THE ABDOMEN 



83: 



by defining the limits of the pelvic colon and rectum, and the 

 different parts of the bladder. The pelvic colon extends from the 

 inner border of the left psoas magnus, just anterior to the left 

 sacro-iliac articulation, to the level of the third sacral vertebra. 

 The rectum extends from the third sacral vertebra to a point 

 i^ inches in front of and below the tip of the coccjoc, where it 

 pierces the pelvic diaphragm to terminate in the anal canal, which 

 is the part of the large gut surrounded by the sphincter muscles. 

 The bladder, when empty, or only moderately distended, presents 

 the following parts : (i) an apex, which is directed forwards, and 

 lies behind the upper part of the symphysis pubis, where it has 

 connected with it the fibrous cord representing the urachus ; (2) a 



Pelvic Colon 



Line of Peritoneal Reflection 

 Ureter 



Vas Deferens 



Vesicula Seminalis 

 Bladder 

 / Urachus 



'j/i—il ^Symphy^ Pubis 



-^-! — U-,— Triangular Ligament 

 " "^ of Urethra 



^^~. Corpus Cavemosum 

 ^ Corpus Spongiosum 

 \ Bulb and Bulbo-cavemosus 

 '\ Colles' Fascia 

 ^^^^^^ . Perineal Pouch 



Levator Ani (cut) / ^7 \ ^ Membranous Urethra 



, • Cowper s Gland 



Anus ProsUte Gland and Capsule 



Fig. 362. — The Viscera of the Male Pelvis (Lateral View). 



base or fundus, directed backwards and downwards towards the 

 rectum, from which it is separated by the vesiculae seminales and 

 vasa deferentia ; (3) a body, which has a superior surface, an inferior 

 surface, and three borders, two being lateral and one posterior ; 

 and (4) a neck. 



The jDeritoneum, having descended from the posterior waU of the 

 abdomen over the common iliac vessels, enters the back part of 

 the pelvic cavity, where it invests the pelvic colon, forming behind 

 it an expanded, wavy mesentery, called the pelvic meso-colon, 

 which attaches it to the front of the sacrum as low as the third 

 sacral vertebra. The peritoneum is then prolonged upon the 

 rectum, the upper third of which it covers anteriorly and laterally, 

 but not posteriorly, the middle third being covered by it only 

 anteriorly, whilst the lower third is destitute of peritoneal covering. 



