TOBACUM — TOBACCO 201 



TOBACUM — TOBACCO 



Tobacco is the leaves of Nicotiana tohacum, subjected to a process 

 of fermentation to remove certain proteins and fats that make the 

 smoke disagreeable and then to a second fermentation during which a 

 considerable amount of nicotine is lost and aroma developed. It con- 

 tains a liquid, oily, volatile alkaloid nicotine, allied alkaloids and a 

 volatile oil, to which its aroma is due. 



Action. Tobacco has an action similar to conium, but has less 

 effect upon the motor nerve endings. Its most important action is 

 upon the sympathetic nerve cells which are at first stimulated, then 

 depressed and finally paralyzed (Dixon). 



Externally and Locally. Tobacco is an antiseptic and para- 

 siticide. 



Digestive System. Tobacco or nicotine is a gastrointestinal 

 irritant. It increases the secretion of saliva from irritation of the 

 drug in the mouth. It causes nausea, vomiting and increased peri- 

 stalsis either from direct irritation or after absorption. Toxic doses 

 cause the usual symptoms of gastro-enteritis. 



Circulatory System. The heart is first slowed through stimula- 

 tion of the vagus center and ganglia and then accelerated through de- 

 pression of the vagus center and stimulation of the sympathetic 

 ganglia. The final result is always an acceleration of the pulse due 

 to a lack of inhibition. Blood pressure is increased for a short time 

 on account of stimulation of the vasoconstrictor center and intense 

 stimulation of the cells of the sympathetic ganglia, but is soon fol- 

 lowed by a fall in pressure, due to a depression of the same struc- 

 tures. All these actions finally result in vasodilation, fall of blood 

 pressure and acceleration of the heart. 



Respiratory System. The respiratory center is first stimu- 

 lated, then depressed and finally paralyzed by large doses. 



Nervous System. Nicotine first stimulates the central nervous 

 system, but this soon gives way to depression. There is no marked 

 action upon the brain. Its aption upon the medulla is shown through 

 its action upon the various centers. These are first stimulated and 

 then depressed. The cord is not so strongly influenced as the medulla 

 but there is a transitory stimulation of the reflex centers, causing 

 twitching, convulsions, etc., soon giving way to depression and, in 

 toxic doses, paralysis. All sympathetic ganglia are briefly stimu- 

 lated, then depressed. 



Eye. The action of nicotine upon the pupils is not constant. In 

 the dog and cat it is dilated for a brief period, constricted in the 

 rabbit and in man constricted at first, then followed by dilatation. 

 The difference probably depends upon whether the sympathetic 

 (dilator) or occulomotor (constrictor) ganglia are affected. 



Glands. The secretions from the salivary, sweat and bronchial 



