THE SUPRARENAL c.\ /'>7 'LES. 1137 



the extremities of the calices ; the circular fibres may be traced surrounding the 

 medullary structure in the same situation. In the ureter proper the muscular 

 fibres are very distinct, and are arranged in three layers an external longitudinal, 

 a middle circular, and an internal layer, less distinct than the other two, but 

 having a general longitudinal direction. According to Kolliker. this internal layer 

 is <>nly found in the neighborhood of the bladder. 



The mucous coat is smooth, and presents a few longitudinal folds which 

 become effaced by distension. It is continuous with the mucous membrane of the 

 bladder below, whilst it is prolonged over the papillae of the kidney above. Its 

 epithelium is of a peculiar character, and resembles that found in the bladder. It 

 is known by the name of " transitional " epithelium. It consists of several layers 

 of cells, of which the innermost that is to say, the cells in contact with the 

 U1 -i ne ar e quadrilateral in shape, with a concave margin on their outer surface, 

 into which fits the rounded end of the cells of the second layer. These, the inter- 

 mediate cells, more or less resemble columnar epithelium, and are pear-shaped, 

 with a rounded internal extremity which fits into the concavity of the cells of the 

 first layer, and a narrow external extremity which is wedged in between the cells 

 of the third layer. The external or third layer consists of conical or oval cells 

 varying in number in different parts, and presenting processes which extend down 

 into the basement membrane. 



The arteries supplying the ureter are branches from the renal, spermatic, 

 internal iliac, and inferior vesical. 



The nerves are derived from the inferior mesenteric, spermatic, and pelvic 

 plexr 



THE SUPRARENAL CAPSULES. 



The Suprarenal Capsules are classified, together with the spleen, thymus, and 

 thyroid, under the head of "ductless glands," as they have no excretory duct. 

 They are two small flattened glandular bodies, of a yellowish color, situated at the 

 back part of the abdomen, behind the peritoneum and immediately above and a 

 little in front of the upper part of each kidney ; hence their name. The right one 

 is somewhat triangular in shape, bearing a resemblance to a cocked hat ; the left is 

 more semilunar. and usually larger and higher than the right. They vary in size in 

 different individuals, being sometimes so small as to be scarcely detected ; their 

 usual size is from an inch and a quarter to nearly two inches in length, rather less 

 in width, and from two to three lines in thickness. Their average weight is about 

 a drachm each. 



Relations. The relations of the suprarenal capsules differ on the two sides of 

 the body. The ru/ht suprarenal presents on its anterior surface two areas: along 

 its upper and inner borders a depressed area, which is in contact in front with the 

 under surface of the right lobe of the liver, and along its inner border with the 

 inferior vena cava (Rolleston). and behind rests on the crus of the Diaphragm ; 

 over the remainder of the anterior surface is an elevated area, which is covered in 

 front by peritoneum passing from the upper part of the kidney to the under sur- 

 face of the liver, and behind rests on the upper and inner part of the kidney. 

 The left suprarenal is in contact by its anterior surface, superiorly, with the 

 spleen : below and internal to this it is in contact with the peritoneum forming 

 the lesser sac. which separates it from the cardiac extremity of the stomach; and 

 at its lower part it is covered by the pancreas and splenic artery, and is therefore 

 nit in contact with the peritoneum. By its posterior surface, at its outer and 

 back part, it rests upon the kidney, whilst below and internally it is in contact 

 with the left crus of the Diaphragm. 



Structure. The surface of the suprarenal gland is surrounded by areolar tissue 

 containing much fat, and closely invested by a thin fibrous coat, which is difficult 

 to remove on account of the numerous fibrous processes and vessels which enter the 

 organ through the furrows on its anterior surface and base. 



Small accessory suprarenals are often to be found in the connective tissue 



