Under these circumstances, the position of the uterus relatively to surrounding parts M i 11 be in accordance with the accompanying sec tional diagram (fig. 423.), representing the pelvic contents. Here A represents the ute rus, B the bladder, and c the rectum, both of the latter being raoderately distended.
At such a time the uterus, supported be tween the folds of the broad ligament, which constitutes a moveable dissepiment, dividing the pelvis transversely into two unequal parts, and sustained by the parts attached to it around and below, lies with its fundus directed obliquely upwards and forwards, while the cervix or neck looks downwards, and very slightly backwards towards the orifice of the rectum. The relative heights of these several parts are determined by two lines : the one, a—a, drawn from the lower border of the symphysis pubis to the promontory of the sacrum ; the other, b—b, from the same point to the lower margin of the fourth sacral ver tebra. Upon the latter the cervix will rest at a point near the centre of the line. The di rection of the uterine body will be more con veniently shown by a third line, c—c, drawn through its axis. This line, if produced, will pass out of the pelvis upwards at a distance of -I" in front of the sacral promontory; and downwards, after traversing the posterior wall of the cervix, it will pass out about the centre of that wall, and inipinge upon the ex tremity of the coccyx. The lower portion or cervix of the uterus being curved upon the body in the manner hereafter described, the direction of its canal will be downwards, and will be represented by a line drawn nearly perpendicular to the horizon.
Fornz. —The uterus belongs to the class of hollow muscles, with which it is associated on account of its cavity and the muscular cha racter of its proper parietes. In many of the mammalia, the elongated form and general arrangement of the tissues gives to the uterus a resemblance to an intestine; while in man and the quadrumana, in whom it possesses a considerable degree of firmness and solidity, the shape more nearly resembles that of the urinary bladder.
The uterus has been compared to various objects, such as a flask, a little gourd or cala bash, a pear, or a truncated cone. There is
enough of similarity to these several objects, to excuse the comparison, yet the resemblance is not sufficiently close to render any of them an exact representative of that body ; but perhaps the flattened pear conveys the best idea of the uterine figure, although the pyri form outline is somewhat broken by the at tachment to its lateral borders of the parts usually termed appendages (fig. 368.). These should be, therefore, removed in order to dis play the proper boundaries of the organ (Jig. 421. and 431.).
Dimensions.— The uterus does not attain to its full development until after the establish ment of puberty. Previous to this period it remains but little altered from its infantine condition ; but as the period of puberty ap proaches, and about the time when the mam mw, which have also until then retained their infantine state, begin to enlarge, the uterus rapidly increases in bulk and weight. It then soon reaches the size which, if unemployed, it maintains through the rest of life, only wast ing, and becoming somewhat altered in figure by absorption of its tissues, as age advances ; or, if ernployed in the process of reproduc tion, then undergoing a degree of temporary enlargement unparalleled by any other growth of structure in man, and subsequently return ing, in part, though never entirely, to its for mer state.
The following are the average dimensions of the virgin or nulliparous uterus. The entire length from the centre of the fundus ( fig. 424 a), to that of the anterior lip b, which gives the longest diameter, is 2", 3m 7/”.
Of this one half usually belongs to the body, and the remainder to the neck or cer vix ; but the proportional length of either of these parts may exceed the other by l'"-2"'.
The greatest breadth of the organ is found opposite to the point of attachment of the Fallopian tubes. Here the transverse dia meter is 1", 3"/—; at the point of junction of the cervix with the body 10"; about the centre of the cervix 12'"; at the extremity of the cervix, opposite to the point of junction with the vaginal walls, 11"'-12'".