THE ABDOMEN 703 



eleventh rib on a level with the eleventh thoracic spine. From this latter 

 point the line should proceed forwards and sUghtly upwards to a point about 

 ^ inch below the tip of the bony part of the tenth right rib. and finally upwards 

 and to the left to reach the starting-point. 



The liver is to a very large extent under cover of the lower ribs 

 and costal cartilages of the right side, the ensiform process, and 

 the sixth, seventh, and eighth, costal cartilages of the left side. 

 It is accurately moulded on the under surface of the diaphragm, 

 which separates it from the base of the right lung covered by pleura, 

 and the heart enclosed in the pericardium. The thin marginal part 

 of the base of the right lung, with its pleural investment, descends 

 in the angular interval between the diaphragm and the thoracic 

 wall, and so partially covers the liver, a relation which has to be 

 borne in mind in percussing the organ. In the right mammary 

 line the lung descends as low as the sixth rib, whilst the liver ascends 

 to the upper border of the fifth. In the right mid-axillary line the 

 limg descends as low as the eighth rib, whilst the liver ascends as high 

 as the seventh. In the right scapular line (inferior angle of scapula) 

 the lung descends as low as the tenth rib, whilst the liver ascends 

 as high as the ninth. The liver comes nearest to the surface 

 beyond the right costal margin and ensiform process. In the former 

 situation it projects about \ inch, and in the latter about 2 inches, and 

 in each situation is in contact with the anterior abdominal parietes. 



Various circumstances aflfect the position of the liver. ^ During respiration, 

 the hver descends in inspiration and ascends in expiration. In the horizontal 

 posture it ascends, and in the sitting or upright posture it descends. In 

 distension of the stomach and intestines, as well as in ascites, it ascends. In 

 right hydro-thorax, hypertrophy of the heart, and hydro-pericardium it 

 descends. Long-continued pressure, as in tight lacing, causes the liver to 

 be displaced downwards. Finally, when the abdomen proper is encroached 

 upon by the gravid uterus or by an ovarian tumour the liver is displaced 

 upwards. 



The liver has a reddish- brown colour, and presents for the most 

 part a smooth surface. It is firm to the touch, but under pressure 

 is friable, that is to say, easily crumbled. The dimensions of the 

 organ can only be stated approximately. In the transverse 

 direction (from right to left) it measures from 7 to 10 inches, the 

 measurement from before backwards at its right extremity being 

 about 6 inches, which also represents its vertical measurement at 

 the thickest part of the right lobe. Its weight in the adult ranges 

 from 45 to 60 ounces, or from 3 to 4 pounds, the weight in the female 

 being rather less, and its relation to the body weight being in the 

 proportion of one to forty in the adult. In early life the liver is 

 proportionately larger than in the adult, and in a child at the period 

 of birth its relation to the body weight is as one to twenty. 



Surfaces. — ^These are superior, anterior, inferior, right lateral, 

 and posterior. It is not to be supposed, however, that these 

 surfaces are all clearly separated from one another by well-defined 

 borders, only one margin being in reality distinct, namely, the 

 anterior border, which has a very sharp outline. 



