JOINTS 369 



the ligaments half in two to show the cavity of the joint. Notice the 

 smooth and shining appearance of the synovia! membrane which lines 

 the joint and its slight amount of synovial fluid. Bend the joint back 

 and forth to show how the surfaces of the bone fit into each other. 

 Sketch a joint. 



163. Notice some of the inflexible joints. In an animal's skull notice 

 that the joints are dovetailed together with but little cartilage between. 

 Notice the tough pads between the vertebrae, and how they permit the 

 spine to bend slightly. Notice that the ribs are united to the sternum 

 by flexible cartilage. 



164. To show that muscles and cords act as ligaments, clench the 

 fist tightly. Notice that the cords upon the back of the hands tighten, 

 as well as those which shut the hand. 



REVIEW TOPICS 



1. Describe and locate the inflexible joints with bony 



union ; with union by cartilage ; with union by pads 

 of fibrous tissue; and with union by being dove- 

 tailed together. 



2. Describe and locate hinge joints ; the ball and socket 



joints ; and the pivot joints. 



3. Describe the structure of joints, their ligaments, syno- 



vial membrane, and fluid. 



4. Show how muscles aid the action of the ligaments. 



5. Show how long-continued pressure affects the joints, 



as in the great toe. 



6. Show how the position of the body may produce curva- 



ture of the spine. 



7. Describe the nature and treatment of a sprain, and of 



a dislocation. 



8. Show how joints may become inflamed. 



9. Describe a white swelling. 

 10. Describe a bunion. 



OV. PHYSIOL. 24 



