PILOCAEPHSTE AND ATROPINE O_!l 



dose of piloearpine. AVait for the action of the drug to 

 become well developed. How is the heart affected I Stimu- 

 late one vagus nerve and see if this slows or accelerates 

 the heart. If it beats faster or if the pressure rises how 

 do you explain the result? Is this a natural phenomenon 

 or have the drugs caused it in some way? When the action 

 of piloearpine is well marked (give more of the piloearpine 

 if absolutely necessary) inject one cubic centimeter of 

 atropine solution (one cubic centimeter equals one milli- 

 gram). Do you get typical results on the heart and blood- 

 pressure! Stimulate the chorda tympani and see if secre- 

 tion follows. Another smaller dose of atropine may be 

 given if the animal will probably tolerate it well. 



Now stimulate the oculomotor nerve again and see if 

 you get a contraction of the pupil. Stimulate the vago- 

 sympathetic in the neck and see if the pupil dilates. If 

 time permits dissect out the oculomotor nerve on the left 

 side and stimulate it to see if contraction of the pupil will 

 occur. Kill the animal with a big dose of atropine. If 

 you do not have enough solution to do this (how much does 

 it take?) then inject nicotine in addition. Examine the 

 respiratory tracing just after the piloearpine was injected. 

 Do you note a decrease in the amplitude of the respiration 

 with some difficulty in either expiration or inspiration? 

 How do you account for this? Is it central or peripheral? 

 How did the atropine affect this? Did the atropine act 

 centrally or peripherally ! Could you obtain such phe- 

 nomena as this in an animal whose head had been removed 

 from the body? 



After the animal is dead pick up one vago-synipathetic 

 nerve trunk in the neck and follow it up toward the base 

 of the skull. Dissect out the superior cervical ganglion 

 and determine its relations to the surrounding structures. 

 From this ganglion sympathetic fibers pass to the various 

 organs, glands, involuntary muscles, etc., of the head. (See 

 Fig. 243.) 



