QUESTIONS AND ANSWERS 81 



Describe the stomach. 



The stomach is a muscular sac, situated in the diaphragmatic 

 region between the oesophagus and the duodenum, in which the 

 principal acts of digestion take place. It has a capacity of 3 to 314 

 gallons and weighs from 3 to 4 pounds. It is elongated, often con- 

 stricted in its middle, and presents an anterior and a posterior face, 

 a great curvature below, to which the great omentum is attached, 

 a lesser curvature above, to which the oesophagus and gastrohepatic 

 ligament are attached. In the left extremity is an opening con- 

 tinuous with the oesophagus, and the right extremity conmiunicates 

 with the duodenum through the pyloric orifice. 



Externally, the stomach is covered with a serous coat, the peri- 

 toneum ; internally, it is lined with mucous membrane in which are 

 innumerable peptic and mucous glands. The middle coat is mus- 

 cular, the fibres of which run in various directions. 



Blood supply: gastric, splenic, pyloric, oesophageal, right and 

 left gastro-epiploic vessels. 



Nerves : pneumogastric and solar plexus. 



Give the relative capacity of the gastric cavities and intestines in (a) 

 horse, (b) the ox, (c) the sheep, (d) the pig, (e) the dog. 



(a) Stomach small, intestines large. 



(b) Stomach large, intestines small. 



(c) Stomach large, intestines small. 



(d) Stomach small, intestines large. 



(e) Stomach small, intestines large. 



Describe the rumen of the ox. 



The rumen is a large reservoir which occupies nearly three- 

 fourths of the abdominal cavity. It has a capacity of 45 to 50 

 gallons. Elongated from before, behind, it presents two surfaces, 

 superior and inferior, an anterior and posterior extremity and a 

 right and left border. 



By its superior surface, it is in contact with the intestines and 

 its opposite face lies on the inferior abdominal waU. Its left border, 

 supporting the spleen, extends to the highest part of the flank and 

 sublumbar region. The right border lies against the abomasum. 

 The anterior extremity lies close to the diaphragm and receives the 

 insertion of the oesophagus. The posterior extremity occupies the 

 entrance to the pelvic cavity. Interiorly, the rumen is divided by 

 two septa, muscular pillars, into a right and left sac. 



The rumen has three coats : outer serous, middle muscular and 

 inner mucous. The mucous coat has innumerable papillse similar 

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