Completely updated, this chart defines infertility; illustrates an ovum (egg) and spermatozoon (sperm); defines semen analysis; illustrates female internal genital organs and early cell division of a zygote; and describes and shows fertilization and implantation and blocked fallopian tubes. The chart lists common causes of infertility in both men and women. A pie chart graphic depicts the approximate distribution of common causes of infertility among men and women, including unexplained causes. The following causes of infertility are illustrated and described: For men: cryptorchidism, hypopituitarism, obstruction, and varicocele For women: polycystic ovarian syndrome (PCOS), pelvic adhesions, intrauterine fibroids, and endometriosis