ABDOMINAL CAVITY 527 



The average length of the kidney is four inches ; its 

 breadth two and a half inches ; and its average weight four 

 and a half ounces in the male, but somewhat less in the 

 female. It is a solid organ, very pliable, and of a brownish- 

 red colour. The left kidney is, as a rule, slightly longer 

 and narrower than the right kidney. 



Form of the Kidney. This is so characteristic that the 

 term "reniform," or "kidney-shaped," has become common 

 in descriptive language. The anterior surface looks laterally 

 and forwards, and presents impressions corresponding to the 

 viscera in contact with it ; whilst the posterior surface is directed 

 medially and backwards, and is moulded accurately upon the 

 parts which support it. The extremities are round, but the 

 superior end is usually thicker and more massive than the 

 inferior. The lateral border, smooth and convex, is directed 

 backwards and laterally - r whilst the medial border is concave, 

 and looks medially and forwards. The true form of the 

 kidneys can only be seen in cases where they have been 

 carefully hardened in situ, 



The kidneys present many changes in form, according to 

 the amount and the kind of pressure which is exerted upon 

 them by contiguous viscera. In most cases, however, and 

 on both sides there is on the anterior surface of the organ 

 a point of maximum convexity a place where the kidney 

 substance is raised in the form of a marked prominence or 

 bulging. Above and below this eminence the anterior surface 

 falls away towards each extremity, in the form of an inclined 

 or sloping plane of greater or less obliquity. These impressed 

 districts indicate pressure exercised on the anterior surface 

 of the kidney in two directions, and the intervening eminence 

 is the result of this pressure and counterpressure. This 

 characteristic is more constant and better marked in the case 

 of the left kidney. 



Upon the upper inclined plane of the anterior surface of the left kidney 

 are placed the left suprarenal gland, the stomach, the spleen, and the 

 pancreas. These exercise a downward and backward pressure, chiefly 

 through changes in the condition of the stomach. Upon the inferior 

 inclined plane of the left kidney the counterpressure is produced by the 

 intestinal canal, which, as a rule, presses upwards and backwards. 



Resting upon the upper inclined plane of the right kidney is the liver, 

 whilst in contact with the lower inclined area is the colon. The colon 

 presses on the kidney in an upward and backward direction. To this 

 pressure the liver offers a passive resistance, except perhaps in the case 

 of the slight influence which it conveys in a downward direction from the 



