418 



DIGESTIVE SYSTEM OF THE HORSE 



Saccus cwcus 

 (left extremity) 



(Esophageal region 



Oesophagus 



Mar go 

 plicatus 



Fundus 

 gland 

 region 



Diverticulum duodeni 



Pyloric gland region 



Fig. 357. — Frontal Section of Stom.^ch and First Part of Duodenum of Horse. 

 C, Cardiac orifice. Photograph of specimen fixed in situ. 



ti.ssue which connects the muscular and mucous coats; in it the vessels and nerves 

 ramify before entering the mucosa. The mucous coat (Tunica mucosa) is clearly 



divided into two parts. That which 

 lines the greater part of the left sac re- 

 sembles the oesophageal mucous mem- 

 brane, and is termed the oesophageal 

 part (Pars cesophagea). It is white in 

 color, destitute of glands, and covered 

 with a thick, squamous, stratified epi- 

 thelium. At the cardiac orifice it pre- 

 sents numerous folds which occlude the 

 opening.^ It terminates abruptly, form- 

 ing an irregular, sinuous, raised edge, 

 termed the margo plicatus (or cuticular 

 ridge). Below and to the right of this 

 line the mucous membrane has a totally 

 different character, being soft and vel- 

 vety to the touch, and covered by a mu- 

 coid secretion. It contains the gastric 

 glands (Glandulse gastricse), and is there- 

 fore termed the glandular part (Pars glandularis). It is subdivided into three zones 

 according to the types of glands which it contains, but no distinct lines of demar- 



'■ Thi.s occlusion is usually so complete that distention of the stomach by air or fluid forced 

 in through the pylorus may be carried far enough to rupture the stomach without ligating the 

 oesophagus. 



Fig, 



358. — Diagram of Zones of Mucous Membrane 

 OF Stomach of Horse. 



