fallopian Tube. As the sperm gets closer, they shed layers of protein to swim faster. The sperm that makes contact with the "outer coat" of the egg that has a bag of enzymes on its head that explodes which allows it to penetrate the egg. The 23 chromosomes of the sperm and the egg pair up once the sperm is inside.
The zygote travels down the Fallopian Tubes toward the uterus, cells begin dividing. Five days later, the embryo breaks out of its protective shell and implants in the wall of the uterus and begins growing.