THE LUNGS 



463 



cardiac, and diaphragmatic. The right lung has four or five lobes; the apical 

 lobe is much larger than that of the left lung, and occupies the space ni tront o 

 the pericardium, pushing the mediastinum against the left wall;; the mediastmal 

 lobe resembles that of the horse, while the cardiac lobe is often divided by a fissure 

 into two parts. The apical lobe of the right lung receives a special bronchus from 

 the trachea opposite the third rib. The right lung is adherent to the trachea from 

 the second rib backward. 



Apical lobe 



Cardiac lobe 



Mediastinal lobe 



Dia-phragmatic lobe 



I 

 PosteriiT iiu,linstirud lymph gland 



PiQ 369.— LrxGS and Heart of Sheep, Ventral View. 

 Specimen hardened in situ. Space between heart and lungs was occupied by pericardium and fat. 



The interlobar fissures begin at the ventral mar-in of the lung and pass toward the root 

 Those of the letunfle opposite to the fourth and sixth ribs. The diaphragmatic lobe is the 

 largest and has the form of i tiiree-sided pyramid with its base ^ef ng on the diaphiag^. The 

 cardiac lobe is prismatic and forms the posterior margin of the cardiac notch ^s long axis corre 

 snonds to the fifth rib The apical lobe of the left lung is small and pointed, its ^entia maigin 

 Sron the pulmonary artery Ll the anterior aorta; below this ^he-pace m -nt o^ h^ 

 is occupied by the apical lol)e of the right lung. The cardiac lobe of the "g^t mig is much largCT 

 than that of the left lung, and covers the right face of the pericardium, so that the lattei has no 

 contact wdth the lateral wall of the thorax. 



The lobulation is very distinct on account of the extremely large amount of 

 interlobular tissue. 



1 It is therefore often termed the precardiac lobe. 



