394 



DIGESTIVE SYSTEM OF THE OX 



behind the oesophageal groove and about four to five inches lower down. Undoubtedly food 

 or water swallowed with a moderate degree of force passes first into the rumen. Foreign bodies 

 (which are commonly swallowed by cattle) are, however, found in the reticulum. 



The cardiac orifice is opposite the seventh rib, a httle to the left of the median 

 plane and about four inches (ca. 10 cm.) below the spine; it is not funnel-shaped. 



The mucous membrane of the rumen is brown in color, except on the margins 

 of the pillars, where it is pale. It is for the most part thickly studded with large 

 papilliE, many of which are nearly half an inch (ca. 1 cm.) long. The edges of the 

 chief pillars and a large part of the wall of the middle of the dorsal sac are, however, 

 not papillated. The papillary arrangement is most marked in the blind sacs. 

 The papillae vary much in size and form; the largest are foliate, many are narrow 

 or filiform, and others are conical or club-shaped. The mucous membrane on the 

 inner wall of the atrium is finely wrinkled and non-papillated, while above and 



Fig. 289. — Thoracic and Anterior Abdominal Viscera of Ox, Deep Dissection. 

 Most of the rumen has been removed and the left wall of the reticulum cut away. A., Left pulmonary 

 artery; B., left bronchu.s; V. V. V., jjulmonary veins; b. b., bronchial lymph glands; L.g., posterior mediastinal 

 lymph-gland; D., termination of duodenum; F, rumino-reticular fold. 



externally it is papillated. The papillary arrangement also extends over the edge 

 of the rumino-reticular fold an inch or two (ca. 2 to 5 cm.). 



The oesophageal groove (Sulcus oesophageus) is a semicanal which begins at 

 the cardia and passes downward (ventrally) on the right wall of the reticulum to 

 end at the reticulo-omasal orifice. It is about six or seven inches (ca. 15 to 18 

 cm.) in length. Its axial direction is practically vertical, but it is twisted in a spiral 

 fashion; thus its thickened edges or lips project first backward, then to the left, 

 and finally forward. The twist involves chiefly the left lip, and the relative posi- 

 tions of the lips is reversed at the ventral end. 



The mucous membrane on the lips of the cpsoi^hageal groove is brown and 

 wrinkled, like that of the atrium; in the bottom of the groove it is pale, like that 

 of the oesophagus, marked by longitudinal folds, and i)rcsents jiointed horny liapillse 

 on the lower part. 



The reticulo-omasal orifice (Ostium reticulo-omasicum) is situated in the right 



