1372 CLINICAL AND TOPOGRAPHICAL ANATOMY 



of the internal mammary, the deep circumflex iliacs, the last two intercostals, and 

 the abdominal branches of the lumbar arteries. 



Of these, the inferior epigastric is the most important; its course will be marked out by a 

 line drawn from a point just medial to the centre of the inguinal ligament, upward and medially 

 to the medial side of the abdominal ring, and thence to a point about midway between the pubes 

 and umbilicus, forming the lateral boundary of Hesse Ibach's triangle (fig. 1121). Here the 

 vessel, which at first lies between the peritoneum and fascia transversalis, perforates the latter 

 and, passing over the semicircular line (fold of Douglas) enters the sheath of the rectus. It then 

 runs upward, closely applied to the back of that muscle, and, a little above the level of the 

 umbilicus, divides into branches which anastomose with the epigastric branch of the internal 

 mammarj'. 



One superficial vein in the abdominal wall needs especial mention, the thoraco-epigastric, 

 joining the veins of the chest, e. g., the long thoracic above with, the superficial epigastric 

 below. Its valves directing the blood downward below and upward above (Stiles) may be 

 rendered incompetent when this vessel is enlarged, as in interference with the portal vein, with 

 which it communicates by a vein in the round ligament, or in blocking of the inferior vena cava. 



Lymphatics. — It is sufficiently correct to say here that those above the umbilical line go 

 to the axillary, and those below that line to the inguinal nodes. 



Nerves. — The lower seven intercostals and the ilio-hypogastric and ilio- 

 inguinal supplj' the abdominal wall. The sixth and seventh intercostals supply 

 the skin over the upper epigastrium; the eighth, the area of the middle linea 

 transversa; the tenth, that of the umbilicus ; the last thoracic, ilio-inguinal and ilio- 

 hypogastric, the region above Poupart's ligament, and that of the pubes. The 

 ilio-hypogastric supplies the skin over the subcutaneous inguinal (external 

 abdominal) ring; the ilio-inguinal that over the cord and scrotum. The last 

 thoracic and ilio-hypogastric cross the iliac crest to supply the skin of the buttock. 



The diaphragm. — The upper hmit of the diaphragm rises to the following 

 levels in full expiration : Its central tendon to about the lower end of the body of 

 the sternum, or the seventh chondro-sternal joint; the right half to the fifth rib, 

 or about 1 cm. (| in.) below the nipple; the left half not rising quite so high, i. e., 

 to the fifth space, or 2.5 cm. (1 in.) below the nipple. 



Topographical relations of abdominal viscera. — These will include the 

 peritoneum, liver and bile passages, stomach, spleen, pancreas, intestines, 

 kidneys and ureters, and large abdominal vessels. 



The peritoneal spaces. — The peritoneum presents certain potential spaces, 

 determined by its various reflections from the parietes and abdominal viscera. 

 In these spaces collections of fluid such as abscesses or extravasations from hollow 

 viscera or blood vessels may collect and become shut off by adhesions or overflow 

 in various directions into neighbouring spaces. The transverse mesocolon and 

 great omentum together form a shelf transversely placed, which divides the greater 

 sac into two main divisions — supra-omental and infra-omental. 



The supra-omental region, in which the various forms of subphrenic abscess are found, con- 

 tains the following fo.ssa^ (Barnard).* (1) Right subphrenic, between the right lobe of the liver 

 and right cupola of the diaphragm, boimded toward the median line by the falciform ligament, 

 and behind by the coronary ligament. It communicates below with (2) the siihhepalic fossa 

 or right renal pouch (Morison), which is bounded above by the visceral siu-face of the liver, and 

 below by the mesocolic shelf and right kidney. It extends from the right lateral abdominal 

 wall, its most capacious part, across the median line under the left lobe of the liver, and on its 

 posterior aspect lie the upper pole of the right kidney, epiploic foramen, and anterior surface of 

 small omentum. (3) The left subphrenic, also known as the anterior perigastric fossa, lies 

 between the left dome of the diaphragm above, and the left lobe of liver, stomach, spleen and 

 omentum below. It is bounded on the right by the falciform ligament which lies somewhat to 

 the right of the median line. (4) The omental bursa may be regarded as a diverticulum from 

 the Hubhei)atic fos.sa with which it communicates by the epiploic foramen. Abscesses in this 

 .sac are rare, but occasionally laceration of the pancreas which is closely related to it behind 

 gives ri.sc to a collection of pancreatic juice and blood in the lesser sac, known as a pancreatic 

 psf'iido-cy.st (.Jordan Lloyd). 



The infra-omental region is subdivided in its abdominal part into (1) right and (2) left 

 compartments by the attachment of the root of the mesentery to the spine, descending from the 

 duorloiio-jc'junal flexure downward into the right, iliac fo.ssa. These fos.sa> communicate with the 

 supra-omontal regions in the neighbourhocjtl of the hepatic and splenic flexures of the colon 

 respectively, and l^elow with (3) the pelvis. The deepest level of the peritoneum lining the pelvis 

 fon.stitutes in the male the recto-vesical, and in the female the recto-vaginal fo.ssa (pouch of 

 Douglas). 



It should be noted that with a patient in the supine position, owing to the contour of the 

 p.soas muscles and the anterior convexity of the lumbar spine, any fluid above the pelvic brim 

 will tend to gravitate into the subplininic spaces across the flexures of the colon which lie far 

 back in the loin.s. This is unde.sirahle in view of the great absorbing power of the subphrenic 

 lymphatics, and may be obviated by propping the patient in a half-sitting position. 



♦Barnard, H. L., Brit. Med. Journal, Feb. 15, 1908. 



