Organ in which the penis is inserted during coitus. Receives the ejaculate. It is the birth canal this the passageway the baby travels during birth. The top connects with the service (lower part of the uterus) and the bottom ends in the vaginal opening (Introitus). There are 3 walls of the vagina: the inner layer- the Vaginal Mucosa, the middle layer- is muscular, and the outer layer which forms a covering (the walls are extremely elastic and can expand. Become less elastic and less flexible with age). The nerve supply is mostly the lower 1/3 near Introitus - that part is sensitive to erotic stimulation. The inner 2/3s contains almost no nerve endings and is relatively insensitive except to feelings of deep pressure. Some women have G - Spots on the front wall of their vagina