LIGAMENTS OF THE UTER'O'S.
These terms are applied to several dupli catures of peritoneum, containing variable quantities of fibrous and muscular tissue, which serve to connect together the uterus and its appendages and to limit the motions of these parts within the pelvis. They are dis tinguished as the broad, the round, the utero sacral, and the vtero-resical ligaments.
The broad ligament.—The fold of perito neum in which the uterus is contained, after investing the fundus and anterior and posterior walls of' the organ, passes off laterally in the form of a double lamina that extends from each uterine border horizontally outwards as far as the sides and base of the pelvis, to which it is attached. Thus a vertical septum is formed, which divides the cavity of the pelvis transversely into two chambers; the anterior and shallower one containing the bladder, the posterior and deeper holding the rectum and a portion of the small intestines. The uterus occupies the middle of the septum, while the lateral extensions of it form the broad liga ment of either side. Figs. 368. and 404.f., Attached to the upper border of the broad ligarnent are three folds, termed lesser wings. The central and superior of these, which is the largest, contains in its free falciform edge the Fallopian tube, and at its base a portion of the parovarium. It has been already described as the mesentery of the tube. The smaller pos terior fold invests the ovary together with its proper ligament ; while the third or anterior fold is inclined obliquely towards the body of the uterus, and constitutes the covering of the round ligament. Between the lanainw which form the principal or lower portion of the broad ligament, as well as within the aim, are found the blood-vessels, lymphatics, and nerves which supply the uterus and its appendages, together with a variable amount of fibrous and un striated muscular tissue that serves to connect the alminae together.
This structure should be regarded as a me sentery rather than a ligament of the uterus. It serves to invest the uterus and its appen dages with a common peritoneal covering, and to protect these parts and attach them to the pelvis, as the mesentery attaches the intestines to the spine ; while the interspace of the folds suffices for the conveyance of vessels and nerves. The resemblance to a mesentery is more obvious in the bicorned and intestiniform uterus of the mammalia generally, as well as of many other vertebrata in which it forms the mesometriunz.
The utero-sacral ligaments.—From the pos terior wall of the uterine neck two falciform folds of peritoneum proceed towards the rectum. These are most easily seen when the parts are stretched. Between them lies the depression of variable depth known as the retro-uterine pouch, or space of Douglas. 'When the peritoneum is removed, these fblds are seen to be occasioned by two correspond ing bands of fibrous tissue, extending from the substance of the cervix backwards towards the sacrum, to which they are attached. Their strength varies considerably in different sub jects ; so that when not much developed they. may be overlooked. The importance of these ligaments, or rather fibrous bands, has perhaps not been generally sufficiently appreciated.
From their position and connections it cannot admit of doubt that they are intended to re strain the motions of the uterus, — to prevent it from being forced upwards in the act of con junction, and especially to limit the descent of the organ in erect postures of the body.
The utero-vesical ligaments.— Opposite to the point of junction of the body and neck of the uterus, where the peritoneum is reflected forwards on to the bladder, are commonly observed two slighter lateral folds, containing bundles of fibrous tissue. These constitute the anterior or utero-vesical ligaments.
The round or sub-pubic ligament: ligamen turn rotundum, ligamentum uteri teres.— This ligament consists of a flattened chord or band of muscular and fibrous tissue, which, traced from below upwards, proceeds from the in ternal inguinal ring in a curved direction to wards the superior angle of the uterus on either side, where it is inserted in front of and a little below the commencement of the Fallopian tube. (Figs. 404. and 418.) The ligament of the right side is commonly shorter than that of the left : hence it hap pens that in pregnancy the uterus more often inclines to that side. According to Mr. Rainey*, the round ligament arises by three fasciculi of tendinous fibres : the inner one from the tendons of the internal oblique and transVersalis muscles near the symphysis pu bis ; the middle one, from the superior column of the external abdominal ring, near its upper part ; and the external fasciculus, from the inferior column of the ring, just above Gim bernat's ligament. From these attachments the fibres pass backwards and outwards, soon becoming fleshy : they then unite into a rounded chord, which crosses in front of the epigastric artery, and behind the lower border of the internal oblique and transversalis muscleF, from which it is separated by a thin layer c,f fascia continuous with the fascia transversalis, : it then gets between the layers of peritoneum forming the broad ligament, along which it passes backwards, downwards, and inwards to the point of insertion already described.
The round ligament is composed of smooth muscular fibre, derived from the uterus, and arranged in bundles, surrounded by connective tissue, of striated muscle, continuous with that of the abdominal parietcs, and of blood-ves sels, lymphatics and nerves.
The peritoneal covering of the round liga ment is occasionally prolonged in young sub jects at its lower part through a portion of the inguinal canal, where it forms the canal of Nuck. This is usually obliterated in adults, where the arrangement of the tendinous part of the round ligament just described serves to close the in ternal ring, and to prevent, in a great measure, the occurrence of inguinal hernia in the female. The persistence of' this canal probably leads to the abnormal descent of the ovary into the labium, constituting hernia of the ovary (see p. 574.) ;—an occurrence exactly comparable with the normal descent of the testis into the scrotum of the male.