14 



ABDOMEN. 



reflection of the peritoneum from the anterior 

 abdominal wall upon the superior fundus and 

 posterior surface of the bladder : when that 

 viscus is empty and contracted, this fold dis- 

 appears totally ; it is more apparent when the 

 bladder is partially filled, and is still more 

 distinct in the foetus in consequence of the 

 greater size of the urachus at that period. 

 Just above the pubis the peritoneum is con- 

 nected to the abdominal wall by a very lax 

 cellular tissue; and accordingly when the blad- 

 der is much distended, the peritoneum is 

 pushed upwards, and stripped off the abdo- 

 minal wall to an extent proportioned to the 

 degree of distension of the bladder, so that its 

 anterior surface is then in immediate contact 

 with the abdominal wall, and may be opened 

 with impunity so far as the peritoneum is con- 

 cerned. 



The lateral walls of the abdomen are like- 

 wise completely lined by peritoneum, which 

 extends backwards as far as the junction of 

 these walls with the posterior, where it is re- 

 flected from them so as to involve the ascending 

 colon on the right side and the descending on 

 the left, and here it forms on each side the 

 folds respectively termed right and left meso- 

 colon. From the right lateral wall the peri- 

 toneum is continued upwards upon the dia- 

 phragm, and contributes to form the right 

 lateral ligament of the liver ; on the left side 

 it is continued in a similar manner on the 

 diaphragm, and in passing from the spleen to 

 that muscle forms the fold called splenico- 

 phrenic. 



The concave surface of the diaphragm is in 

 greatest part lined by peritoneum : the an- 

 terior half of the muscle is uninterruptedly 

 covered by peritoneum, which adheres very 

 closely to the central tendon, but is much more 

 easily separated from the muscular portion. 

 On the right side and in the middle, in front of 

 the cesophageal opening, the peritoneum is re- 

 flected from the diaphragm to the liver, forming 

 the right lateral, coronary, and left lateral liga- 

 ments of that organ. The posterior half of 

 this surface is likewise covered by peritoneum, 

 that membrane being deficient for a little way 

 behind the opening for the vena cava and 

 behind and on each side of the cesophageal 

 and aortic openings : the crura of the diaphragm 

 are covered chiefly on the outer side. 



The peritoneum comes into immediate con- 

 tact with the posterior abdominal wall only in 

 a very small portion of its extent : in tracing it 

 on the right side we find it covering the right 

 colon, then passing inwards over the kidney 

 and suprarenal capsule, the duodenum and vena 

 cava, to the eras of the diaphragm above, and 

 in the middle and below, where it also covers 

 the vena cava, and the renal vessels, to form 

 the right or superior lamina of the mesentery. 

 On the left side it covers in a similar manner 

 the left colon, the left kidney and capsule, and 

 that portion of small intestine which projects 

 just to the left of the superior mesenteric artery, 

 which may be regarded as the commencement 

 of the jejunum ; below this it manifests its 



continuity with the layer of the opposite side 

 by forming the left or inferior lamina of the 

 mesentery. This lamina commences at the 

 left side of the body of the second lumbar 

 vertebra; as it descends, it gradually crosses 

 more in front of the aorta, so as to terminate 

 at the right sacro-iliac symphysis ; the right 

 lamina is situated quite on the right side of the 

 spine. 



In the iliac fossae the peritoneum is in con- 

 nexion with the fascia iliaca, except where it is 

 separated by the coecum on the right side 

 (on which side it sometimes forms a fold termed 

 mesoccecum,} and by the sigmoid flexure on 

 the left. Internal to these portions of intestine 

 on each side, the peritoneum covers the ex- 

 ternal iliac artery and vein, from which it is 

 separated by a very loose and sometimes adi- 

 pose cellular tissue, and by a process of the 

 iliac fascia, to which allusion has already been 

 made. 



From the preceding description of the con- 

 nection of the peritoneum with the parietes 

 of the abdomen, it will appear how few are 

 the situations at which the surgeon could cut 

 through any portion of these walls without 

 risk of wounding the serous membrane. Im- 

 mediately above the pubis this may be done 

 in consequence of the abundance of cellular 

 membrane there which separates the serous 

 membrane from the wall ; but in the con- 

 tracted state of the bladder the operator must 

 proceed with the greatest caution : in the dis- 

 tended state of that viscus, however, the wall 

 of the abdomen is deprived of its lining to an 

 extent proportionate to the height to which the 

 bladder ascends behind the recti muscles; and 

 accordingly it is under such circumstances 

 that the paracentesis vesicae supra pubem, and 

 the high operation for the stone may be per- 

 formed with impunity to the serous membrane. 

 At the posterior wall an instrument may be 

 passed into any part of the posterior surface 

 of the kidney without injury to the peritoneum ; 

 the pelvis of the kidney, or any part of the 

 abdominal course of the ureter, may be opened 

 too, or the vena cava ; and by cutting into the 

 bodies of the vertebrae, and the muscular por- 

 tion of the posterior wall in the dead body, 

 a view of all the parts which lie upon that wall 

 may be obtained without at all injuring the 

 peritoneum.* 



Further details respecting the anatomy of 

 the peritoneum will be found in the article 

 under that head. 



Vessels and nerves of the abdominal walls. 

 a. The arteries. The most important arterial 

 ramifications are found in the anterior wall. 

 In the superficial fascia we find the superficial 

 epigastric artery or tegumentary artery, which 

 exists as a trunk in the iliac regions. This 

 artery, arising from the femoral, pierces the 

 fascia lata, and passes over Poupart's ligament 

 upwards and inwards, crossing the anterior 



* The reader may examine with advantage, Lud- 

 wig, Icones cavitatum thoracis et abdominis a tergo 

 apertarum. Leipzig, 1789. 



