KIDNEY. 



gradually diminiftied, and at lad difappear almoft entirely. 

 Their figure does not much referable any known objedl ; it 

 is foraewhat triangular, and bent from above downwards. 

 We may diftinguifh in them an anterior and a pofterior fur- 

 face, a fuperior and an inferior margin, an internal and an 

 external extremity. 



The anterior, which is alfo the broadcll furface, prefents, 

 a little above its middle, a tnmiverfe groove, which receives 

 the chief capfular vein : this correfponds, on the right fide, 

 to the inferior vena cava and the duodenum ; on the left, to 

 the fpleen and pancreas. The poftenor furface is in contatl 

 with the feini-lunar ganglion and the diaphragm. The in- 

 ferior edge, which from its breadth iias been dei'cribed as a 

 furface, is excavated obliquely from before backwards, and 

 from above downwards, and embraces tlie fuperior end of 

 the kidney. The fuperior margin, thin and convex, is rather 

 inchned inwards, correlponding to the liver on the right, and 

 to the fpleen on the left fide. In the extremities there is no- 

 thing remarkable : the inner is rounded and rather lower than 

 the outer, wliich is more pointed. The whole exterior is un- 

 equal, with an appearance of fmall lobes, and adheres to the 

 neighbouring parts by numerous veiTels, by nerves and by a 

 loole adipous fubflance, continuous with that which fur- 

 rounds the kidnies. This I'ublVance in moll cafes nearly re- 

 fembles the capfules themfelves in colour, fo that they may 

 be eafily overlooked in a fuperiicial examination. 



A kind of triangular cavity occupies the middle of the 

 capfule, with an oblong eminence, caufed by the courfe of 

 a vein projefting into it below : the fides of this hollow 

 often appear united by a kind of downy matter. It contains 

 a fluid of a reddifh colour in the foetus, yellow in young fub- 

 jedls, and brown in the adult. Its confiftence and quantity 

 are variable ; and it is coagulable by alcohol. It has been 

 afferted that this cavity may be inflated by the capfular vein ; 

 but Haller could not fucceed in attempting this in the human 

 iubjeft, allhoUpjh he accompliflted it in animals. Some deny 

 the exillcnce of a cavity, and others have afferted that it is 

 a vein. Haller faw it clearly fixteen times in the human fub- 

 je£l : it was not obfervable in three inftances. 



The colour is a brownifh-yellow, and dcepeft in the inte- 

 rior : it has more of red in the foetus and m children. The 

 form at that time is more rounded, the volume more confider- 

 able, and the fluid more abundant. Their confillence is 

 moderately firm ; more fo on the outfide than in the internal 

 portion, in the adult than in the child. They are compofed 

 of lobes divifible into lobules, which may again be reduced 

 into fmaller portions. The furrounding cellular iubltance 

 enters the organ and joins together thefe portions. In this re- 

 fpeft the ftrudture of the renal capfules refembles that of the 

 conglomerate glands ; but no excretory duQ. has been dif- 

 covered in them. 



Their arteries are numerous, and divided into fuperior, 

 ■which come from the lower diaphragmatic, middle from the 

 aorta or cse'iac artery, and inferior, which arile from the 

 renal. They anadomofc frequently, and feem to run on the 

 furfaces without entering the fubilance of the organs. The 

 veins are lefs complicated. There is always a large one on 

 each fide, produced from the inferior vena cava on the right, 

 and from the renal vein on the left fide. It enters the 

 groove of the anterior furface, and after running through 

 it, paffes into the neighbouring adipous fubftance, and to 

 the lower part of the diaphragm. The branches enter the 

 fubftance of the capfules, but probably do not open into 

 the cavities, as fome have fuppofed. 



Lymphatic velTels arife from all points of thefe organs, 

 and feveral join thofe of the kidney. On the right fide 

 they go to fome lymphatic glands placed round the vena 



cava, below the liver; or they are united with the abforb- 

 ents of the liver, and proceed with them to the thoracic 

 duA. On the left fide they enter glands placed in front of 

 the left crus of the diaphragm. 



The nerves of the renal capfules come from the casliac 

 ganglia and from the renal plexufes. 



Phyfwlogy of the renal Capfules. — The ufe of thefe bodies 

 is entirely unknown ; the phylioiogill or pathologift has not 

 hitherto noticed one faCl that can throw the fmalleft light 

 oil their office, or that can prove them to poffefs any 

 connection with any funition of the animal economy. 

 '' From an attentive confidcration of all circumftances,'' fays 

 Haller (Elem. Phyfiolog. lib. xxvi. fed. 4, J 14.) " I 

 can venture to affirm nothing further of thefe capfules, 

 than that they fecrete a fluid, which is more neceflary to the 

 life of the foetus than to that of the adult. I can draw no- 

 thing from comparative anatomy, except the probable con- 

 jednre, that they are made for important purpofes, as they 

 are found in fo many animals. They are large, and have a 

 large cavity in the carnivorous, as the tiger, and in fome 

 herbivorous animals. But in other herbivora they are 

 fmall, and the cavity is fmall in the voracious fliark.'' 



The urinary bladder, or mufcular and membranous re- 

 fervoir for the urine, is placed at the middle and anterior 

 part of the pelvis, behind the bones of the pubes ; before 

 the redlum in man and the uterus in woman ; below the fmall 

 inteftine, above the lower part of the redium, the vafa de- 

 ferentia and veficulas feminales in man, and the vagina in wo- 

 man. This is the naturdl lituation of the bladder in the 

 adult, but age and various circumllances produce changes 

 in this refpeCt, which it is important to obferve. In ihe 

 foetus the bladder is fituated almoll entirely out of the pelvis, 

 and reaches nearly to the navel, in the midll of the cellular 

 fubfl.aiice, v\'liicli occupies ttie lower and front part of 

 the abdomen, externally to the peritoneum. Hence it fol- 

 lows, that at this age its anterior furface is covered by the pe- 

 ritoneum only at the upper part, and that in the reft of its 

 extent it correfponds immediately to the offa pubis and the 

 refti and tranfverfi abdominis. It may accordingly be 

 opened above the pubes, even in its empty ftate, without 

 wounding the peritoneum. This peculiarity of pofition 

 ariles from the bladder being greatly developed in proportion 

 to the neighbouring organs, and efpecially from its being 

 very elongated, while the pelvis is fmall and very (hallow : 

 the upper aperture moreover is very oblique, and the rec- 

 tum, diltended by a large quantity of meconium, particu- 

 larly towards the latter periods of pregnancy, almoft en- 

 tirely fills the pelvis. As the cavity of the latter is deve- 

 loped, the bladder finks in it, and retires from the um- 

 bilicus. At three years of age it is faid to rife hardly more 

 than three fingers' breadth above the pubes, and at twelve 

 this is reduced to about half an inch : at eighteen it is faid 

 to be completely hidden behind the bone. Haller, however, 

 obferve."*, that he has feen the length of this vifcus remaining 

 even to the time of puberty, fo that it ftill projeded eonfi- 

 derably above the pelvis. In the adult, where the pelvis is 

 deep, and the bladder (horter, not exceeding the bulk of an 

 egg in its undiftended ftate, it never rifes above the pubes when 

 empty ; and even at other times is generally below the upper 

 edge of the bone. But wlien it contains a large quantity 

 of urine, it afcends and forms in the hypogaftric region a 

 very difcernible tumour, which rifes and increafes gradually, 

 in proportion as the quantity of contained fluid becomes 

 greater. It may reach in thefe cafes beyond the umbilicus. 

 It is contained in the abdomen in the latter months of preg- 

 nancy. Perhnps it may be inclined rather more backwards 

 in the fupine pofition of the body. It has foinetimes been 



contained 



