20I4 HUMAN ANATOMY. 



ments are below their pelvic attachments. Normally their insertions and origins lie 

 approximately in the same horizontal plane when the woman is erect (Penrose). 



The integrity of the levator ani muscle, ensuring a well-closed vaginal outlet, is 

 the most important factor in supporting the uterus within the pelvis. It keeps the 

 outlet forward under the pubic arch out of the line of abdominal pressure, gives it the 

 form of a narrow slit, preventing the protrusion of the pelvic viscera, and directs the 

 axis of the \aginal canal forward instead of directly downward, so that the intra- 

 abdominal pressure strikes the pelvic floor at a right angle ; and by aiding in main- 

 taining the vagina in its normal condition of a closed slit with its walls in contact, it 

 prevents disturbance of the forces which hold the uterus in place. If a laceration of 

 the perineum converts the vagina into an open air-containing tube, the equilibrium of 

 these forces is destroyed and prolapse often follows. In severe cases of prolapse the 

 ureters are so stretched that, at their vesical ends, their lumen is narrowed and 

 ureteral dilatation or hydronephrosis may result. 



Aiiterior and posterior flexions of the uterus occur at the isthmus, which is the 

 weakest point and is the junction of the larger and more movable portion — the body 

 — with the smaller and more fixed portion — the cervix. 



On account of the normal anteflexion of the uterus, it is not always easy to 

 decide in a given case whether the degree of anteflexion is normal or abnormal. 

 When it is abnormal the most important symptom is dysmenorrhoea, from obstruc- 

 tion of the canal by the flexion ; if irritability of the bladder occurs, it is probably 

 reflex in its origin. 



Anything which weakens the support of the uterus, or increases its weight, 

 tends not only to cause prolapse, but also to the production of retroflexion or retro- 

 versioti of the uterus, the first degree of prolapse being associated with some retro- 

 displacement. The uterus then loses its normal anteversion, and the intra-abdominal 

 pressure is brought to bear on its anterior surface, especially if the patient is either 

 confined too long in the supine position after labor, with the abdomen too tightly 

 bandaged, or if she leaves her bed too soon or undertakes any physical work. 



The uterus is larger and heavier than normal, as a result of imperfect involution ; 

 the uterine ligaments are lax ; the vagina and the vaginal orifice are relaxed, and 

 the support of the pelvic floor is consequently deficient ; the abdominal walls are 

 flabby and the retentive power of the abdomen is diminished. These are also the 

 causes that favor prolapse of the uterus ; in fact, a slight degree of uterine prolapse 

 usually accompanies such cases of retrodisplacement. A certain amount of retro- 

 version must always exist before the uterus can pass along the vagina. It must turn 

 backward, so that its axis becomes parallel to the axis of the vagina (Penrose). 



In the purely retroverted positions the uterus revolves on the isthmus as on a 

 pivot, so that as the fundus goes in one direction the cervix passes in the other. 

 Therefore, as the cervix is turned forward against the base of the bladder, the fundus 

 presses backward on the rectum, often producing reflex symptoms. 



The uterus may be found inclined to one side — more usually the fundus to the 

 left, and the cervix, on account of the presence of the sigmoid and rectum on the left 

 side, to the right. Unless extreme, such inclination is not to be regarded as patho- 

 logical. 



Between the layers of the broad ligaments is a quantity of loose adipose cellu- 

 lar tissue, the parametrium, separating the contained structures — those of the most 

 importance being the tubes and ovaries with their vessels and nerves — from one 

 another and from the serous membrane. This cellular connective tissue is continuous 

 with the surrounding subperitoneal areolar tissue of the pelvis, and is especially 

 abundant near the base of the broad ligaments. 



In pelvic cellulitis there is infection of this loose cellular tissue, usually through 

 the lymphatics and often puerperal in origin. It may follow other septic intrapelvic 

 conditions, especially salpingitis, but a simple cellulitis unaccompanied by tubal 

 inflammation is in the vast majority of cases due to infection through the uterus from 

 a septic endometritis. Because of the laxity of the tissue it may spread rapidly and 

 extensively in virulent cases. It may extend backward along the utero-sacral liga- 

 ments, then upward along the retroperitoneal tissue, as far as the kidneys. It may 

 pass forward and upward to the groin, where, should an abscess form, it may be 



