JOINTS AND LIGAMENTS. 



1. A joint is a place of normal contact between 

 bones. 



2. A joint is a natural breach in the continuity of 

 the skeleton. 



3. A joint consists of the approximation of the 

 articular parts of bones, covered by cartilage and held 

 in position by ligaments. 



Three elements are found in joints, bone, cartilage, 

 and ligaments. Bone has been described. Cartilage, or 



Hyaline Cartilage. Fibro-cartilage. Cartilage Cells. 



FIG. 70. DIAGRAM OF CARTILAGES. 



gristle, is a non-vascular structure, divided into two 

 kinds, temporary and permanent. The temporary car- 

 tilage is that which precedes the structure of bone; 

 thus the cartilaginous mold of the femur is first formed, 

 and subsequently converted into or displaced by the 

 bone elements proper. The permanent cartilage is 

 found covering the articular ends of bones, and gener- 

 ally persists as cartilage during the life of the 

 individual. 



Cartilage is divided into three classes, (1) hyaline, 

 (2) fibre-cartilage, and (3) elastic. The hyaline carti- 

 (150) 



