790 
ANATOMY AND PATHOLOGY 
Figure 26. — The azygos system of veins. In this example 
there are good connections between the various parts 
of the hemiazygos system, annd several connections 
to the azygos (man) vein. 
Reproduced by permission from: W. Henry HoUinshead, TEXT- 
BOOK OP ANATOMY (ed. 2). Copyright (1967). Hoeber Medical 
Division — Harper & Row., New York. 
tomoses on the abomasum with the right gastric 
artery, a branch of the common hepatic artery, 
whereas the left gastroepiploic artery anas- 
tomoses along the greater curvature with the 
right gastroepiploic artery, a branch of the 
gastroduodenal artery, likewise from the com- 
mon hepatic artery (Figure 34). The splenic 
artery in the ruminant animal is smaller than 
that in the monogastric animal. It arises from 
the celiac artery by a common trunk with the 
right ruminal artery (Figure 36), and an ac- 
cessory artery to the spleen often originates 
from the left ruminal artery (Figure 37). The 
reticular artery (Figures 37 and 38) is the 
largest branch of the left ruminal artery before 
the latter dips into the left longitudinal groove. 
The reticular artery supplies the distal part of 
the esophagus, the area of the cardia, and the 
atrium ventriculi, and it sends grossly visible 
arterial twigs as vasa nervorum through the 
esophageal hiatus to the dorsal and ventral 
vagal trunks. There is the possibility of infarc- 
tion of visceral structures supplied by the de- 
scending portion of the reticular artery should 
the artery be obstructed by ligation in surgical 
procedures or by thrombosis. The gastric 
(esophageal) groove receives many arterial 
twigs from the left gastroepiploic branch of 
the left gastric artery. The ruminant stomach 
receives parasympathetic innervation by the 
dorsal and ventral vagal trunks (Figure 39). 
The ventral vagus nerve innervates the dia- 
phragmatic surface of the reticulum, the area 
of the atrium ventriculi liver and gall bladder, 
and iibers (the long pyloric nerve) followed 
the right gastric artery to the lesser curvature 
of the true stomach (abomasum). The dorsal 
vagus nerve courses to the visceral surface of 
the reticulum and sends branches along the 
right ruminal and left gastric arteries to the 
dorsal and ventral sacs of the rumen and both 
curvatures of the abomasum. The dorsal vagus 
also contributes to the celiac and cranial mesen- 
teric plexuses. 
The sympathetic innervation of the ruminant 
stomach is derived from the celiac, and cranial 
mesenteric plexuses and branches from the 
plexuses course to the stomach with arteries 
originating from the celiac trunk. 
In surgical procedures involving removal of 
the rumen and reticulum, the major vessels 
which must be identified and ligated are the 
right and left ruminal arteries, while blood 
vessels which must be preserved in order to 
avoid infarction of the true stomach are the 
common hepatic, left gastric and splenic vessels. 
