THE URETERS. 177 



Malpighian Tufts, are capillary plexuses within the Malpighian bodies. 

 From them arise the 



Efferent Vessels, whether arterial or venous, is undecided. They form 

 Venous Plexuses, on the convoluted uriniferous tubes. 



Stars of Verheyen, are venous plexuses of stellate form, situated on the 

 surface of the kidney, beneath its capsule, joining to form the 



Interlobular Veins, from the cortical portion ; which with the 



Vena Recta, from the medullary pyramids, making 



Venous Arches, over the bases of the pyramids, finally meet in the- 



Vents Proprice Renales, and they end in the 



Renal Vein, which empties into the inferior vena cava. 



Whence are the Nerves of the Kidney derived ? From the Renal 

 Plexus, which is formed by filaments from the solar plexus and the lesser 

 splanchnic nerve. 



THE URETERS. 



What is the Ureter ? The excretory duct of the kidney, forming, by its 

 upper expanded portion, the cavity of that gland. It is a musculo-membra- 

 nous tube, 16 to 18 inches long, as large as a small goose-quill; and ends 

 at the base of the bladder, into which it opens obliquely by a constricted 

 orifice, about 2 inches from the orifice of its fellow. The ureter commences 

 in the 



Calices, 7 to 13 small tubes, embracing the papillae of the kidney, and 

 joining to form the 



Infundibula, 3 or 4 in number, which unite in the 



Pelvis, a funnel-shaped dilatation of the upper portion of the ureter. 



Describe its Course. It descends obliquely inwards along the posterior 

 wall of the abdomen, enters the posterior false ligament of the bladder in the 

 male, and that of the uterus in the female, through which it passes forwards 

 and inwards to the posterior angle of the trigone vesicae, lying between 

 the muscular and mucous coats of the bladder, for about three-fourths 

 of an inch. 



What are its Relations ? It lies upon the psoas muscle, behind the peri- 

 toneum and below the spermatic vessels, over the common iliac or the external 

 iliac artery, behind the ileum on the right side, behind the sigmoid flexure 

 on the left. The right ureter lies close to the outer side of the inferior 

 vena cava. 



Describe its Structure. The ureter has 3 coats a fibrous, a muscular, 

 and a mucous ; the epithelium of the mucous coat is different from that 

 of the urethra, the bladder, or the uriniferous tubes, being spheroidal in 

 shape. 

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