KIDNEYS. 



341 



ouo beiDg longer and narrower than tho right. From perverted 

 <levelopmeut, tho kidney of the horse is sometimes lobulated. 



^ The kidney presents two surfaces and a circumference. The 

 surfaces are smooth, the superior one being flattened, and 

 attached to the muscles by cellular tissue ; the inferior one is 

 convex, covered by and attached to the peritoneum. The cir- 

 cumference is divided into three borders; 

 anterior, posterior, and internal. The 

 two former are convex; to the first 

 is attached the suprarenal capsule. 

 The internal border is slightly concave, 

 being deeply notched in the centre, 

 forming the " hilus, which leads to a 

 cavity called the sinus. The vessels, 

 nerves, and duct of the kidney join it 

 in or about the hilus. 



The kidney is made up chiefly of 

 the tubes of the gland, termed the 

 uriniferous tubes, with blood-vessels 

 and nerves, and connective tissue ; it 

 is invested by a fibrous capsule, and 

 contains a cavity known as the pelvis 

 of the kidney. The capsule invests 

 the entire organ, entering the hilus 

 and covering the sinus, vessels, and 

 duct. It consists of thin, smooth, 

 fibro-areolar tissue, intimately con- 

 nected with the surface of the gland 

 by minute fibrous processes and blood- 

 vessels. On making a horizontal 

 section of a kidney, it is found to 



consist of an external or coHical, 



, • , 1 7 77 V c cc, Capillary plexuses formed by effer- 



and an mternal or medullary sub- e^t^eggeig.d.Twigs from renai artery; 



stance. The cortical layer is situated HH. Larger tubea of Bellini;f, smaller 

 •' branch of the same. 



beneath the capsule, sending pro- 

 longations inwards into the medullary portion. It is dark 

 reddish-brov/n and friable, consisting of minute blood-vessels, 

 convolutions of the uriniferous tubes^ lymphatics, and nerves, 

 united by areolar tissue. On examining the section with or 

 without a lens, numerous minute red points are seen in the 

 coitical portion, the Malpighian bodies. Each consists of 



Fio. 121. 

 structure of the kidney. A A A, Large 

 branches of renal artery ; a a, Affer- 

 ent vessels ; B B, Malpighian bodies ;- 



