« PrécédentContinuer »
Cavum Uteri.-In comparison with the size of the organ, the cavity of the uterus is of small size owing to the great thickness of the uterine wall. In the body, the cavity is merely a narrow chink between the anterior and posterior walls, which are almost in contact (Fig. 1033). When, however, the uterus is opened from above downwards in frontal section of the organ, the cavity of the body has a triangular outline (Fig. 1032). The base of the triangle is directed upwards, and corresponds to a line drawn between the openings of the uterine tubes, while the apex is directed downwards towards the cervix. The sides of the triangle are convex inwards towards the cavity. The cavity of the body becomes continuous with that of the cervix by an opening called the orificium internum uteri (O.T. internal os uteri), which is a little smaller and more circular than the external orifice of the uterus. The cavity of the cervix, canalis cervicis uteri, or cervical canal, extends from the internal orifice of the uterus, where it joins the cavity of the body, to the external orifice, where it opens into the vagina. It is a somewhat spindle-shaped passage, which is narrower above and below than in its middle part; sections show also that its antero-posterior diameter is shorter than its transverse one, owing to an approximation of its anterior and posterior walls. In the body of
FIG. 1032.-A. THE POSTERIOR ASPECT OF THE UTERUS AND BROAD LIGAMENT (the broad ligament has
been spread out).
a, b, and c, the isthmus tube, the ligament of the ovary, and the round ligament of the right side cut short. B. DIAGRAMMATIC REPRESENTATION OF THE UTERINE CAVITY OPENED UP FROM ITS ANTERIOR ASPECT.
the uterus the walls of the cavity are smooth and even, but in the cervical canal the mucous membrane forms a remarkable series of folds, called the plica palmatæ (O.T. arbor vitæ uteri). These consist of an anterior and a posterior longitudinally directed fold or ridge, from which a large number of secondary folds, or rugæ, branch off obliquely upwards and laterally (Fig. 1032, B).
Connexions of the Uterus and its Relations to the Peritoneum.-In addition to the uterine tubes at its upper lateral angles, and the vagina below, the uterus possesses other important connexions. Some of these are simply peritoneal folds passing from the uterus to neighbouring structures; others contain fibrous connective tissue, or smooth muscle fibres.
The peritoneum covering the fundus of the uterus is continued down over the vesical surface as far as the junction of the body and cervix, where it leaves the uterus to be reflected on to the bladder, forming the utero-vesical fold, or "anterior ligament of the uterus." The peritoneal recess between the bladder and the uterus is called the excavatio vesicouterina, or utero-vesical pouch. Below the level of this pouch the anterior aspect of the cervix is connected by loose tissue with the posterior, or basal, part of the bladder. Posteriorly the peritoneum covers the whole of the uterus, except the small portion of the cervix which projects into the upper part of the vagina. The peritoneum covering the intestinal surface of the uterus is continued to such a depth that it invests a small portion of the upper part of the posterior wall of the vagina before it is reflected on to the rectum, to form the recto-vaginal fold (Fig. 1033). The deep pouch between the uterus and
vagina in front and the rectum behind is called the excavatio rectouterina, or rectouterine pouch of Douglas, and its entrance is bounded on each side by a crescentic peritoneal fold, which passes from the posterior surface of the cervix uteri to the posterior wall of the pelvis, and ends near the side of the rectum. These crescentic folds are called the plica rectouterinæ, or recto-uterine folds of Douglas, and each contains between its layers a considerable amount of fibrous and smooth muscular tissue. A few of these fibres, which are continuous with the uterine wall, pass backwards to reach the rectum and constitute the musculus rectouterinus; others are said to gain an attachment to the front of the sacrum, and form a utero-sacral ligament. In many cases the recto-uterine folds become continuous with one another across the median plane behind the cervix uteri, and form, in this position, a transverse ridge termed the torus uterinus. The recto-uterine pouch of the female represents the recto-vesical pouch of the male, and the folds which bound it on each side, namely, the recto-uterine folds, correspond to the sacro-genital folds (sometimes called posterior false ligaments of the bladder) in the male sex.
The peritoneum of the vesical and intestinal surfaces, leaving the uterus along each lateral border to reach the side wall of the pelvis, forms the broad ligament of the uterus.
The ligamentum latum uteri, or broad ligament, is a wide peritoneal fold which passes from the lateral border of the uterus to the pelvic wall, and contains between its layers several important structures (Fig. 1032). The plane of the medial part of the ligament is determined by the position of the uterus. When the uterus is normally placed, the ligament has an anterior surface which looks downwards as well as forwards, and a posterior one which looks upwards and backwards. Near its attachment to the pelvis the ligament is placed more vertically. The free edge of the ligament contains the uterine tube, and follows the course pursued by that structure. Thus, in the undisturbed condition of parts, it at first passes horizontally laterally towards the uterine extremity of the ovary, where it ascends to arch over the tubal pole of the ovary on its medial side. Owing to the course pursued by the uterine tube round the ovary, the broad ligament forms a kind of curtain over the gland, and the ovary lies in a little pocket formed by the broad ligament, to which the name of bursa ovarica is applied (Figs. 1028 and 1029). This bursa ovarica is not to be confused with the fossa ovarii, or depression on the side wall of the pelvis, against which the ovary is usually placed.
The various structures in connexion with the broad ligament are most easily demonstrated when the ligament is spread out as flat as possible.
The ovary is connected with the posterior layer of the broad ligament by a very short mesentery, called the mesovarium, which, passing to the hilum, encloses the ovarian vessels and nerves as they reach the ovary. The part of the broad ligament which slings the uterine tube is called the mesosalpinx. When the ligament is spread out, the mesosalpinx has the form of a narrow triangle, the apex of which is at the lateral angle of the uterus, while the upper side is formed by the uterine tube, and the inferior one by the ligament of the ovary and the ovary itself. The narrow base of the triangle is directed laterally. Between the layers of this part of the broad ligament are situated the ep-oöphoron (O.T. parovarium). and the par-oophoron (Fig. 1032). The part of the broad ligament below the level of the mesosalpinx is termed the mesometrium, and contains, especially in its lower part a considerable amount of fatty connective tissue, the parametrium, and unstriped muscle fibres. The ureter and the uterine vessels lie in the lowest part of the broad ligament where it joins the pelvic floor. The fibrous and smooth muscle tissue which lies in the lower part of the broad ligament, immediately below the uterine artery, forms what is known as the lateral cervical ligament of the uterus. It is continuous with the dense tissue surrounding the branches of the hypogastric artery, and in vertical antero-posterior section has a triangular outline near its attachment to the cervix uteri.
The highest part of the attached lateral portion of the broad ligament forms the ligamentum suspensorium ovarii or suspensory ligament of the ovary, and contains between its layers the ovarian vessels and nerves as they enter or leave the pelvis.
The ligamentum ovarii proprium, or ligament of the ovary, is a rounded fibrous
cord, of about one inch in length, which is attached by its lateral end to the uterine pole of the ovary, and by its medial end to the lateral angle of the uterus immediately below and behind the entrance of the uterine tube. This ligament, which is largely composed of unstriped muscle fibres continuous with those of the uterus, is enclosed in a slight fold derived from the posterior layer of the broad ligament.
The ligament of the ovary represents the upper portion of the gubernaculum which appears in the embryo.
The ligamentum teres uteri, or round ligament of the uterus, is a narrow flat band attached to the uterus just in front of, and a little below, the opening of the uterine tube. Near the uterus it contains numerous smooth muscle fibres, which are continuous with those of the uterus; more laterally it is composed chiefly of fibrous connective tissue. Lying in the anterior part of the broad ligament, it reaches the wall of the pelvis minor, and is then directed forwards and slightly upwards to cross the obliterated umbilical artery and the pelvic brim. After it has reached the pelvic wall its course is comparable to that of the ductus deferens in the male, and, like the latter, it leaves the abdomen to traverse the inguinal canal (Figs. 1028 and 1029). It finally ends in the subcutaneous tissue and skin of the labium majus. Its terminal part is composed of connective tissue only.
In some cases a small diverticulum of the peritoneal cavity can be traced accompanying the round ligament through the abdominal wall. This is called the processus vaginalis peritonei (O.T. canal of Nuck), and corresponds to the processus vaginalis of the male (p. 1294).
The round ligament of the uterus represents the lower portion of the gubernaculum testis which appears in the male embryo (see pp. 1294 and 1313).
Position and Relations of the Uterus. The position occupied by the uterus in the pelvis is not always the same, but varies with the conditions of the neighbouring organs. The lower cervical part is, however, much more firmly fixed in place than the body and fundus, which possess a considerable amount of mobility. Usually the level of the external orifice of the uterus will be found to correspond to that of a horizontal plane passing through the upper margin of the symphysis pubis. The uterus rarely lies exactly in the median plane of the body, but usually bends to one or other side, most frequently towards the right. The vesical surface of the uterus rests against the bladder, and follows the rising or falling of its superior wall as that organ becomes filled or emptied. When the bladder is empty the long axis of the uterus points forwards and upwards, and the organ is said to be in an anteverted position. Also, the long axis of the uterus is bent on itself where the body joins the cervix, and so the organ is said to be anteflexed. The anteflexion is due to the fact that the more rigid cervix is fixed, while the movable upper part of the uterus sinks forwards, following the bladder wall. With the empty condition of the bladder the angle formed between the long axis of the uterus and that of the vagina is about a right angle. When the bladder becomes filled, the anteversion and anteflexion of the uterus become less marked, owing to the body and fundus. being pushed backwards. Finally, if the rectum is empty and the bladder very much distended, the uterus is pushed so much backwards that the long axis of the organ may nearly correspond to that of the vagina. The uterus is then said to be retroverted. Superiorly a part of the peritoneal cavity intervenes between the vesical surface of the uterus and the bladder, but lower down the two organs are separated merely by a small quantity of connective tissue. The intestinal surface of the uterus looks into the pouch of Douglas, and is usually, like the fundus, in relation to some loops of the small intestine or pelvic colon. Laterally the uterus is related to the broad ligaments. The terminal parts of the ureters pass downwards, medially, and a little forwards on the lateral aspects of the cervix, but are separated from it by an interval of about three-quarters of an inch. The lowest part of the cervix is, as we have seen, enclosed within the cavity of the vagina.
On each side of the cervix uteri and upper part of the vagina there is an interval in which lie numerous large vessels. These are surrounded by loose fatty tissue, which is continued upwards for a considerable distance between the layers of the broad ligament. This loose tissue, which is of surgical importance, has received the name parametrium. ̧
THE FEMALE REPRODUCTIVE ORGANS.
The reproductive glands in the female are a pair of ovaries placed one on each side of the cavity of the pelvis. In connexion with each ovary is an elongated passage or tube-the uterine (O.T. Fallopian) tube-which leads to the uterus and opens into its cavity. There is no direct continuity between the ovary and the uterine tube, such as exists between the other glands of the body and their ducts, but the ova, when shed from the ovary, pass into the open end of the tube, and are thus conducted to the uterine cavity. The uterus is a hollow muscular organ which
FIG. 1028.-MEDIAN SECTION THROUGH THE FEMALE PELVIS.
Drawn for the most part from a model made from a dissection by Professor Edward H. Taylor.
occupies a nearly median position in the pelvis; it is joined by the uterine tubes above, and it communicates with the upper part of the vagina below. The ovum, having passed through the tube, reaches the cavity of the uterus, and in it, if fertilisation has taken place, the ovum undergoes its development into the embryo and foetus. The vagina is the passage which leads from the uterus to the exterior, and has its external opening behind that of the urethra, within the rima pudendi or uro-genital space. In connexion with the uro-genital space are a number of structures which are included under the term external genital organs, and which represent in the female the various parts of the penis and scrotum in the male. These are the labia majora and the mons Veneris, the labia minora, the clitoris, and the bulbus vestibuli. The larger vestibular glands, placed one on each side of the lower part of the vagina, are accessory organs of the female reproductive system, and are represented by the bulbo-urethral glands in the male.
The ovary is a solid body, flattened from side to side, and about the size and shape of a large almond. Its length is usually between one and one and a half inches, and the thickness from side to side between a quarter and half an inch. In the adult the ovary is placed against the side wall of the pelvic cavity, and is connected by peritoneal folds with the broad ligament of the uterus and with the side wall of the pelvis. The position occupied by the ovary within the pelvic cavity is fairly constant, although these ligaments do not hold the organ firmly fixed in any definite place.
In the ovary we recognise two extremities-a superior extremity, larger and more rounded, and an inferior extremity, somewhat pointed. The term extremitas
FIG. 1029.-SIDE WALL OF THE FEMALE PELVIS, showing the position of the ovary and its relation to the uterine tube. The pelvis has been cut in section parallel to, but at some distance from, the median plane.
tubaria is applied to the superior end of the ovary, as it is most intimately connected with the uterine tube; the term extremitas uterina is used with reference to the inferior extremity, since this part of the ovary is connected with the uterus by a fibrous cord, termed the ligament of the ovary. The flattened surfaces of the Ovary are called facies medialis and facies lateralis, and the borders separating them-margo mesovaricus or mesovarian border, and margo liber or free border. The free border is convex; while the mesovarian, which is straighter and narrower, is connected by a very short peritoneal fold, the mesovarium, with the posterior layer of the broad ligament of the uterus. The vessels and nerves enter the ovary at this mesovarian border, which is therefore often termed the hilum of the ovary.
Position and Relations of the Ovary. When the ovary occupies its most usual, or typical, position the long axis of the gland is vertical. Its lateral surface lies against the wall of the pelvis, and its medial surface looks medially towards the pelvic cavity. The peritoneum of the pelvic wall, where the ovary lies