1006 



THE URIXARY ORGANS 



from one-seventh to one-fifth less. In tlie eliild tlie orojan is relatively large, hut 

 its i)ernuinent relation to the hody-weight is usually attained at the end of tlie 

 tenth year of life. 



It "offers for il(scrii)tion two surfaces, two extremities, and two horders. Tlie 

 anterior or visceral surface is convex, and looks obliquely forwards and out- 

 wards; the posterior or parietal surface, less eonvix than the anterior, looks 

 inwards and backwards; the rountled upper extremity is usually somewhat 

 larger than the lower, and is placed about half an inch nearer to the median 

 sagittal i»lane of the body. The external border is narrow and convex. The 

 internal border (or surface), looking forwards, inwards, and slightly downw'ards, 

 is relatively broad, and is fissured vertically in the middle third of its length by 

 the hilum. 



The hilum is a slit-like aperture bounded in front and behind by two rounded 

 lips of variable and unequal thickness. The posterior lip is nearer to the middle 

 line than the anterior, and lietween the tw^o pass the renal vessels and nerves, the 

 duct, and a quantity of fat-bearing connective tissue. The sinus (fig. 609), 

 occupied by the structures just named, is narrowest near its entrance, and about 



FiCx. G08. — DiAGEAM SHOWING RELATION OF KlDXEY TO CAPSULE. (W. A.) 



TRANSVERSE COLON 



DESCENDING COLON 



PERITONEUM 



FATTY CAPSULE 



PERITONEAL CAVITY 



Diaphragmatic 

 fascia 



Parietal muscle ' 



SUBPERITONEAL TISSUE FATTY CAPSULE lienal lesucls embedded in subperitoneal tissue 



CUT EDGE OF 

 PERITONEUM 



Muscular fibre in 

 subperitoneal 

 tissue 



PANCREAS 



Sup. tnesentefic vein 

 DUODENUM 

 Vena cava 

 LYMPHATIC GLAND 



LUMBAR VERTEBRA 



an inch (25 mm.) in depth. Its fundus is pierced by the renal vessels and nerves, 

 and l)y the uriniferous tubules; and gives attachment to the primary branches 

 (calices) of the duct. 



Investment and fixation. — The entire organ is enveloped and supported by a 

 kind of capsule of fat-bearing connective tissue derived from the parietal layer of 

 the subperitoneal fascia (tig. 608). The adipose element is usually small at birth, 

 but tends to increase about puberty and during adult life. ^Mien it is scanty, the 

 sub))eritoneal investment often appears as a transparent fascial })lane, which in 

 renal operations may be mistaken for peritoneum or fascia transversalis; or if the 

 fat be excessively developed over the posterior asi)ect of the organ, it may form a 

 kind of hernial protrusion into the parietal incision. Should the sustentacular 

 power of the fatty cajisule become impaired by atrophy from wasting disease, by 

 the pressure of a pregnant uterus or tight stays, or from any other cause, the 

 phenomenon of movable or wandering kidney may be set up by slight external 

 violence, the organ tending to shift its place as far as the attachment of its vessels 

 to the main trunk will ])ermit. 



Position and relations. — The kidney is commonlv said to lie in the lumbar 



