WALLS OF THE ABDOMEN. 539 



the cartilages. The right contains the right lobe of the 

 liver ; portion of the duodenum, and colon. The left con- 

 tains the spleen, the left extremity of the stomach, part of 

 the left extremity of the liver, and left end of the pancreas. 



The lumbar regions, upon each side of the umbilical, con- 

 tain the right and left kidneys, with the ascending and 

 descending portions of the colon. 



The iliac are on each side of the hypogastric ; the right 

 contains the termination of the ilium, and commencement 

 of the colon, or caput-coli the left has the termination 

 of the colon, called the sigmoid flexure. The lower portions 

 of the iliac regions receive the names also of inguinal or 

 spermatic. 



^ 



SECTION I. 



WALLS OF THE ABDOMEN. 



The anterior and lateral walls are composed chiefly of 

 muscles and fascia. 



Dissection. Make an incision from the symphysis pubis, 

 to the end of the second bone of the sternum. From this 

 latter point, carry a second incision obliquely downward 

 and outward towards the arm-pit, and onward to the spine. 

 A third incision, commencing on the second, about the 

 middle of the chest, and carried downward and inward 

 towards the spine of the pubis, will be in the direction of 

 the fibres of the superficial or external oblique muscle, at the 

 upper part of which line the dissection should commence. 



The muscles are five pair three broad, and two narrow. 

 The broad are the external oblique, internal oblique, and 

 transversalis ; the narrow are the rectus abdominis, and 

 pyramidalis. 



The external oblique muscle, (obliquus externus abdominis 

 descendens) so named from the direction of its fibres, is the 

 most superficial of all the abdominal muscles, and the 

 largest. It is thin and broad, and arises, by fleshy and 

 tendinous digitations, from the eight or nine inferior ribs, 

 at their lower edges and anterior surfaces, near the car- 



