C 405 Task 9 Reproductive
Cynthia Price
Fertilization
The process of fertilization occurs when sperm are introduced to an egg that has been released during ovulation. The timeframe for the egg and sperm to meet are crucial as sperm can survive for 4-6 days but the egg is only viable for 24-48 hours after release. When the egg is released from the ovary it is pushed into the fallopian tube by the fimbriae. It can take 4-6 days for this egg to travel to the uterus. The fallopian tubes are where most fertilization take place. During intercourse semen containing hundreds of millions of sperm are ejaculated into the vaginal vault. The force of the ejaculation and the sperm themselves carry them up to the uterus within minutes. The swimming sperm with the help uterine contractions manage to find their way to the fallopian tubes where they will meet with the egg. Fertilization begins with the sperm attempting to penetrate the egg. Many sperm attempt to fertilize but most fail. Usually the first one in wins. Once the first one has penetrated the cell and the nucleus is inside the egg, then a cellular reaction takes place to prevent polyspermy( or more than 1 sperm fertilizing). The other sperm start to fuse with the other cell membrane. The cell, now fertilized, will start to divide and multiply, this is known as cleavage. During the next 6 or 7 days as the cells reach the uterus and obtain nutrients from the uterine fluid this blastocyst will s...
