528 



EESPIKATOEY SYSTEM OF THE HORSE 



Trapezius 



Rhombuiileus 



Spinalis 



Miiltifiiliis 



CaiiihiQc of scapula 



- Longissimus dorsi 



Scrratus dorsalis 

 Lci'alor casta; 

 cl intercost. ext. 

 Longissim us cosiarum 

 Iidercostaliis 



Serratus ventroMs 



L'ltissinius dorsi 



Culiineus 



Triceps (c. lorigum) 



Pecloralis pfroj. 

 {p. humeralis) 



Tensor fascial 

 antibrachii 



Pecloralis superficialis 

 (p. transversa) 



Fig. 470. — Section of Thorax op Horse. 



The section is cut in an oblique direction corresponding with the spine of the scapula. It cuts the body of the 

 seventh thoracic vertebree and the seventh rib dorsally and the fourth rib and its cartilage ventrally. The pleural 

 and pericardiac cavities, represented by wide black lines, are exaggerated for the sake of clearness. 



L, L', lungs; 1, aorta; 2, cesophagus; 3, thoracic duct; 4, vena azygos; 5, 5', bronchi; 6, bifurcation of pulmonary' 

 artery; 7, 7', right and left atria; 8, right ventricle; 9, tricuspid valve; 10, origin of aorta; 11, right coronary artery; 

 12, left coronary arterj' (circumflex branch) and satellite vein; 13, internal thoracic vessels; 14, external thoracic 

 vessels; S, sternum; U, ulna. The following structures are shown, but not marked on account of lack of space: The 

 right vagus is on the oesophagus and ventral to the vena azygos. The phrenic nerves are on the upper part of the peri- 

 cardium on each side. The sympathetic trunks are on each side of the body of the vertebra. The number 10 is placed 

 on the ventricular septum. Bronchial lymph-glands are shown ventral to the oesophagus and the left bronchus. 



