Fig 1. The journey begins with millions of sperm cells that are released into the female reproductive tract during intercourse. The sperm cells gain their full ability to swim when they are ejaculated into the reproductive tract [ 1 ],[ 2 ]. Upon ejaculation, the sperm cells are enclosed in a fluid called seminal plasma or semen, which is a mix of fluids from the testes, seminal vesicles, prostate, and the bulbourethral glands.
Human fertilization is the union of a human egg and sperm , usually occurring in the ampulla of the fallopian tube. 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. The sperm plasma then fuses with the egg's plasma membrane, triggering the sperm head to disconnect from its flagellum as the egg travels down the Fallopian tube to reach the uterus.
Fertilization , union of a sperm nucleus , of paternal origin, with an egg nucleus, of maternal origin, to form the primary nucleus of an embryo. In all organisms the essence of fertilization is, in fact, the fusion of the hereditary material of two different sex cells , or gametes , each of which carries half the number of chromosomes typical of the species. The most primitive form of fertilization, found in microorganisms and protozoans, consists of an exchange of genetic material between two cells.