DUCTS OF FERREIN. DUCTS OF BELLINI. 



123 



^^' 



which uniting with the veins form other Fig. 153. 



glomerules contributes to the formation of 

 the dehcate venous plexus, wliich sur- 

 rounds the tortuous uriniferous tubes in the 

 conical part of the kidney. 

 — The colloidal, medullary or tubular 

 portions of the kidney, are from twelve 

 to eighteen in number. The bases of these 

 are rounded, and turned to the cortical 

 matter which covers them to the thickness 

 of two lines, and dips in for a much 

 greater depth between their rounded margins. The arteries 

 and veins send up their ramifications to the cortical mat- 

 ter, between these different conoidal bodies so as to separate 

 them from each other. The conoidal bodies terminate in the 

 caliceSj'in little nipple-like projections, called papilla renales. 

 At the apex of these, there is usually a depression, called 

 foveola. There are usually but ten or twelve of these papillas, 

 two of the conoidal bodies terminating as before described in several 

 places in a common papilla. Theconoidal bodies being pyrami- 

 dal in their shape, are sometimes called the pyramids of Malpighi. 

 — Each of these conoidal bodies or pyramids, is composed of an 

 immense number of minute tubes, {tuhuli uriniferi,^ which termi- 

 nate by a small number of orifices on the surface of its papilla. 

 — The tubes originate in the cortical portion, in their course 

 through which they are serpentine and tortuous, and are called 

 the ducts of Ferrein (dacti Ferreinei ;) the same ducts, as 

 they pass from the cortical matter to the papilla become straight, 

 and are called the ducts of Bellini, from two anatomists who 

 devoted much attention to the structure of the kidney. Ferrein 

 ascertained that the o-eneral convergence , of each cone or 



* Plan of the venal circulation after Mr. Bowman, a, Branch of the venal 

 artery givingoff twigs to the raalpighian bodies. 1, A twig sent to one of these 

 bodies or gloraercules(?n). From the glomercule {m) the uriniferous tube is .seen 

 taking its tortuous course to {t), after which it becomes straight. 2, 2, Various 

 efferent veins forming a plexus (p, p.) about the tubuli urinileri. This venous 

 plexus transmits its blood, by a larger branch (f) which runs between the pyra- 

 mids and by the side of the arterial branches, to empty into the great venal 

 vein. — 



