1260 



THE UEO-GENITAL SYSTEM. 



the renal fascia by numerous connective tissue strands. These traverse the peri- 

 nephric fat and undoubtedly assist in fixing the kidney in its place. The paranephric 

 fat is present in greatest quantity behind the inferior part of the kidney, and in 

 this position the layer of fibrous tissue, separating the two masses of fat and 

 forming the posterior layer of the sheath of renal fascia, is usually well marked. 



Fixation of the Kidney. The kidney is not held in its place by any distinct 

 ligaments, or special folds of peritoneum, but its fixation depends, to a large 

 extent, on the pressure and counter-pressure which is exerted upon it by neigh- 

 bouring structures, and on its connexions with the fascia renalis above described. 



Posterior Relations and the Posterior Surface of the Kidney. The muscles 

 of the posterior abdominal wall on which the kidney rests are the psoas major, the 



Pleura 



Pleura 

 /Cms of 

 \ diaphragm 

 / 1st lumbar 

 \ vertebra 



12th rib 



(Lateral 

 lumbo- 

 costal arch 

 Diaphragm 

 Kidney 

 Liver 



Fat behind 

 colon 



Quadratus 

 lumboruin 



Iliac crest 



[liac crest 



FIG. 981. THE POSTERIOR RELATIONSHIPS OF THE KIDNEYS. The dotted lines indicate the contours of the 

 kidneys. The drawing is made from a model prepared by the late Professor Cunningham. 



quadratus lumborum, the diaphragm and the tendon of the transversus abdominis. 

 The abdominal surfaces of these muscles do not lie on the same plane, but slope 

 towards one another, and thus the bed on which the kidney rests is not flat. When 

 but little fat is present, the posterior aspect of the kidney adapts itself to the 

 inequalities of the surface against which it is placed, and so we may find on a 

 kidney which has been carefully fixed and hardened before it has been disturbed, 

 areas marked off for the different planes of these muscles. When such a kidney is 

 in position, slight ridges or elevations separating these areas correspond to the 

 angles along which the different muscular planes meet. These ridges can be 

 observed in the hardened kidney, after its removal from the body, but usually 

 they are not sharply defined, the angles between the muscular planes being 

 very obtuse. 



A kidney removed from the body after having been hardened in situ (Fig. 982 



