318 THE URINARY APPARATUS 



However, I will endeavor to make as clear as possible 

 their course. The tubules practically start in the cortex 

 as a capsule of Bowman, which surrounds the capillaries 

 (glomerulus) . The tubules run a very irregular and 

 distorted course, and finally end in straight tubules 

 which pass through the pyramids to empty into the 

 calices of the pelvis of the ureter. Bowman's capsule 

 is lined by flattened epithelial cells resting on a very 

 delicate basement membrane. The convoluted por- 

 tions of the tubules are lined with cuboidal epithe- 

 lium and the loops of Henle contain more or less 

 flattened epithelium. 



The Ureters. The ureters are two tubes, and con- 

 vey the urine from the kidney to the bladder. The 

 urine is collected from several minor calices, ten to 

 twenty in number, which open into the major calices; 

 the latter by their junction form the pelvis or dilated 

 portion of the ureter. It is on a line with the first 

 lumbar vertebra. 



The ureter proper is divided into an abdominal 

 portion (pars abdominalis) and a pelvic portion (pars 

 pelvina). They are 10 to 12 inches in length and - of 

 an inch in diameter. The walls are from 1 to 2 mm. 

 thick. 



The Urinary Bladder (Vesica Urinaris) . The bladder 

 is situated in the pelvic cavity, but in infancy and 

 when distended in the adult, extends into the hypo- 

 gastrium. It measures when moderately distended, 

 5 to 5J inches in length, 4J in width, and 3 inches 

 from before backward. It holds a pint of urine 

 without discomfort. The bladder presents a superior, 

 antero-inferior, and two lateral surfaces; a base or 

 fundus, and an apex or summit. 



The interior of the bladder shows the mucous mem- 

 brane thrown into rugae, the orifices of the ureters, and 

 the trigone, also the orifice of the urethra, which empties 

 the urine from the bladder. The ureteral orifices arc 



