12G MEDULLA 



conditions are in every case identical with those observed after 

 stimulation of the hypogastric nerves. These nerves carry 

 both motor and inhibitory fibers to the uterus and hence the 

 relative strength of these two sets of fibers determines the re- 

 action in any given case. 



EFFECTS OF EPINEPHRINE ON OTHER ABDOMINAL VISCERA 



The spleen is very sensitive to epinephrine, contracting 

 even with minute doses. This contraction involves arteries, 

 muscular capsule, and trabeculae. 



The gall bladder and sphincter of Oddi are relaxed by epi- 

 nephrine; the bile ducts are contracted. 



Epinephrine causes little effect on the bladder of most ani- 

 mals but in the cat and monkey relaxation (paralleling the 

 effect of stimulating the hypogastric nerves) occurs, while con- 

 traction follows epinephrine injections in the goat and ferret. 



Similar differences result from the action of epinephrine on 

 the ureter. Contraction is observed in the cat, guinea pig, 

 monkey, and man; contraction or relaxation in the dog; and 

 no response in the ferret. 



Epinephrine causes relaxation of the tunica dartos, contrac- 

 tion of the vas deferens, seminal vesicles and vagina, and in- 

 creased tone of the prostate. 



PILOMOTOR MUSCLES 



Smooth muscle in general, if contracted by sympathetic 

 stimulation, is readily made to contract by epinephrine. The 

 pilomotor fibers, however, are an exception to this rule. Al- 

 though readily affected by sympathetic stimulation their re- 

 sponse to epinephrine in most animals is slight. 



The apparently discordant effects of epinephrine on the skin 

 muscles and arrectores pilorum are harmonised, according to 

 Elliott, 177 when one considers the varying functional use of 

 these muscles in different animals. Thus epinephrine has little 

 effect on the hairs of a cat's back, but causes marked action on 



