Human fertilization is the union of a humanoid egg and sperm, usually occurring in the ampulla of the uterine tube. The result of this union is the production of a zygote, or fertilized egg, initiating prenatal development. Scientists discovered the dynamics of human fertilization in the nineteenth century.
The process of fertilization involves a sperm fusing with an ovum. The most common sequence begins with ejaculation during copulation, follows with ovulation, and finishes with fertilization. Various exceptions to this sequence are possible, including artificial insemination, In vitro fertilization, external ejaculation without copulation, or copulation shortly after ovulation. Upon encountering the ovum, the acrosome of the sperm produces enzymes which allow it to burrow through the outer jelly coat of the egg. The sperm plasma then fuses with the egg's plasma membrane, the sperm head disconnects from its flagellum and the egg travels down the Fallopian tube to reach the uterus.
In vitro fertilization (IVF) is a process by which egg cells are fertilized by sperm outside the womb, in vitro.
Famous quotes containing the word human:
“An indiscriminate distrust of human nature is the worst consequence of a miserable condition, whether brought about by innocence or guilt. And though want of suspicion more than want of sense, sometimes leads a man into harm; yet too much suspicion is as bad as too little sense.”
—Herman Melville (1819–1891)