SUPRARENAL— SPERMATIC 561 



THE SUPRARENAL ARTERIES 



The capsular or suprarenal arteries are derived from three sources, and 

 are named as follows: — (1) Superior suprarenal; (2) middle suprarenal; and 

 (3) inferior suprarenal. 



(1) The superior suprarenals, one on each side, are usually derived from tlie 

 phrenics, and clescend to the su})rarenal bodies. 



(2) The middle suprarenals, or suprarenals proper, come off one on each side 

 from the aorta, just above the first lumbar artery, and pass transversely outwards 

 to the suprarenal bodies, across the crura of the diaphragm a little above the renal 

 arteries. In the fcjetus they equal the renals in size. In the adult they are mucli 

 smaller. 



(3) The inferior suprarenals are branches of the renals. They ascend, one on 

 each side, to the suprarenal bodies. 



The suprarenal veins, usually one on each side, terminate as a rule on the left 

 side in the left renal; on the right side, in the inferior vena cava. 



For the distribution of the suprarenal vessels within the suprarenal capsules, see 

 page 1014. 



THE SPERMATIC ARTERIES 



The spermatic arteries come off from the front of the abdominal aorta. 

 They diverge from each other as they descend over the aorta and psoas muscle to 

 the deep or internal abdominal ring, where they are joined by the vas deferens, 

 and, passing with it through the inguinal canal and out of the external or 

 superficial abdominal ring, run downwards into the scrotum in a tortuous course 

 to the testicle. They terminate in branches to the epididymis and bocl}- of that 

 organ. Within the abdomen they lie beneath the peritoneum, and cross in their 

 descent over the ureter and distal end of the external iliac artery; the right being 

 superficial to the vena cava, and behind the termination of the ileum; and the 

 left beneath the sigmoid flexure of the colon. In the inguinal canal and in 

 the scrotum the spermatic veins lie in front of the artery, and the vas deferens lies 

 behind it. 



In the foetus these vessels pass transversely outw^ards to the testicle, which in 

 early foetal life lies in the loin in front of the kidney; but as the testicles descend to 

 the scrotum, the vessels become elongated, and are drawn with the testicle into the 

 scrotum. 



The spermatic arteries give off the following branches: — (1) Ureteral; (2) cre- 

 masteric; (3) epididymal; and (4) testicular. 



(1) The ureteral are small branches given off to the ureter as the si")ermatic 

 artery crosses it. They anastomose with the other ureteral branches derived from 

 the renal, common iliac, and vesical arteries. 



(2) The cremasteric are small branches given off to the cremaster muscle; 

 they anastomose with the cremasteric branch of the deep epigastric. 



(3) The epididymal are distributed to the epididymis, and anastomose Mith 

 the artery of the vas. 



(4) The testicular are the terminal branches of the spermatic; they perforate 

 the tunica albuginea posteriorly, and are distributed to the body of the organ in 

 the way mentioned in the section on the Testicle. 



Chief variations in the spermatic arteries. — (A) One or both may be wanting, the testide 

 being then supplied by branches from the vesical or prostatic arteries jiassing under the arch of 

 the pubis. (B) One or both may arise from the renal, more rarely from the suprarenal. (C) 

 One may come off higher tliaii the other. (D) They may come off from a common stem. (E) 

 One or both may be double in the whole or part of "their course. (F) The right spermatic may 

 run behind instead of in front of the inferior vena cava. 



36 



