

PEEITONEUM. 



1237 



: 



s somewhat complicated, and is fully described in connexion with the several 

 Ivic organs. A general account will suffice here. 



Having passed over the superior aperture all round, it enters the pelvis minor, 

 d covers its walls as low as the pelvic floor, across which it passes to the various 

 organs. Behind, it invests the pelvic colon completely, and forms a mesentery 

 (pelvic mesocolon) for it, as far down as the third sacral vertehra. There the colon 

 joins the rectum proper, and the complete investment of the bowel ceases. 



As the end of the pelvic colon is approached the two layers of its mesocolon 

 become shorter, and when the rectum is reached, they separate, leaving its posterior 

 surface uncovered, whilst the bowel is clothed in front and at the sides. Lower 

 down, the membrane leaves the sides, and finally, at a point which is usually about 

 3 inches (7'5 cm., see p. 1224) above the anus, it leaves the anterior surface of the 

 bowel, and in the male is carried on to the posterior part of the bladder (here covered 



Second sacral vertebra 



Sacro-iliac joint 



Rectum 



Pararectal fossa 



Ending of pelvic mesocolon 



Sacral nerves 



Ureter (cut) 

 Crescentic fold of 

 peritoneum (recto- 

 genital fold) 

 Seminal vesicle 

 beneath this 



external iliac 

 vein 



Sxternal iliac 

 artery 



Pararectal fossa 



Ureter (cut) 

 Hypogastric artery 

 Obturator nerve 

 Ureter 



epigastric artery 



Ureter 



Paravesical fossa / 

 Plica vesicalis transversa 



Rectus 



Iliacus 



/ 

 Pyramidalis 



. External iliac artery 

 Ductus deferens 

 Obliterated umbilical artery 

 \ Urinary bladder 

 Median umbilical ligament (urachus) 

 FIG. 965. THE PERITONEUM OP THE PELVIC CAVITY. 



ie pelvis of a thin male subject aged 60 was sawn across obliquely. Owing to the absence of fat the 

 various pelvic organs are visible through the peritoneum, though- not quite so distinctly as represented 

 here. The urinary bladder and rectum were both empty and contracted ; the paravesical and pararectal 

 fossae, as a result, are very well marked. 



the seminal vesicles and deferent ducts), forming the floor of the excavatio 

 ;to-vesicalis (recto-vesical pouch), between those organs. It then covers the 

 superior surface of the bladder, and passing off from its sides to the walls of 

 the pelvis, constitutes the so-called false ligaments of the bladder. From the 

 apex of the bladder it is carried on to the anterior abdominal wall by the middle 

 umbilical ligament, thus forming the plica pubovesicalis (O.T. the superior or 

 anterior false ligament of the bladder). 



In the female (Fig. 964), the peritoneum, on leaving the rectum, passes to the 

 posterior wall of the vagina, the superior portion of which it covers. From that it 

 is continued up over the posterior surface and fundus of the uterus, and down on 

 its anterior surface as far as the junction of the cervix and body (Fig. 964). Here 

 it passes from the uterus to the bladder, which it partly covers, as in the male, and 

 is then carried on to the anterior abdominal wall. Between the rectum behind, 

 and the uterus and vagina in front, is situated the excavatio rectouterina [cavum 

 Douglasi] (O.T. pouch of Douglas), the entrance of which is limited, on each side, 



