298 



DISSECTION OF THE ABDOMEN. 



Jntertuber- 

 cular plane. 



Vertical 



planes. 



Names of 



regions. 



Other sub- 

 divisions. 



Viscera seen 

 without 

 displace- 

 ment. 



General 

 division of 

 alimentary 

 tube; 



position of 

 several 

 parts ; 



and of 

 solid organs. 



the lower border of the body of the sternum. This plane, from its 

 traversing the pyloric end of the stomach, is called the transpyloric. 



The lower horizontal plane is half-way between the transpyloric 

 and the upper border of the symphysis pubis, and it fairly corre- 

 sponds to the plane between the tubercles on the outer lips of the 

 iliac crest (Cunningham), and is therefore called the intertubercular. 



The vertical planes are represented by (1) the middle line of the 

 body, and (2 and 3) by the right and left lateral lines. These 

 lateral lines are drawn vertically on each side through a point mid- 

 way between the middle line and the anterior superior iliac spine. 



The regions of the abdomen thus delimited are named respectively, 

 from above downwards, on either side of the middle line, the right 

 and left epigastric, umbilical, and liypogastric regions, and at the sides 

 of the body the right and left hypochondriac, lumbar, and iliac regions. 



In addition, the middle and lower part of the liypogastric space is 

 named pubic region, while the contiguous portions of the hypogastric 

 and iliac constitute the inguinal region. 



The various bony and other surface points already referred to on 

 the superficial examination of the abdomen (p. 260) are useful in vary- 

 ing degrees as guides to the subjacent parts, but the arch formed 

 by the costal cartilages (costal margin, tig. 108) is very variable in 

 its position, and cannot be relied on as a surface guide except near 

 the sternum. Moreover, the different costal cartilages often cannot 

 be located in fat persons. 



Superficial view. On first opening the abdomen the following 

 viscera appear (fig. 109, and fig. Ill, p. 303) : Above and to 

 the right is the liver, which is in great part concealed by the ribs. 

 Lower down, and more to the left, a piece of the stomach is visible ; 

 but this viscus lies mostly beneath the ribs and the liver. Descend- 

 ing from the stomach is a loose fold of peritoneum (the great 

 omentum), which may reach to the pelvis, and conceal the small 

 intestine, but in some bodies is raised into the left hypochondriac 

 region, and leaves the intestine uncovered. The caecum is usually 

 to be seen in the right iliac region ; and sometimes a part of the 

 pelvic colon (sigmoid flexure) comes to the surface in the corresponding 

 situation on the left side. 



Close behind the pubic sympli3 T sis is the apex of the bladder (bl), 

 with the urachus (ur) continued upwards from it ; and if the organ 

 is distended, it rises above the symphysis. 



The alimentary tube presents differences in form, and is divided 

 into stomach, small intestine, and large intestine ; and the two last 

 are further subdivided, as will afterwards appear. The several 

 viscera have the following general position : The small intestine 

 is much coiled, and occupies the greater part of the cavity ; while 

 the great intestine arches round it. Both are held in position by 

 portions of the serous lining. Above the arch of the great intestine 

 are situate the stomach, the liver, and the spleen ; behind is the 

 pancreas ; and below it is the convoluted small gut. Behind the 

 intestine, on each side, is the kidney with its excretory tube. 



