20 



TOPOGRAPHICAL ANATOMY OF THE 



accouiniodation of the heart. The cardiac notch (incisura cardiaca) is 

 deeper in the left lung than it is in the right ; consequently more 

 of the heart is uncovered by lung on the left side of the chest than on 

 the right. 



The apex of the lung (apex pulmonis) is free, blunt, and laterally 

 flattened. 



The base (basis pulmonis), being applied to the diaphragm, possesses 

 a concave surface (facies diaphragmatica) which slopes in a caudal and 

 lateral direction. Except medially, the border circumscribing the base 

 is sharp and fits into the narrow space (sinus phrenicocostalis) between 

 the diaphragm and the ribs. 



A. pulmonalis 



Groove for costo-cervical 

 venous trunk. I 



Groove for deep j 

 cervical vein 



Bronchus. 



Groove for v. azygos. 



Dorsal border. 



Groove for aorta. 



Groove for oesophagus. 



Cardiac impression. 



Cardiac notch 



Vv. pulmonales 



Diaphragmatic surface. 



Line of reflection of pleura. 

 Intermediate lobe. 



Fk;. 8. — Medial aspect of the right lung. The arrow indicates the position of 

 the caudal vena cava. 



Dissection. — The constituents of the roots of the lungs should now 

 be isolated. In removing the pleura and the fatty connective tissue, 

 great care should be exercised not to injure the pulmonary plexus of 

 nerves. 



The various structures forming the root should be followed into the 

 interior of the lung in order that their manner of branching may be 

 observed. 



The root of the lung (Radix pulmonis). — The roots of the lungs 

 are placed about the junction of the dorsal and middle thirds of the 

 dorso-ventral diameter of the thoracic cavity, and opposite the fifth rib 

 and the fifth intercostal space. 



Each root contains the following structures : — (1) Several pulmonary 

 veins conveying the aerated blood from the lungs to the heart. 

 (2) Pulmonary artery distinguished from the veins by the greater 



