THE ABDOMEN 889 



Uterus at Birth. — At birth the neck of the uterus is larger than 

 the body, and there is no fundus. At each superior angle it 

 tapers very much, and resembles somewhat a uterus bicomis. The 

 arbor vitae uterina extends all along the interior. 



Varieties. — These are as follows : (i) uterus bicomis ; (2) uterus unicornis ; 

 and {3) double uterus. 



For the structure and development of the uterus, see p. 896 

 et seq. 



Vagina. — ^This is a musculo-membranous passage which extends 

 from the cervix uteri to the vulva. It is from 3 to 3^ inches long, 

 being 3 inches along the anterior wall, and 3I inches along the 

 posterior. It is slightly curved, and its direction is downwards 

 and forwards. Its axis forms an obtuse angle with that of the 

 uterus (100° to 110°). In the erect posture it forms \Ndth the 

 horizontal an angle of about 60°. Superiorly it is closely connected 

 with the cervax uteri, the posterior wall rising higher than the 

 anterior. It is rather narrower at either end than at the centre, 

 the lower end being the narrowest part of the passage. The walls 

 are anterior and posterior, and they are in contact. In trans- 

 verse section the vagina appears as an H-shaped fissure at its 

 lower end, as a transverse fissure at the centre, and at its upper 

 end it presents a lumen which is almost circular. 



Relations — Anterior. — ^The base of the bladder, and the urethra. 

 Posterior. — From above downwards there are the pouch of Douglas 

 for a short distance, the rectum, with the intervention of the 

 recto-vaginal lamina of the visceral pelvic fascia, and the anal 

 canal, from which it is separated by the perineal body. The 

 posterior waU is covered by peritoneum over about its upper fourth. 

 Lateral. — ^The ureter at the upper end for a short distance, and 

 the levatores ani muscles. 



The vagina passes through the triangular ligament, and its 

 lower end has a bulbus vestibuh on either side, with the sphincter 

 vaginae surrounding the external orifice. \\Tien the finger is 

 passed into the posterior fornix, which is the recess between 

 the posterior lip of the os uteri externum and the posterior waU 

 of the vagina, the pouch of Douglas can be palpated, and a few 

 coils of the ilemn, or a prolapsed ovary, may be felt in it. The 

 base of the bladder may be palpated through the anterior fornix, 

 and the urethra through the anterior wall of the vagina lower 

 down. 



For the structure and development of the vagina, see Index. 



Bladder. — The base is directed backwards, and is related to the 

 front of the supravaginal portion of the cervix uteri and a portion 

 of the anterior wall of the vagina, the utero-vesical pouch of the 

 peritoneum intervening. The superior surface is in contact with 

 the anterior surface of the body of the uterus. The false ligaments, 

 formed by the peritoneum, are at least three in number, namely, 

 one superior and two lateral. The peritoneal folds on either side 



