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ANATOMY AND PHYSIOLOGY 



scrobiculus cordis, or pit of the stomach, is a slight depression at 

 the very point of the subcostal angle, caused by a weak spot in the 

 attachment of the abdominal muscles. If the abdomen is greatly 

 distended, the depression disappears. The linea alba is between 

 the two rectus muscles, and the semilunar lines (or line<z semi- 

 lunares) are at the sides of the recti. The transverse lines (linea 

 transversce) may be seen when the recti contract. 



The subcutaneous inguinal ring is just above the tubercle of the 

 pubic bone; the abdominal inguinal ring is a half inch above the 



Tip of ensiform cartilage 

 Costal border 



Upper horizontal plane 



Lower horizontal plane A, at 

 level of tubercles of iliac 

 crest 



Lower horizontal plane B, at 

 evel of anterior iliac spines 



Vertical plane A, from middle 

 of Pou part's ligament 



Vertical plane B, at outer 

 border of rectus (semi- 

 lunar line) 



Summit of symphysis pubis 



FIG. 235. DIAGRAM OF THE ABDOMINAL REGIONS. (Morris.) 



middle of the inguinal ligament. The conjoined tendon is behind 

 the subcutaneous ring. 



The abdominal muscles and skin are supplied by the lower 

 intercostal and first lumbar nerves. 



The regions of the abdomen are outlined in the following 

 manner: Imagine a horizontal plane passing through the ab- 

 domen at the level of the tenth costal cartilage, and another at the 

 level of the anterior superior spine of the ilium. These would 

 divide it into three portions upper, middle, and lower. Then 

 imagine two vertical planes passing through the middle point of 

 the inguinal ligament on either side, and dividing each of these 

 three portions into three regions, making nine in all. 



