THE UTERUS 513 



turn. Its ventral surface (Facies vesicalis) is in contact with the bladder, and has 

 inconstant relations with various parts of the intestine. The term fundus uteri 

 is applied to the anterior wide part from which the cornua diverge. 



The position of the body of the uterus is variable, especially in regard to its anterior part. 

 It is often pressed up against the rectum, and may be deflected to either side — most frequently 

 to the left — by the pelvic flexure of the colon or coils of the small colon. 



The cervix or neck of the uterus (Cervix uteri) is the constricted posterior 

 part which joins the vagina. Part of it (Portio vaginalis uteri) projects into the 

 cavity of the vagina; it is therefore not visible externally, but may be felt 

 through the vaginal wall. It is about two inches (5 cm.) in length, antl an inch 

 and a half (3.5 to 4 cm.) in tliamoter. 



Attachments. — The l)ody and cornua are attached to the abdominal and pelvic 

 walls by two extensive peritoneal folds, the broad ligaments (Ligamenta lata). 

 These extend on either sitle from the subhnnbar region and the lateral pelvic walls 

 to the dorsal border of the cornua and the lateral margins of the body of the uterus. 

 They contain the vessels and nerves of the uterus and ovaries, connective tissue, 

 and unstriixnl nuiscular fibers. The ureters are situated along their parietal 

 margins. The outer layer of each forms a fold, the round ligament of the uterus 

 (Ligamentum teres uteri), which blends with the ])arit'tal peritoneum over the 

 internal inguinal ring; its anterior extremity is situated above the extremity of 

 the cornu and is rounded and free. It contains nuiscular tissue, vessels, and 

 nerves, and is the homologue of the gubernaculum testis. The anterior part of 

 the neck is continuous with the vagina, and thus has a more fixed position than 

 the rest of the organ. 



The cavity of the uterus (C'avum uteri) is largely obliterated in the non- 

 pregnant state by the contraction of the wall and by folds of the mucous lining. 

 At the extremity of each cornu it conununicates Ijy a minute opening with the 

 Fallopian tube. The cavity of the neck is termed the cervical canal (Canalis 

 cervicis); it is closed ordiiuii'il}' by n\ucous folds and a plug of nuicus. It opens 

 into the vagina by the os uteri externum, and into \hv l)ody by thcos uteri internum. 



Structure. — The wall of the uterus consi.sts of three coats — an external serous, 

 a middle muscular, and an internal mucous. The serous coat (Perimetrium) is, 

 for the most part, closely adherent to the muscular coat. It is continuous with 

 the l)road ligaments. The muscular coat consists essentially of two layers, a thin 

 external stratum of longitudinal fib{>rs, and a thick laj'er of circular fibers. 

 Between these is a very vascular layer (Stratum vasculare) of connective tissue 

 with circular and oblique muscular fibers in it. The circular coat is very thick 

 in the neck, where it forms a sphincter half an inch or more (ca. 1.5 cm.) in 

 thickness. The mucous membrane rests directly on the muscular coat. It is 

 thick, and is covered l)y colunniar epitheliimi. It contains numerous long tubu- 

 lar uterine glands (Glandulse uterinse). It is brownish-red in color, except in the 

 neck, where it is pale. 



Vessels and Nerves. — The chief arteries are the uterine and the uterine 

 branch of the utero-ovarian, which have a flexuous course in the broad ligaments; 

 there is also a branch from the internal pudic artery. The veins form pam- 

 piniform plexuses and accompany the arteries. The lymphatics are numerous 

 and go to the internal iliac and lumbar glands. The nerves are derived from the 

 sympathetic through the uterine and pelvic plexuses. 



The foregoing statements refer to the non-gravid uterus. In the pregnant state it under- 

 goes important changes in size, position, and structure. The increase in size affects chiefly the 

 gravid cornu (except in the case of twins) and the body. The cornu attains a length of about 

 two and a half to three feet (ca. 80 to 90 cm.), and a corresponding diameter; in this process it 

 extends much beyond the ovary, and the broad ligament. The gravid uterus is entirely abdominal 

 in position, and extends along the ventral wall, chiefly to the left of the median plane. It weighs 

 about nine pounds (ca. 4 kg.), according to Ellenberger. The broad ligaments increase greatly 

 33 



