SURFACE MARKINGS 211 



Mid-sternal indicated by a furrow between the origins of the 

 pectoralis major muscles. 



Mid-clavicular a line dropped from the mid-point of the 

 clavicle ; should be continuous with the vertical Poupart line, 

 .and passing through the tip of the ninth costal cartilage. 



Parasternal a line drawn midway between the side of the 

 sternum and the mid-clavicular line, and passes through the tip 

 of the eighth costal cartilage. 



Mammary region between two transverse lines drawn at the 

 levels of the third and sixth chondro-sternal articulations. 



The upper border of the sternum is on a level with the lower 

 border of the second dorsal vertebra, and about 2 inches 

 distant from it. The junction of the manubrium with the body 

 of the sternum forms a marked prominence Ludwig's angle ; at 

 this point the second costal cartilage articulates, 



The Lung's. The apex of the lung extends upwards for one 

 to two inches above the anterior extremity of the first rib, and is 

 indicated by a curved line drawn from the upper border of the 

 sterno-clavicular articulation to the junction of the inner and 

 middle thirds of the clavicle, the highest part of the curve being 

 from J inch to 1^ inches above the clavicle. The apex of the 

 right lung is J inch higher than that of the left. The subclavian 

 artery lies on the cervical pleura covering the apex of the 

 lung. 



The anterior border of the right lung is indicated by a line 

 drawn from the upper border of the sterno-clavicular articulation 

 to the centre of the manubrium, and thence vertically downwards, 

 slightly to the left of the middle line, to the level of the sixth' or 

 seventh costal cartilage. 



The anterior border of the left lung is indicated by a similar 

 line as far as the fourth costal cartilage ; thence along the lower 

 border of the cartilage to the parasternal line, then downwards, 

 to the upper border of the sixth costal cartilage in the para- 

 sternal line. 



The lower border of the lung is the same on both sides, and is 

 indicated by a line drawn from the lowest point of the anterior 

 border along the sixth costal cartilage to the mid-clavicular line, 

 and then curving slightly downwards across the chest to the 



