THE INTESTINE 



139 



wise) which are continued from the similar layer of the esophagus, 

 and pass on to those of the intestine. 



The serous coat (or tunic) is a portion of the great serous mem- 

 brane of the abdomen, called the peritoneum (page 367). The 

 two surfaces of the stomach are covered by different layers of per- 

 itoneum which will be described elsewhere (Fig. in and p. 148). 



The gastric glands are embedded 

 in the mucosa. They are tubular in 

 form, microscopic in size, and very 

 numerous (their number is estimated 

 at 5,000,000). They differ markedly 

 in the two portions of the stomach. 

 The cardiac glands secrete the diges- 

 tive ferments, pepsin and rennin, 

 while the pyloric glands secrete mucus 

 also (Fig. 105). 



The reaction of the gastric juice is 

 acid (owing to hydrochloric acid). 

 This acid is a natural but not a 

 powerful antiseptic. 



The position of the stomach is 

 oblique, the pyloric end being on a 

 lower level than the cardiac. It is also the movable end. 



The location of the stomach is mostly in the epigastric region 

 (Fig. 235). It is below the portion of the diaphragm which 

 supports the heart; behind it are the largest artery and vein in the 

 body the aorta and the inferior vena cava. The pyloric end ex- 

 tends under the liver in the right hypochondrium, while the cardiac 

 end is in contact with the spleen in the left hypochondrium. 



Clinical notes. When the stomach is empty it tends to a vertical position 

 when filled, it swings upward and forward to become again oblique. If 

 much distended, as with gas, it embarrasses the action of the heart by pressure. 



The infant's stomach is nearly or quite vertical and easily overflows; its 

 capacity at birth is one ounce, reaching two ounces at about the end of a 

 fortnight and eight ounces at ten or eleven months. 



THE INTESTINE 



The intestine or bowel begins at the pyloric orifice of the 

 stomach and continues to the end of the alimentary tract. It is 

 from twenty-five to thirty feet in length (Fig. 106). 



FIG. 105. SECTION OF PYLORIC 

 GLANDS FROM HUMAN STOMACH. 

 a. Mouth of gland leading 

 into long, wide duct (&), into 

 which open the terminal divi- 

 sions, c. Connective tissue of 

 the mucosa. (After Pier sol.) 



