42 



GENEEAL ACTIONS OP DEUGS 



and in motor excitement, particularly in epileptiform con- 

 vulsions of dogs. 



II. — Dbugs Acting on -the Spinal Cobd. 



The functions of the cord consist in the conduction of 

 sensory impulses forward to the brain and of motor impulses 

 backward to the muscles ; in the origination of nervous 

 force in centres controlling certain functions (sexual, sweat- 

 ing, etc.) ; and in reflex action by which the cord transmits 

 impulses from sensory to motor tract of the same side oi 

 the body, or laterally, from sensory to motor columns on 

 opposite sides. 



While drugs probably influence the various centres in 

 the cord, our knowledge of their action is chiefly limited to 

 that exerted on the motor cells of the inferior cornua. 



If a drug stimulating the motor cells of the cord is 

 given experimentally, slight peripheral irritation will reflexly 

 cause convulsions, and, if the cord is severed from the brain, 

 the same phenomena appear. 



i (A) Drugs stimulating the motor cells of the inferior cornua. 



Ergor [ Primary action 



Strychnine Ammonia 



Bruoine Ansesthetics 



Thebaine 



Uses. — Strychnine is employed in paraplegia resulting 

 from diseases of the spinal cord after irritation caused by 

 the lesion has passed away. 



(B) Drugs depressing the motor cells of the inferior cornua. 



Physostigmine 



Bromides 



Ergot 



Nitrites 



Grelsemiimi 



Emetine 

 Turpentine 

 ^- ( Sodium 

 "^ •< Potassium 

 CO ( Lithium 



ro 1 Antimony 

 "d i Silver 

 !» (zinc 

 Saponin 



Chloral 

 Morphine 

 Apomorphine 

 Alcohol 



Ether 

 Chloroform 

 Camphor 

 Carbolic acid 



Nicotine 

 Veratrine 

 Mercury 

 Arsenic 



Digitized by Microsoft® 



