subject: Fertilization Process - The Uphill Battle Of A Sperm [print this page] Of the entire cycle of life, probably one of the most dramatic and miraculous steps is the fertilization process. Shared by all life on the planet, the only way that life continues is through the actual act of fertilization. In human beings and other mammals, fertilization is the singular event that kicks off a pregnancy and restarts the cycle of life. In human reproduction this is known as the moment of conception, and it is considered both miraculous and somewhat mysterious, as it is not readily observable. Though there have been some documentaries that have been filmed, which allow people to witness the actual process of fertilization, in day to day life, people cannot know whether fertilization has taken place until several weeks have passed.
Before a pregnancy begins, the fertilization process starts, with an egg being expelled from the ovaries of a woman, when it becomes ripe. For weeks before this event, which is known as ovulation, the woman's uterus has been forming a rich lining which is well suited for supporting a fertilized egg. When the egg is released from the ovary, it begins to travel down the fallopian tube, which connects the ovaries to the uterus. Through the process of intercourse, sperm is released into a woman's body in the form of semen which is ejaculated by a man into the vaginal canal.
Once sperm has entered the vaginal canal, it travels through the cervical lining, up through the uterus and into the fallopian tubes, in search of the egg. It is interesting to note that when a man ejaculates, he releases literally millions of sperm, but only one will successfully reach and fertilize the egg, causing pregnancy. The vagina and uterus are a hostile environment to the sperm and many sperm will not survive the journey. Many sperm will also enter the wrong fallopian tube and ultimately die there.
Once the sperm have entered the correct fallopian tube, they will travel along until they find the egg. Each sperm will then begin working its way into the egg. Only one sperm will successfully break through and fertilize the egg, causing pregnancy. This must happen within 48 hours of the sperm being ejaculated into the vaginal cavity. Once fertilized, the egg will travel the rest of the way down the fallopian tube and into the uterus, where it will implant itself in the rich lining.
