PSY 0818 Lecture Notes - Lecture 1: Zona Pellucida, Fallopian Tube, Miscarriage
Document Summary
Union of a sperm cell and an ovum. Each ejacuate contains an average of 200 to 400 million sperm. Ovum secretes a chemical that attracts sperm. Fertilization normally occurs in a fallopian tube. Ovum is surrounded by zona pellucida which must be penetrated by sperm to fertilize it. Sperm secrete the enzyme hyaluronidase, which briefly thins zona pellucida, enabling penetration. Sperm carry either x or y sex chromosomes. Girls are produced from union of 2 x. Boys are produced from union of an x and a y. Y sperm appear to be faster swimmers. Ovum can be fertilized for 4-20 hours after ovulation. Sperm are most active within 48 hours after ejaculation. Male fetuses more likely lost in spontaneous abortion, which helps balance the sexes. Spontaneous abortion is the loss of pregnancy, often in the first month, and sometimes before the woman knows she"s pregnant. Analyzing urine or saliva for luteinizing hormone. Failure has persisted for more than a year.
