398 



DIGESTIVE SYSTEM OF THE OX 



The small intestine has an average length of about 130 feet (ca. 40 m.) and 

 a diameter of about two inches (ca. 5 to 6 cm.). 



The duodenum is about three or four feet (ca. 1 m.) in length. It passes for- 

 ward to the visceral surface of the liver; here it forms, ventral to the right kidney, an 

 S-shaped curve. Thence it runs backward almost to the external angle of the ilium, 

 where it turns on itself, passes forward alongside of the terminal part of the colon, 

 and joins the mesenteric part (jejunum) under the right kidney. It is attached to 

 the liver by the lesser omentum, to the abomasum by the great omentum, and to 



the terminal part of the colon. The bile duct 

 opens in the ventral part of the S-shaped curve, 

 about two feet (ca. 60 cm.) from the pylorus. 

 The pancreatic duct oi:)ons about a foot (ca. 30 

 cm.) further l^ack. 



The remaintler of the small intestine is ar- 

 ranged in numerous very close coils, in contact 

 chiefly with the right face of the ventral sac of 

 the rumen, forming a sort of festoon at the edge 

 of the mesentery. It is not subject to much 

 variation in position, but a few coils may find 

 their way behind the blind sacs of the rumen 

 to the left side. 



The orifices of the pancreatic duct and the 

 bile duct are on papillae, no diverticulum being 

 present. There are permanent transverse folds 

 of the mucous membrane (Plicae circulares). 

 Duodenal glands (of Brunner) occur in the first 

 fifteen feet or more (4 to 5 m.), intestinal glands 

 throughout. Peyer's patches are larger and 

 more distinct than in the horse, and vary 

 greatly in size and number; in adult cattle 

 there are eighteen to forty; in calves, twenty 

 to fifty-eight. They usually have the form of 

 narrow bands. Close to the ileo-caecal valve 

 there is always a patch, and in most cases 

 there is also a patch on the caecal side of 

 the valve. 



The large intestine is much smaller in 

 caliber than that of the horse, has no bands, 

 and is not sacculated. Most of it is situated 

 between the layer's of the common mesentery. 



The caecum is about 20 to 30 inches (ca. 50 

 to 60 cm.) long, 4 to 5 inches (ca. 10 to 12 cm.) 

 wide, and has a capacity of about 2^^ gallons 

 (ca. 9 to 10 liters). It begins opposite the 

 lower part of the eleventh rib, and extends 

 the right flank; its rounded blind end is free, 



i 



P 



n 



Fig. 293. — Peter's Patches of Small In- 

 TESTi.NE OF Ox (about J natural size). 



upward and backward against 

 and lies near or in the pelvic inlet 



The colon is about 35 feet (ca. 10 ni.) long; its diameter is at first about the 

 same as that of the caecum, but diminishes to about two inches (ca. 5 cm.). Its 

 capacity is al)out 6 to 8 gallons (ca. 25 to 30 liters). With the exception of its 

 first and terminal parts, it is arranged in double elliptical coils between the layers 

 of the mesentery; the adjacent parts are therefore alternately centripetal and 

 centrifugal (Gyri centripetales et centrifugales). The first part (Ansa proximalis) is 

 marked off from the caecum only by the ileo-caecal opening; it forms an S-shaped 



