528 RESPIRATORY SYSTEM OF THE HORSE 
Trapezius 
— Rhomboideus 
— Spinalis 
’ A, Multifidus 
Cartilage of scapula 
3 Longissimus dorst 
Serratus dorsalis 
Levator coste 
et intercost. ext. 
Longissimus costarum 
Intercostales 
Serratus ventralis 
Latissimus dorst 
Cutlaneus 
Triceps (c. longum) 
Pectoralis prof. 
(p. humeralis) 
Tensor fascie 
antibrachtt 
Pectoralis superficialis 
(p. transversa) 
Fie, 470,—Serction or THORAX oF Horse. 
The section is cut in an oblique direction corresponding with the spine of the scapula. It cuts the body of the 
seventh thoracic vertebre 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, esophagus; 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 artery (circumflex branch) and satellite vein; 13, internal thoracic vessels; 14, external thoracie 
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 cesophagus 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 cesophagus and the left bronchus. 
