GASTEIC DILATATION. 361 



enlarged mesenteric or retroperitoneal glands, or even by 

 aneurysms of the abdominal aorta or cosliac axis. 



Very diverse estimates as to the normal capacity of the 

 stomach are current. It may perhaps be fixed as being from 

 thirty-five to forty ounces in the adult. In children up to six 

 months of age the gastric capacity may be approximately stated 

 to be an ounce more than the age of the child in months ; at 

 birth it is barely an ounce, at one month the capacity is two 

 ounces, and at six months it is seven ounces. At twelve months, 

 however, the capacity is but nine ounces, and at eighteen months 

 it is twelve ounces. 



Dilatation of the stomach is inferred from an increase in its 

 superficial area, as determined by physical examination. It is 

 important to remember that when the stomach is contracted a 

 part of the transverse colon may lie in front of it. Sometimes 

 the actual outline of the stomach can be seen ; at others it must 

 be determined by auscultatory percussion. Inflation is often 

 necessary, and the valvular mechanism of the cardia, coupled 

 with the obstruction at the pylorus, renders this easy of accom- 

 plishment by effervescing mixtures or by an air pump and 

 stomach tube. Since the cardiac end of the dilated stomach 

 accurately fits the left dome of the diaphragm, the fundus of 

 the distended stomach rises to the same level as this dome, and 

 lies a little above and internal to the position of the cardiac 

 impulse. The proximity of the stomach to the heart is held 

 accountable for the palpitation and dyspnoea sometimes produced 

 by gastric distension. The cardiac sounds may be echoed by 

 the air-containing stomach, and its encroachment on the base of 

 the lung may simulate pneumothorax in childhood. 



The greater curvature of the stomach emerges from beneath 

 the left costal margin at the level of the ninth costal cartilage 

 (corresponding to the position of the gall bladder on the 

 opposite side). The lower border of a normal stomach when 

 inflated should not extend lower than a line joining the tips of 

 the tenth costal cartilages, or two inches above the umbilicus. 

 (Fig. 49, p. 362.) 



