Читать книгу Sex For Dummies - Pierre Lehu A., Dr. Ruth K. Westheimer - Страница 70

Females, from about the age of 12 to 50, release an egg every 28 days (or thereabouts because not every woman’s cycle is regular). If the egg meets a sperm that was among the 50 million or so placed there by a man during intercourse, a pregnancy begins. This process is called fertilization. A fertilized egg needs an inviting home where it can divide and subdivide until it becomes a baby. The designated nesting area is called the uterus. (Sometimes a fertilized egg winds up someplace else, which can cause serious complications.)

Although the egg doesn’t need much in terms of decorations on the walls, it does need a blood supply. So at the time of the month when a fertilized egg may mosey on by and attach itself, the uterus dolls itself up with plenty of blood in its lining that an egg would find quite dandy. But if no fertilized egg comes along and implants itself in the walls of the uterus, the uterus doesn’t need all that blood, and it sheds it through menstruation.