DIGESTION. 177 



esophagus; over the remainder of the stomach they are thinly scat- 

 tered, but toward the pyloric orifice they are more numerous and 

 form a tolerably thick layer which becomes continuous with the 

 fibers of the small intestine. The circular__fibers form a complete 

 layer encircling the entire organ, with the exception, perhaps, of a 

 portion of the fundus. The fibers of this coat cross the longitudinal 

 fibers at right angles. At the junction of the fundus with the pyloric 

 antrum the circular fibers are arranged in a well-defined bundle 

 termed the sphincter antri pylorici. In the pyloric region the circular 

 fibers are more closely arranged, forming thick annular rings. At 

 the pyloric opening the circular fibers are again crowded together and 



FIG. 71. FIBERS SEEN WITH THE STOMACH EVERTED, i, i. Esophagus. 2. Circular 

 fibers at the esophageal opening. 3, 3. Circular fibers at the lesser curvature. 

 4, 4. Circular fibers at the pylorus. 5, 5, 6, 7, 8. Oblique fibers. 9, 10. Fibers 

 of this layer covering the greater pouch, n. Portion of the stomach 'from which 

 these fibers have been removed to show the subjacent circular fibers. (Sappey.) 



form a distinct muscle band, the sphincter pylori, which -projects 

 for some distance into the interior of the stomach. It has been stated 

 by Riidinger that the inner fibers of the longitudinal coat become con- 

 nected with this circular band and constitute a distinct muscle, the 

 dilatator pylori. The oblique fibers are most distinct over the cardiac 

 portion of the stomach, but extend from left to right as far as the 

 junction of the middle and last thirds of the stomach. They are 

 continuations of the circular fibers of the esophagus. 



The submucous coat consists of loose areolar tissue carrying 

 blood-vessels, nerves, and lymphatics. It serves to unite the muscle 



