1 250 million sperm enter vagina 99 percent die within 30 minutes
60,000 sperm remain and must navigate through the cervix. The obstacle they have to get through is the mucus it produces to block off intruders. S
approximately 3,000 sperm remain and navigate through the uterus to the fallopian tube. Muscular contractions lead the sperm to the right way.
Fertilization, Implantation (Uterus)
Doorway to the fallopian tube, sperm must show right swimming characteristics to pass through.
10-30 sperm remain. Once inside sperm are safe from attack by leukocytes. Sperm are provided with nourishment once in here.
The remaining sperm must attempt to find the egg at the upper end of the fallopian tube. Egg releases chemicals so the sperm can move faster. Zygote travels dow the fallopian tubes toward the uterus, cells begin dividing. 5 days later the embryo breaks out of the protective shell and implants the wall of the uterus and begins growing.