Psychology 2075 Study Guide - Couvade, Breech Birth, Breast Pain
Document Summary
On about day 14 of an average menstrual cycle the woman ovulates. The egg is released from the ovary into the body cavity. Typically it is then picked up by the fimbriae and enters the fallopian tube. It then begins a leisurely trop down the tube toward the uterus, reaching it in about five days if it has been fertilized. The conception occurs in the outer third of the fallopian tube. As they approach, a chemical secreted by the egg attracts the sperm to the egg. A thin, gelatinous layer called zona pellucida surrounds the egg. Sperm swarm around the egg and secrete an enzyme called hyaluronidase (produced by the acrosome located in the head of the sperm). This enzyme dissolves the zona pellucida, permitting one sperm to penetrate the egg. The fertilized egg, called the zygote, continues to travel down the fallopian tube. About 36 hours after conception, it begins the process of cell division.
