92 ELEMENTS OF MAMMALIAN ANATOMY. 



secretes the white glairy synovia for lubricating the joint. 

 The synovial fluid and membrane may be demonstrated 

 by cutting open a fresh joint obtained from the butcher- 

 shop (Fig. 4). 



All other freely movable joints are similar in structure 

 to the knee-joint, but have no menisci and fewer liga- 

 ments. The shoulder-joint has only two or three liga- 

 ments, the most important of which is the capsular. The 

 elbow- joint has four ligaments and the hip- joint only two. 

 In the ankle-joint there are eight ligaments in addition 

 to the capsular. 



These ligaments which bind the joints consist of white 

 fibrous connective tissue which under the microscope is 

 seen to be composed of parallel and interlacing fibers. 

 They are very tough and have but little elasticity, so 

 that the joints are seldom dislocated (Fig. n). 



PRACTICAL QUESTIONS AND SUGGESTIONS. 



1. Give three examples of each of the three general classes of joints. 



2. Explain difference in anatomy of the three classes of joints. 



3. Without aid of the microscope can you detect any differences 

 between a ligament and a tendon? 



4. By removing the capsular ligament describe the ligaments that 

 can be displayed on the lateral and caudal aspects of the knee-joint. 



5. After bringing to view by dissection as many ligaments as possible 

 on inner aspect of knee-joint, draw and label all parts. 



6. Draw the menisci. 



7. By careful dissection note the ligaments present in the hip-joint. 



8. How many ligaments can you find in the shoulder-joint? 



9. In what joints is synovia present? 



10. Cut a very thin slice of articular cartilage about a millimeter square, 

 mount in dilute acetic acid, and make drawing as seen under the micro- 

 scope. 



