CHAPTER XVI 



SKELETON AND MUSCLES 



152. Skeleton and Muscles. — Muscles which serve to 

 move the body cover and protect the skeleton of man. The 

 more delicate organs of the body are protected further 

 — the heart and lungs by the ribs, and the brain by the 



cranium. The skeleton 



nasal bones 



clavicle (collarbone! 

 shoulder blode 



nu rntrus 



vCrani u m 

 • V-j- M a' ar (cheek) bone 



-superior maxillary bones 



■ mferior 



and muscles of man are 

 similar to the correspond- 

 ing parts in the frog and 

 the dog. Certain tech- 

 nical differences are 

 noted by anatomists, but 

 in general plan or struc- 

 ture and in their func- 

 tions, the skeleton and 

 muscles are alike in all 

 the higher animals. 



153. The Skeleton. — 

 Unlike the rest of the 

 body the skeleton proper 

 is hard. It consists of 

 bone and a compara- 

 tively soft substance 

 known as cartilage, or gristle. There are cells in the 

 bones just as there are cells in the liver, the muscles, and 

 in the nervous system. So, like the other parts of the 



184 



JV— phalanges 



Figure 191. — Skeleton. 



