1. Chapter 9, part 1
Articulations

2. Learning Objectives
Contrast the major categories of joints, and explain the relationship between structure and function for each.
Describe the structure of a synovial joint.
Describe the dynamic movements of the skeleton.
List the types of synovial joint, and discuss the relationship of structure to function in each.

3. Learning Objectives
Describe the structure and function of the vertebrae, shoulder, elbow, hip and knee joints.
Describe the relationship between joint strength and mobility.
Describe the effects of aging on the joints.

4. SECTION 9-1 A Classification of Joints

5. Articulations Articulations Where two bones interconnect
Immovable joints
Synarthroses, or bony
Slightly moveable joints
Amphiarthroses, or fibrous / cartilagenous
Freely moveable joints
Diarthroses, or synovial

6. Synarthroses (immovable joints)
Four major types
Suture = skull bones bound together by dense connective tissue
Gomphosis = teeth bound to bony sockets by periodontal ligaments
Synchondrosis = two bones bound by rigid cartilaginous bridge
Syntosis = two bones completely fused

7. Amphiarthroses (slightly movable joints)
Two major types
Syndesmosis = bones connected by a ligament
Symphysis = bone separated by fibrocartilage

8. Diarthroses (freely movable joints)
Bony surfaces enclosed within articular capsule
Bony surfaces covered by articular cartilage
Bony surfaces lubricated by synovial fluid
Structures include
Menisci
Fat pads
Accessory ligaments
Bursae

9. Figure 9.1 The Structure of a Synovial Joint

10. SECTION 9-2 Articular Form and Function

11. Dynamic motion Dynamic motion Linear motion Angular motion Rotation
Joints classified based on type of motion permitted
Monaxial
Biaxial
Triaxial

12. Figure 9.2 A Simple Model of Articular Motion

13. Types of movement Gliding motion Two surfaces slide past one another
Angular motion
Flexion, extension, hyperextension
Abduction, adduction
Circumduction

14. Figure 9.3 Angular Movements
PLAY
Animation: Flexion, Extension, Hyperextension
Figure 9.3

15. Rotational movement Left or right
Medial (internal) or lateral (external)
Pronation or supination in the bones of the forearm only

16. Figure 9.4 Rotational Movements
Figure 9.4a,b

17. Figure 9.4 Rotational Movements
Figure 9.4c

18. Special movement Movements of the foot Inversion and eversion
Plantar flexion and dorsiflexion
Movements of the thumb
Opposition

19. Other movements Protraction moves a structure anteriorly
Retraction moves a structure posteriorly
Elevation moves a structure superiorly
Depression moves a structure inferiorly
Lateral flexion bends the vertebrae to one side

20. Figure 9.5 Special Movements

21. Structural classification of joints
Gliding joints permit movement in a single plane
Hinge joints are monaxial joints permitting angular motion in one plane
Pivot joints are monaxial joints that permit rotation
Ellipsoid joints are biaxial joints that pit one bone in an oval depression of another
Saddle joints are biaxial joints with one concave and one convex bone face
Ball-and-socket joints are triaxial joints that permit rotation and other movements

22. Figure 9.6 A Functional Classification of Synovial Joints

23. Figure 9.6 A Functional Classification of Synovial Joints
PLAY
Animation: Joint Motion
Figure 9.6