THE KIDNEYS. 641 



are seen to ooze out. They are convoluted tubes, in the 

 cortex,, called the tubes of Ferrein, intertwining here with 

 the venous and arterial capillaries, and ending either in 

 loops or co3ca ; while in the pyramids or cones these tubes 

 pursue a straight course. 



The papillae are surrounded by funnel-like formations of 

 a fibre-mucous character, called infundibula. The papillae 

 are sometimes more numerous than the infundibula, in 

 which case two or more of the former are found to one of 

 the latter. The infundibula come together or run into 

 each other so as to form three compartments one in the 

 middle, and one at each end of the kidney, which, from 

 their cup-like form, are termed calyces, and these calyces, 

 by their union, expand into the oval cavity, at the inner 

 margin of the hilus, constituting the pelvis of the kidney. 



The arteries of the kidneys are the renal or emulgent, 

 and come from the aorta, at right angles. Each divides 

 into six or more branches, which enter the fissure of the 

 kidney, and then sub-divide into numerous minute vessels 

 which go between the tubuli to the cortex, and form nu- 

 merous inosculations, constituting a capillary net-work. 

 The veins correspond to the arteries, though they are 

 larger. They pass out of the kidney at the fissure, and go 

 to the vena cava ascendens. The left renal vein is longer 

 than the right, and passes in front of the aorta. 



The lymphatics are described as numerous, and go to the 

 lumbar glands. 



The nerves come from the solar plexus, lesser splanchnic, 

 and lumbar ganglia of the sympathetic, and are traced 

 along with the arteries. 



Renal Capsules, (capsulce renales.) These bodies are two 

 in number, and are also called supra-renal or atra-biliary 

 bodies. They are situated at the superior extremity of 

 each kidney, being attached by cellular structure and 

 blood-vessels. Their form is triangular, with the base con- 

 cave, and resting upon the kidneys. Their color is of a 

 yellowish brown, and their size is variable, being much 

 larger in the foetus than in the adult. 

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