1. Articulations

2. Articulations- points where two or more bones come together to form a joint [ maybe rigid or movable] Classified by Structure or Function Structure- based on material that joins bones together Fibrous – fibrous connective tissue Cartilagenous – hyaline or fibrocartilage Synovial – joint cavity with synovial membrane

3. Synovial Joint Capsule is continuous with periosteum Membrane is 2 layers Has blood vessels & nerves

4. Synovial Fluid Continuously made, circulated – at any time there is 3 ml [ 0.1 oz] in cavity Resembles interstitial fluid, but contains proteoglycans secreted by fibroblasts  making it thick / viscous Functions: lubricate joint distribute nutrients and remove waste products shock absorber defense

5. Accessories of Synovial Joint Cartilage – fibrocartilage [articular discs or meniscus] Fat – articular fat pads Ligaments [ attach bone to bone] Tendons [ attach muscle to bone] Bursae – synovial fluid filled ‘pockets’ mini shock absorbers

6. Function – based on degree of movement Synarthroses – immovable Amphiarthroses – slightly movable Diarthroses – freely moveable

7. Fibrous Articulations Bones are held tightly connected by fibrous connective tissue or cartilage. Joints are rigid and immoveable. Sutures – found only in skull. Bones joined by fibrous connective tissue Syndesmosis – band of fibrous connective tissue, holds bones tightly together distal end of tibia/fibula Gomphosis – peg in socket tooth in alveoli- periodontal ligament

8. Syndesmosis

9. Cartilagenous Articulations Hyaline or fibrous cartilage joins bones; limited motion in response to twisting, compression, stress Synchondrosis – hyaline cartilage joins bones. epiphyseal plate, costal cartilages Symphysis – pad of fibrocartilage separates bones. intervertebral discs, symphysis pubis

10. Synchondrosis Symphysis

11. Synovial Articulations Freely moveable joints. Include a capsule lined with a membrane and contains fluid Range of movement limited by: 1.Structure of bones 2.Strength and tautness of ligaments, tendons, joint capsule 3.Size, arrangement, action of muscles

12. Types of Synovial Articulations Hinge – concave surface on one articulates with convex surface of another. Pivot – conical surface on one articulates with depression on another Condyloid – oval condyle on one articulates with elliptical cavity on another Gliding- flattened or slightly curved articulating surfaces Saddle – concave and convex surface on each articulating bone Ball and Socket – rounded surface on one articulates with cuplike socket on another

13. Pivot saddle Ball & Socket

14. CondyloidGliding Hinge

15. Bursa – fluid filled sacs near diarthrotic joints – between muscles, skin and bones or tendon and bone. Reduce friction and stress associated with movement Tendon Sheaths – modified bursae that surround and lubricate tendons of certain muscles, esp. those that cross wrist and ankle