TEOPICAL ABSCESS OF THE LIVEE. 409 



inferior vena cava or bile ducts. The pericardium is perforated 

 in some instances, or pus, burrowing between the layers of the 

 coronary ligament, may travel down behind the peritoneum and 

 reach the pelvis of the right kidney. 



Pain on the top of the shoulder may occur in liver abscess. 

 The pain is localised in the angle between the clavicle and 

 acromion process. The phrenic nerve which is distributed to 

 the diaphragm and in part to the liver, arises chiefly from the 

 fourth cervical root, and filaments from the same root help to 

 form the supraclavicular branches of the cervical plexus. This 

 anatomical fact may account for the peculiar localisation of the 

 referred pain. 



The base of the right lung is hollowed out and fits on the 

 convex surface of the liver like a cap, the diaphragm and pleura 

 intervening. A large abscess, projecting from the upper part of 

 the right lobe of the liver posteriorly, may give rise to a dome- 

 shaped area of dulness which encroaches on the pulmonary 

 resonance. If fluid is effused in the intervening pleural sac the 

 characteristic outline of the dulness is obscured. A dull area of 

 similar outline may be found in the axilla when the abscess is 

 situated more laterally. The normal lower border of pulmonary 

 resonance is a horizontal line which corresponds to the sixth 

 costal cartilage in front, the sixth rib in the nipple line, the 

 eighth rib in the axilla, the tenth rib in the scapular line, and 

 the tenth dorsal spine posteriorly. When the liver is enlarged 

 in the upward direction the base of the lung is pushed upwards, 

 but the level of the lower border of the pleural sac remains prac- 

 tically unchanged. The lower limit of the pleura extends from 

 the mid-line in front across the seventh costal cartilage ; it 

 reaches the eighth rib in the nipple line, the lower border of the 

 tenth rib in the axilla, and the level of the twelfth dorsal spine 

 behind. The fixed position of the lower limit of the pleura under 

 all circumstances is accounted for by the presence of the strong 

 phrenico-pleural ligament which passes between the point of 

 attachment of the diaphragm to the adjacent costal cartilages 

 and the lower limit of the pleural sac. 



