SURGICAL ANATOMY OF THE IXTESTIXAL CASAL. 1045 



Surface Form. The coils of the small intestine occupy the front of the abdomen below the 

 transverse enlon. and are covered more or less completely by the great omentum. For the most 

 part the coil.- of the jejunum occupy the left side of the abdominal cavity i. e. the left lumbar 

 and inguinal regions and the left half of the umbilical region whilst the coils of the ileum are 

 situated to the right, in the right lumbar and inguinal regions, in the right half of the umbilical 

 region, ami also the hypogastric. The caecum is situated in the right inguinal region. Its posi- 

 tion varies slightly, but the mid-point of a line drawn from the anterior superior spinous process 

 of the ilium to the symphysis pubis will alxnt mark the .iddle of its lower border. It is com- 

 paratively superficial From it the ascending colon passes upward through the right lumbar 

 and hypochondriac regions, and becomes more deeply situated as it ascends to the hepatic flexure, 

 which is deeply placed under cover of the liver. The transverse coion crosses the belly trans- 

 versely on the confines of the umbilical and epigastric regions, its lower border being on a level 

 slightly above the umbilicus, its upper border just below the greater curvature of the stomach. 

 The splenic flexure of the colon is situated behind the stomach in the left hypochondrium. and 

 is on a higher level than the hepatic flexure. The descending colon is deeply seated, passing 

 down through the left hypochondriac and lumbar regions to the sigmoid flexure, which is situ- 

 ated in the left inguinal regions, and which can be felt in thin persons, with relaxed abdominal 

 walls, rolling under the fingers when empty, and when distended forming a distinct tumor. 



Surgical Anatomy. The small intestines are much exposed to injury, but, in consequence 

 of their elasticity and the ease with which one fold glides over another, they are not so frequently 

 ruptured as would otherwise be the case. Any part of the small intestine may be ruptured, but 

 probably the most common situation is the transverse duodenum, on account of its being more 

 fixed than other portions of the bowel, and because it is situated in front of the bodies of the 

 vertebrse. so that if this portion of the abdomen is struck by a sharp blow, as from the kick of 

 a horse, it is unable to glide out of the way. but is compressed against the bone and so lacerated. 

 Woundfl of the intestine sometimes occur. If the wound is a srnaH puncture, under, it is said, 

 three lines in length, no extravasation of the contents of the bowel takes place. The mucous 

 membrane becomes everted and plugs the little opening. The bowels, therefore, may be safely 

 punctured with a fine capillary trocar, in cases of excessive distension of the intestine with gas, 

 without fear of extravasation. A longitudinal wound gapes more than a transverse, owing to 

 the greater amount of circular muscular fibres. The small intestine, and most frequently the 

 ileum. may become strangulated by internal bands, or through apertures, normal or abnormal. 

 The bands may be formed in several different ways : they may be old peritoneal adhesions from 

 previous attacks of peritonitis ; or an adherent omentum from the same cause ; or the band 

 may be formed by Meckel's diverticulum, which has contracted adhesions at its distal extremity ; 

 or the band may be the result of the abnormal attachment of some normal structure, as the 

 adhesion of two appendices epiploicae, or an adherent vermiform appendix or Fallopian tube. 

 Intussusception or imagination of the small intestine may take place in any part of the jejunum 

 and ileum. but the most frequent situation is at the ileo-caecal valve, the valve forming the apex 

 of the entering tube. This form may attain great size, and it is not uncommon in these cases to 

 fin 1 the valve projecting from the anus. Stricture, the impaction of foreign bodies, and twist- 

 ing of the gut (vuh-tilug) may lead to intestinal obstruction. 



Foreign bodies and small hardened masses of faecal matter are very liable to become lodged 

 in the vermiform appendix. Here they set up inflammation, often cause perforation of the 

 appendix and formation of abscess in the loose connective tissue around. This may require 

 operative interference, and in some cases of recurrent attacks of appendicitis this little divertic- 

 ulum of the bowel has been removed. In external hernia the ileum is the portion of bowel 

 most frequently herniated. When a part of the large intestine is involved, it is usually the 

 ca?:-um. and this may occur even on the left side. In some few cases the vermiform appendix 

 has been the part implicated in cases of strangulated hernia, and has given rise to serious symp- 

 toms of obstruction. Occasionally ulceration of the duodenal glands may occur in cases of burns, 

 but is not a very common complication. The ulcer may perforate one of the large duodenal 

 vessels, and may cause death from haemorrhage, or it may perforate the coats of the intestine 

 and produce fatal acute peritonitis. The diameter of the large intestine gradually diminishes 

 from the caecum, which has the greatest diameter of any part of the bowel, to the point of 

 junction of the sigmoid flexure with the rectum, at or a little below which point stricture most 

 commonly occurs and diminishes in frequency as one proceeds upward to me caecum. When 

 distended by some obstruction low down, the outline of the large intestine can be defined 

 throughout nearly the whole of its course all, in fact, except the hepatic and splenic flexures, 

 which are more deeply placed : the distension is most obvious in the two flanks and on the front 

 of the abdomen just above the umbilicus. The caecum, however, is that portion of the bowel 

 which is. of all. most distended. It sometimes assumes enormous dimensions, and has been 

 known to be perforated from the pressure, causing fatal peritonitis. The hepatic flexure and 

 the right extremity of the transverse colon is in close relationship with the liver, and abscess of 

 this vis':-us sometimes bursts into the gut in this situation. The gall-bladder may become adherent 

 to the colon, and gall-stones may find their way through into the gut, where they may become 

 impacted or may be discharged per anum. The mobility of the sigmoid flexure renders it more 

 liable to become the seat of a vol vulus or twist than any other part of the intestine. It gener- 

 ally occurs in patients who have been the subjects of habitual constipation, and in whom, there- 

 fore, the meso-sigmoid flexure is elongated. The gut at this part being loaded with faeces, from 

 its weight falls over the gut below, and so gives rise to the twist. 



