OUR BODIES AND HOW WE LIVE 



FIG. 30. A Broken Radius. 



60. Repair of Broken Bones. When a bone is broken, 

 blood trickles out between the injured parts, and after- 

 wards gives place to a sticky, watery fluid, which gradually 

 becomes thicker, like sirup or jelly. This is 

 slowly replaced by a new bone structure, and 

 forms a kind of cement to hold together the 



broken ends. 



Nature does not 

 spare her healing 

 cement. The ex- 

 cess bulges out 

 around the place 

 of union, over which a bunch may be felt under the skin 

 for years. In young people, a broken bone will knit together 

 in two or three weeks ; while in grown-up people six weeks or 

 more will be required. In 

 aged persons, a broken 

 bone may prove a tedious 

 and often a serious matter. 

 When a bone is broken, 

 the ends tend to "ride" 

 over each other, because the 

 muscles tend to pull the 

 broken portions apart; 

 hence the need of a surgeon 

 to " set" the bone by draw- 

 ing the injured parts into place, and keeping them in 

 position by splints and bandages properly applied. 



After a bone has been once broken, it is fragile for some 

 time, and great care should be taken, especially with chil- 

 dren, for fear that it may be broken a second time before 

 it has properly healed (Sec. 405, Figs. 179 and 185). 



FIG. 31. A Broken Clavicle. 



