I 5 8 



OUR BODIES AND HOW WE LIVE 



important changes in the structure of the heart. As with 

 the walls of the arteries, so with the heart : the prolonged 

 use of alcohol may cause a deposit of fatty 

 tissue in place of the muscular fibers. 



This diseased condition, known as " fatty 

 degeneration," may seriously interfere with 

 the heart's power of contraction. The walls 

 may become much thicker and the ventricles 

 smaller from this deposit of fat, and thus 

 the overtired organ may fail in its efforts 

 to pump forward the blood which rushes in 

 from the auricles. 



Alcoholic excess may also cause an over- 

 growth of adipose tissue upon the surface 

 of the heart which may seriously interfere 

 \\ I i'W I ! with the normal cardiac action. 



Again, the ventricles may become much 

 too large, and from lack of proper elasticity 

 may be unable to pump forward the blood. 

 All these conditions are apt to cause the 

 valves to lose their suppleness, and may 

 cause death by what is known as sudden 

 heart failure. 



218. Effect of Tobacco upon the Heart. 

 The nicotine of tobacco acts to partially 

 paralyze the nerves that control the heart's 

 FIG. 99. Artery in action. Under its influence the move- 

 the Front of the ments o f tne neart are irregular, now feeble 



Right Leg. 



and fluttering, now thumping with appar- 

 ently much force. Frequently there is severe pain about 

 the heart, often dizziness with gasping breath, extreme 

 pallor, and fainting. 



