The Uterus is 3 inches long, 2 inches wide at its broadest part, and its canal, including the cervical portion, is 2 inches long. It weighs about 1 ounce. It is composed of an upper expanded portion, the fundus, which ends at the level of the Fallopian tubes, a body, and a cervix, the junction of the two latter being occasionally marked externally by an isthmus, while internally there is a marked constriction at this point called the internal 0s. The cervix is about 1 inch long, and is invaginated into the vagina, so that its lower extremity, or external os, projects into the lumen of the vagina, and rests against its posterior wall. Thus the cervix is divided into supravaginal and vaginal segments. As the uterus is normally both anteflexed (angle of 120 degrees) and ante verted, it meets the vagina at a considerable angle, and the anterior vaginal wall therefore is shorter than the posterior.

The peritoneum covers the entire posterior surface of the uterus, except the vaginal portion of the cervix, and extends down over the posterior vaginal wall for about inch, forming Douglas's pouch (recto-vaginal or recto-genital pouch), after which it is reflected on to the rectum. In front it extends down to the junction of the body and cervix, and is then reflected on to the bladder. Laterally, the peritoneum extends out from the uterus in a double layer to the pelvic wall, constituting the broad ligament, while a small fold, called the sacro-genital fold, extends on either side from the posterior wall of the cervix to the side of the sacrum. These latter folds contain connective tissue and unstriped muscular fibres, and form lateral boundaries to Douglas's pouch. The uterus possesses a large range of movement, rising and falling according to the condition of the bladder, lying frequently a little to one side of the middle line, especially to the right, while on bimanual examination it may be moved through a considerable area without causing pain. As the cervix is more fixed than the fundus, the organ is frequently [lexed at the junction of these parts, and this flexion may be pathological and either anterior (anteflexion) or posterior (retroflexion). Retroversion of the whole organ may also occur, and likewise prolapse, or procidentia, where the organ descends through the vagina, which is turned inside out. the bladder frequently being directed downwards also, while the ureters become dilated in consequence of obstruction.

The cavity of the uterus normally is practically a triangular slit, whose apex is at the internal os, and whose basal angles correspond to the uterine ostia of the Fallopian tubes, while the cervical canal is spindle-shaped, wider at the centre than at either extremity, its mucous membrane being thrown into folds radiating upwards and outwards from the middle line in front and behind (arbor vitae). Inflammation of the uterus, metritis, frequently gives rise to pelvic cellulitis (parametritis), large abscesses occurring in the parametrium (q.v.), which, if untreated, may burst into the vagina or point above Poupart. The veins also may become affected, causing thrombosis, which may extend to the internal and even common iliac veins. In such cases swelling of the whole lower limb (phlegmasia alba dolens) occurs, and pyaemia may also be set up. Pelvic peritonitis (perimetritis) may be caused by extension of septic matter from the interior of the uterus along the Fallopian tubes.

Carcinoma frequently occurs in the cervix, spreads thence locally, involving the parametrium, ureters, bladder, and rectum, and later by the lymphatics. Fibro-myoma of the uterus is very common, and frequently attains a large size. Such tumours are classified according to their position as submucous, interstitial, and subperitoneal. Removal of the uterus may be accomplished through the abdomen (abdominal hysterectomy) or through the vagina (vaginal hysterectomy). In the former a median vertical abdominal incision is made, the broad ligaments ligatured and cut, the vagina cut through, and the uterus with its appendages removed. Care must be taken to avoid the ureters. In vaginal hysterectomy, the uterus is drawn down, the vagina divided, the bladder reflected, the broad ligaments drawn down and ligatured in detachments, and the uterus finally removed. Care is here especially necessary to avoid the ureters. Anteriorly, the uterus is related to the utero-vesical pouch of the peritoneum down almost to the cervix, and below this, for fully inch, is loosely attached to the posterior bladder wall by connective tissue ; posteriorly to the pelvic colon and small intestine, except when, the rectum and bladder being distended, these coils are displaced upwards and the rectum itself forms the postenor relation. Laterally, the uterus is related to the broad ligaments and ureters.

The iterine artery, from the anterior division of the internal iliac or one of its larger branches, descends on the lateral pelvic wall in front of the ureter, runs inward in the parametrium, crossing the ureter above the lateral vaginal fornix, and then turns up along the lateral border of the uterus, until, at the level of the ovarian ligament, it divides into its terminal branches. In its upward course the artery is very tortuous, and gives off many branches, which anastomose with those from the opposite side, and with branches from the ovarian artery, while its branch to the ovary anastomoses with the ovarian artery, and that to the round ligament with the deep epigastric artery. The uterus is also supplied by the uterino branch of the ovarian artery. The vessels in the uterine wall run transversely to the length of the organ. Ligature of the uterine artery has been done in the hope of arresting the growth of a uterine tumour. The uterine veins are thin-walled, and originate in cavernous spaces in the middle coat of the uterus, whence, emerging chiefly about the cervix, they unite with those from the vagina to form the ntero-vaginal plexus, which surrounds the ureter. Thence the blood is conveyed in two large veins, one on either side of the ureter, which ultimately unite and terminate in the internal iliac. During pregnancy these vessels are greatly increased in size. The lymphatics are arranged in three groups, in the mucous membrane, muscular coat, and subperitoneal tissue. They emerge chiefly about the level of the cervix, and join the glands about the bifurcation of the common iliac artery, while a few from the body of the uterus pass up with the ovarian vessels to the lumbar glands arranged along the aorta, and others pass to the inguinal glands along the round ligament. The nerve-supply of the uterus is from the second to fourth sacral nerves, while sympathetic fibres reach it from the hypogastric plexus running in the utero-sacral folds.