HUMAN BODY 



work of the body were put together like the beams 

 and planks of a frame house, the whole mass would 

 be rigid and immovable ; we could not raise a hand to the 

 mouth, or put one foot before another. In order to attain 

 mobility the bony skeleton is made up of more than two 

 hundred separate pieces, joined together ; the points 

 where they meet are called articulations. An articulation 

 at which a considerable range of movement is permitted 

 is called a joint. The ends of bones which rub over one 

 another in a joint are always covered by a very smooth 

 layer of cartilage. 



The bony skeleton (Fig. 8) consists of an axial skeleton, 

 supporting head, neck, and trunk, and an appendicular 

 skeleton, supporting the limbs and attaching them to the 

 trunk. 



The Axial Skeleton. The fundamental portion of this 

 is the backbone, spinal column, or spine, partly seen at e 

 and c, Fig. 8, and represented isolated from the rest of the 

 bones and viewed from the left side in Fig. 9. It forms 

 an axis, on which the rest of the body is carried. On the 

 upper end of the vertebral column is the skull, a, b, Fig. 

 8, and attached by ligaments to the under surface of the 

 skull is the hyoid bone, to which the root of the tongue is 

 fastened. 



Attached to the sides of part of the spine are the dor- 

 sal ends of the ribs, slender bones which curve round the 



Why is the skeleton made up of separate bones ? What are 

 articulations ? \\%at is a joint? What covers the end of a bone in a 

 joint ? 



What are the chief divisions of the bony skeleton ? What parts 

 of the body does the axial skeleton support ? What is the appen- 

 dicular skeleton? 



What is the fundamental portion of the axial skeleton? What 

 does it bear on its upper end? What is the hyoid bone ? 



What are the ribs? Where are their ends fixed ? 



