THE UROGENITAL SYSTEM 



The urogenital apparatus (Apparatus urogenitalis) includes two groups of 



organs, the urinary and the genital. 



The urinary organs elaborate and remove the 

 chief excretory fluid, the urine. The geni- 

 tal organs serve for the formation, develop- 

 ment, and expulsion of the products of the 

 reproductive glands. In the higher verte- 

 brates the two apparatus are independent 

 except at the terminal part, which consti- 

 tutes a urogenital tract, and includes the 

 vulva in the female and the greater part of 

 the urethra in the male. 



THE URINARY ORGANS 



The urinary organs (Organa uropoiet- 

 ica) are the kidneys, ureters, bladder, and 

 urethra. The kidneys are the glands which 

 secrete the urine; they are red-brown in 

 color, and are situated against the dorsal 

 wall of the abdomen, being in most ani- 

 mals almost symmetrically placed on either 

 side of the spine. The ureters are tubes 

 which convey the urine to the urinary 

 bladder. The latter is an ovoid or piri- 

 form sac, which is situated on the pelvic 

 floor when empty or nearly so; it is a reser- 

 voir for the urine. The urine accumulates 

 in the bladder and is then expelled through 

 the urethra. 



Fig. 494. — General Dorsal View of Urinary 

 Organs of Horse. 

 /, Right kidney; 1' , left kidney; g, 2', ad- 

 renal bodies; 3. 3', ureters; 4. urinary bladder; 4', THE URINARY ORGANS OF THE 

 anterior end of bladder with cicatricial remnant of WOT^QTh 

 urachus; 4"> urethra; 5, aorta; 6, 6, renal arteries; 



7, 7, external iliac arteries; 5, 8, internal iliac ar- T*FTF K^TDT^rFY^ 



teries; 9, 9, umbilical arteries. (After Leisering's 



Atlas.) Each kidney presents two surfaces^ 



two borders, and two extremities or poles, 

 but they differ so much in form and position as to require a separate description 

 of each in these respects. 



The right kidney (Ren dexter) in outline resembles the heart on a playing 

 card, or an equilateral triangle with the angles rounded off. It lies ventral to the 

 upper parts of the last two or three ribs and the first lumbar transverse process. 

 The dorsal surface (Facies dorsalis) is strongly convex; it is related chiefly to the 

 diaphragm, but also to a small extent posteriorly to the iliac fascia and psoas 



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