94 



ANATOMY AND PHYSIOLOGY 



THE ABDOMINAL WALL 



The abdominal wall has no bones except the lumbar vertebrae, 

 being mostly muscular and aponeurotic. Each lateral half is 

 composed of one vertical muscle in front, next to the median line; 

 another in the back, next to the spinal column; and three well- 

 developed layers having fibers of different directions, at the sides. 



Rectus abdominis (Fig. 80). This is the vertical muscle in 

 front. Origin. The body of the pubes. Insertion. The ensi- 



FIG. 79. ANTERIOR SURFACE OF THE ABDOMINAL WALL. 

 !> 2, 3, 7, Pectoralis major; 4, external oblique; 5, serratus anterior; 6, latissimus 

 dorsi; 8, xiphoid appendix; 9, 9, 15, aponeurosis of ext. oblique; 10, 14, linea alba; 1 1, 

 umbilicus; 12, transverse lines of aponeurosis; 13, 13, subcutaneous abdominal ring; 

 16, 17, 18, 19, refer to muscles of neck; 20, deltoid. (Sappey.) Lower border of 

 aponeurosis is inguinal ligament. 



form appendix and the cartilages of the fifth, sixth, and seventh 

 ribs. It is therefore narrow below and broad above, and its outer 



