^_l"ilH 



Fig. 3-3. Rhythmic peristaltic contractions of intestinal muscle 

 of the cat, Felis; frequency is recorded as abscissae from left to 

 right and amplitude as ordinates. From a to b, the muscle is in 

 Ringer's solution; then at b, and again at/, blood from an "excited" 

 cat, that had been barked at by a dog for some time, is added and 

 the contained adrenaline causes almost immediate and quite 

 prolonged inhibition of peristalsis. At d, peristalsis is restored by 

 changing the perfusing fluid to one containing blood from a "quiet" 

 cat, in which adrenaline secretion had not been stimulated (from 

 Cannon, 1915). 



Fig. 3-4. Smooth muscle contraction in isolated rat uterus, showmg 

 frequency as abscissae, and amplitude as ordmates. The t res h 

 extract of the neurohypophysis, containing °f ™^;^' ^"J^^'^^, 

 at the time indicated by the arrow on the l-^J'/f-^/X' 

 rhythmic contractions. The marked time mterval is 10 mm. (alter 

 Trendelenburg in Buddenbrock, 1950). 



