1. Joint Structure

2. Classification of Joints
Fibrous (synarthroses): lacks a joint cavity and the articulating bones are held very closely together by fibrous connective tissue; they permit little or no movement
sutures
syndesmoses
gomphoses

3. Sutures
found between the bones of the skull and are united by a thin layer of dense fibrous connective tissue

4. Syndesmoses
fibrous connective tissue forms an interosseous membrane or ligament (distal articulation of the tibia and fibula, shafts of radius and ulna)

5. Gomphoses
cone-shaped peg fits into a socket (teeth)

6. Classification of Joints
Cartilaginous (amphiarthroses): lacks a joint cavity and the articulating bones are tightly connected by cartilage
synchrondrosis
symphyses

7. Synchrondrosis
connecting material is hyaline cartilage (epiphyseal plate)

8. Symphyses
connecting material is a broad, flat disc of fibrocartilage (pubic symphysis; bodies of vertebrae)

9. Classification of Joints
Synovial (diarthroses): joint cavity (space between the articulating bones) is present; freely movable.
Gliding
Hinge
Pivot
Ellipsoidal
Saddle
Ball and socket

10. Synovial Joints are freely movable

11. Gliding
side-to-side and back-and-forth movements (biaxial); articulating surfaces are usually flat (intercarpal, intertarsal, sternum and clavicle)

13. Synovial Joints

14. Hinge
motions are flexion/extension (monoaxial); convex surface of one bone fits into the concave surface of another (elbow, knee)

16. Synovial Joints

17. Pivot
rotational movement (monoaxial); rounded, pointed, or concave surface fits into a ring formed partly by bone and partly by a ligament (atlas and axis)

19. Synovial Joints

20. Ellipsoidal
side-to-side and back-and-forth movements (biaxial); oval shaped condyle fits into an elliptical cavity (wrist)

22. Synovial Joints

23. Saddle
side-to-side and back-and-forth movements (biaxial); articular surfaces concave in one direction and convex in opposite direction (CMC of thumb)

25. Synovial Joints

26. Ball and socket
movement in 3 planes (triaxial); ball like surface fits into a cuplike depression (shoulder and hip)

28. Synovial Joints

29. Components of Synovial Joints
articular cartilage: covers surfaces of articulating bones but does not bind them together
articular capsule: surrounds the articular surfaces and encloses the joint cavity
outer layer (fibrous capsule): attached to the periosteum of articulating bones at a variable distance from the edge of the articulating cartilage
inner layer (synovial membrane): secretes synovial fluid which lubricates the joint and provides nourishment for the articular cartilage

30. Components of Synovial Joints
joint (synovial) cavity: enclosed space that surrounds the 2 articulating surfaces; contains the slippery lubricating fluid called synovial fluid
ligaments: thickened collagenous bands connecting bone to bone
extracapsular ligaments are outside of the articular capsule (MCL, LCL)
intracapsular ligaments directly attach the 2 articulating surfaces (ACL, PCL)

31. Components of Synovial Joints
articular discs (menisci): pads of fibrocartilage that lie between the articular surfaces of the bones; help maintain the stability of a joint and direct the flow of synovial fluid to areas of greatest friction; not all synovial joints have them

32. Components of Synovial Joints
bursae: saclike structures that contain synovial fluid to help reduce friction between:
skin and bone
tendons and bones
muscles and bones
ligaments and bones