37 o APPLIED ANATOMY. 



necessitate resection of the head of the metacarpal bone, which will materially weaken 

 the hand. The two palmar digital arteries will require ligation, and the tendons 

 should be sutured over the face of the bone or to their sheaths, closing them. 



THE ABDOMEN. 



The abdomen comprises that part of the body anterior to the spine and erector 

 spinae and quadratus lumborum muscles, and from the diaphragm above to the rim 

 of the pelvis below. The true pelvis is not included. The peritoneal cavity em- 

 braces the cavity of the abdomen and also that of the pelvis. An accurate knowledge 

 of the topographical anatomy of the abdomen with its various contained organs is 

 absolutely essential to both the physician and the surgeon for diagnostic purposes, 

 and especially to the latter in carrying out his operative procedures. The surface o: 

 the abdomen should be studied with reference to physical diagnosis ; its walls, 

 because herniae frequently protrude through them, and because they must be tra- 

 versed in obtaining access to the structures within; its contents, in order to properly 

 carry out necessary operative measures. 



SURFACE ANATOMY OF THE ABDOMEN. 



The rounded form of the abdomen is influenced by its bony support, by the 

 muscles and fascias attached to these bones, and by the organs within. In the upper 

 portion of the abdomen the tip of the ensiform cartilage can be felt it is opposite 

 the eleventh dorsal vertebra. Immediately above the ensiform cartilage is its junc- 

 tion with the second piece of the sternum, which is opposite the tenth dorsal verte- 

 bra, the sixth and seventh costal cartilages meet at this point, the seventh, eighth, 

 ninth, and tenth cartilages can be followed down to the lower border of the chest ; 

 just below this, one free rib, the eleventh, can be distinguished and sometimes in thin 

 people the twelfth; but the twelfth is often not palpable because it is buried beneath 

 the erector spinae muscles. The most certain way of identifying any particular rib 

 is to count from the sternal (Ludwig's) angle, opposite the second rib. 



Below, the crest of the ilium can be followed back to the posterior superior spine 

 of the ilium and in front to the anterior superior spine. The spines of the pubes can 

 be recognized, as well as the upper edge of the pubic bones. The depressions for 

 the linea alba, lineae semilunares, and lineae transversae are all more marked above the 

 umbilicus. The umbilicus lies on the disk between the third and fourth lumbar ver- 

 tebrae, about 2.5 cm. (i in.) above a line joining the highest points of the crests ol 

 the ilia. It is just below the midpoint between the symphysis and ensiform cartilage. 



Regions. For clinical purposes the abdomen has been divided into regions, so 

 that the location of tumors, signs, etc., can be readily indicated. The most conven-. 

 ient division is into nine regions by two transverse and two longitudinal lines. The 

 upper transverse line passes from the tip of the tenth rib which corresponds to the 

 lower end of the thorax on one side to that of the other. The lower transverse line 

 passes from the anterior superior spine of the ilium on one side to that of the oppo- 

 site ; it is on a level with the second sacral vertebra. The two longitudinal lines pass 

 directly up on each side from, the middle of Poupart's ligament. They strike the 

 cartilages of the eighth ribs, but at too indefinite a point to serve as a guide. 



The middle regions are the epigastric, the umbilical, and the hypogastric, or 

 pubic. The lateral regions are the right and left hypochondriac, the right and left 

 lumbar, and the right and left iliac. 



The abdomen is sometimes divided into four quadrants by a longitudinal median 

 line and a transverse line through the umbilicus. This mode of division is used 

 more by physicians than by surgeons. 



The lower transverse line is drawn by Quain and Cunningham from the top of 

 the crest of one ilium to that of the other, but as the umbilicus is often lower than 

 usual this line may pass above it. Anderson (Morris's "Anatomy") suggests 

 using the lineae semilunares instead of the usual longitudinal lines, but as yet this 

 modification has not been generally accepted. 



