THE THORACIC CAVITY AND PLEURA 



461 



THE THORACIC CAVITY AND PLEURA 

 The thoracic cavity is relatively small ; it is especially short dorsally, and is 

 diminished laterally In' the mode of attachment of the diaphragm to the ribs (vide 

 Myology). The endothoracic fascia is better developed than in the horse, and is 



Fjg. 366 —Cross-section of TnoRAx of Sheep, Passing Through Middi.f of Fifth Pair of Ribs, Posterior 



View. 

 ; 1' Lungs- 5, ^', bronchi; S, S', pulmonary arteries; 4, thoracic aorta; 5, oesophagus; 6, lymph gland; 

 7 vena hemiazygos; S, posterior vena cava; 5, large pulmonary vein; iO, left atriuxii. J i, vena hemiazygos; 

 /^, left ventricle; W, right ventricle; ^4, sternum; ;.5, internal thoracic vessels; iff, six' ti .loracic vertebra. 



distinctly elastic. The pleura is also thick, and there are no perforations of the 

 mediastinum. The pleural sacs are more unequal in extent than in the horse, and 

 the ventral part of the mediastinum is further to the left; in front of the pericar- 

 cUum it lies for the most part on the left wall of the chest. 



