V. 



THE JOINTS. 

 A. The Kinds of Joints. 



Materials. The human skeleton. The student's body. 



Study carefully the human skeleton and identify the 

 four kinds of joints. 



a. A ball and socket joint, e.g. the hip-joint. 



1. What are all the possible movements ? 



2. What is the shape of the different parts of the joint ? 



3. Find other joints of this kind. 



b. A hinge joint, e.g. the knee-joint. 



1. How many movements has it? 



2. What is the shape of the different parts of the joint ? 



3. Find other hinge joints. 



c. A pivot joint, e.g. between the first and second cer- 

 vical vertebrae. 



1. What is the motion ? 



2. How is the joint formed? 



3. Can you find other pivot joints ? 



d. A gliding joint, e.g. between the bones of the wrist, 

 the carpal bones. 



1. What is their motion ? 



2. Find other joints of this kind. 



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