How does fertilization occur within the oviduct?

Fertilization in the fallopian (oviduct) occurs when a sperm cell meets and fuses with an ovum (egg) in the ampulla region of the oviduct. The sperm penetrates the zona pellucida of the ovum, the membranes fuse and the male and female pronuclei merge, forming a zygote. The newly formed zygote then begins to divide (cleavage) as it travels down the oviduct toward the uterus.