widely during delivery. In addition, it serves as an excretory duct for uterine secretions and menstrual flow.

The vagina is a fibro-muscular tube capable of great distention. The canal is approximately 9 cm long and extends from the uterus to the outside. The vaginal orifice is partially closed by a thin membrane of tissue called the hymen. The wall of the vagina also consists of three layers of cells.

Normal Pelvis

In addition to its function as the main weight bearing part of the mother’s body, It is also the bony base and outlet of the trunk through which the child must pass to be born. It is shaped like a funnel with a curved canal. The pelvis is made up of four bones. The sacrum forms the back wall of the pelvic canal. It is made up of five fused vertebrae to which the coccyx is attached at the base, and is ideally shaped as a triangle to transfer the body weight of the mother down to her legs. The sacrum is flanked on either side by the large hipbones, each of which is made of three bones fused together since puberty. These are the ilium (flank or side bones), ischium (buttock or sitting bones) and the pubis in front. The two pubic bones meet in front at the powerful joint, which is known as the symphysis pubis, so that