1. Joints (a.k.a. Articulations)

2. I. Introduction A.Joint 1. articulation 1. Also called an articulation 2. Defined: A joint is a point of contact between bones, cartilage and bones, or teeth and bone

3. I. Introduction B. Function 1. 1. they hold the skeletal bones together 2. 2. Allows the rigid skeleton some flexibility so that gross movements can occur

4. C. Relationship between Joints and Movements 1. The closer the fit between bones at a joint, the stronger the joint. 2. Strong joints exhibit restricted movements. 3. The greater the distance between articulating bones the greater range of movements

5. II. Classification A. Based on either 1. S 1. S tructure based on the nature of the material comprising them 2. Function based on degree of movement they allow

6. II. Classification B. Functional Classifications 1. 1. Synarthroses arthrose=joint, syn=together Immovable jointsImmovable joints Examples: suturesExamples: sutures

7. Synarthroses

8. II. Classification C. Functional Classifications 2. 2. Amphiarthroses arthrose=joint, amphi=both Slightly movable joints Between tibia and fibula

9. Amphiarthroses

10. II. Classification C. Functional Classifications 3. 3. Diarthroses arthrose=joint, dia=apart a. freely movable joint b. example: knee joint

11. II. Classification b. no joint cavity C. Structural classifications 1. 1. Fibrous Joints a. joints held together by fibrous connective tissue

12. SUTURES Bones are held together by a thin layer of dense fibrous tissue and also by interlocking projections of the bones. Found only in the skull

13. GOMPHOSES a peg-in-socket fibrous joint

14. Bones are held together by a cord or sheet of dense fibrous connective tissue SYNDESMOSES

15. II. Classification B. Structural Classifications 2. 2. Cartilaginous Joints a.held together by cartilaginous tissue b. no joint cavity

16. Synchondroses immovable only hyaline cartilage

17. SYMPHYSIS VERY limited movement Hyaline and fibrous cartilage

18. B. Structural Classifications 3. 3. Synovial joints a.held together by a synovial capsule b. Have a joint cavity c. Includes most joints

20. Gliding Joints Plane (= gliding). Opposite bone surfaces are flat or slightly curved. Only sliding motion in all directions are allowed.

21. Hinge Joints Convex surface of one bone fits smoothly into concave surface of the second bone.

22. Pivot Joints A rounded, pointed or conical surface of one bone is inserted into a ring made partly of another bone and partly of a ligament. only movement allowed is the rotation of one bone around its own axis

23. Ellipsoidal (= condyloid) Joints Oval-shaped surface fits into an oval-shaped cavity

24. Saddle Joints First bone's articular surface is concave in one direction and convex in the other while the second bone is just the opposite.

25. Ball and Socket Joints head fits into a cup- shaped depress ion most freely moving of all joints

27. V. Joints (a.k.a. Articulations) C.Types of Movement in Synovial Joints 1.Gliding slight movementslight movement example: vertebrae 2.Rotation Movement around the long axis of limb Shoulder joint

28. V. Joints (a.k.a. Articulations) C.Types of Movement in Synovial Joints 3.Angular a. flexion decreasing angle b. extensio n Increasing angle

30. C. Types of Movement in Synovial Joints C.Angular a. hyperextension extension beyond anatomical position b. circumduction limb movement with limb describing a cone

31. V. Joints (a.k.a. Articulations) C.Types of Movement in Synovial Joints 3.Angular abduction d. abduction movement away from midline e. adduction e. adduction toward midline

32. C.Types of Movement in Synovial Joints 4.Rotation turns right to left

33. 4. Rotation a. a. pronation turns wrist so palm is facing dorsally b. supination b. supination palm turned anteriorly C. Types of Movement in Synovial Joints

34. 5. Special Cases a. a. plantar flexion and dorsiflexion b. dorsiflexion C. Types of Movement in Synovial Joints