72 LABORATORY EXERCISES. 



hand until the palm of the hand rests on 

 the table. 



a. Which of the bones of the forearm has 



crossed the other? 



b. Note on the articulated skeleton what 



two bones form this pivot- joint at 

 the elbow. 



2. Study the two top vertebrae of the spinal 

 column; move the vertebrae on each 

 other. Describe the provisions that en- 

 able a person to turn his head from side 

 to side. 

 D. Gliding joints. 



1. Count on the articulated skeleton the bones 



forming the wrist. 



2. How many form the ankle? 



3. Which bones are the larger, those of wrist 



or ankle? What advantage is gained in 

 each case? 



4. Move your right wrist and right ankle in as 



many directions as you can. At which 

 joint is the greater range of movement 

 possible ? 



5. Move your lower jaw in as many directions 



as you can. 



a. Between what bones does this move- 



ment take place? 



b. To which classes does this joint, there- 



fore, belong? 



6. Study the joints between the vertebras; 



show how the vertebras, move on each 



