1. Joints P A R T B

2. Plane Joint Plane joints Flat articular surfaces Slipping or gliding Only nonaxial joints Figure 8.7a

3. Types of Synovial Joints Hinge joints Cylinder of one bone fits into a trough on another Uniaxial Flexion and extension only Examples: elbow and interphalangeal joints

4. Hinge Joints Figure 8.7b

5. Pivot Joints Rounded end of one bone fits into a ring of bone on other bone Uniaxial Rotation is the only movement Examples: joint between the axis and the dens, and the proximal radioulnar joint

6. Pivot Joints Figure 8.7c

7. Condyloid or Ellipsoidal Joints Oval surface of one bone fits into a depression in another Both surfaces are oval Biaxial joints permit all angular motions Examples: radiocarpal (wrist) joints, and metacarpophalangeal (knuckle) joints

8. Condyloid or Ellipsoidal Joints Figure 8.7d

9. Saddle Joints Similar to condyloid joints but allow greater movement Each articular surface has both a concave and a convex surface Example: carpometacarpal joint of the thumb

10. Saddle Joints Figure 8.7e

11. Ball-and-Socket Joints Round head of one bone articulates with a socket of another Multiaxial joints Most freely movable joints Examples: shoulder and hip joints

12. Ball-and-Socket Joints Figure 8.7f

13. Synovial Joints: Knee Most complex joint of the body Allows flexion, extension, and some rotation Three joints in one surrounded by a single joint cavity Femoropatellar joint Lateral and medial tibiofemoral joints

14. Synovial Joints: Knee Ligaments and Tendons – Anterior View Tendon of the quadriceps femoris muscle Lateral and medial patellar retinacula Fibular (lateral) and tibial (medial) collateral ligaments Patellar ligament Figure 8.8c

15. Synovial Joints: Knee – Other Supporting Structures Anterior cruciate ligament Posterior cruciate ligament Medial meniscus (semilunar cartilage) Lateral meniscus

16. Synovial Joints: Knee – Other Supporting Structures Figure 8.8b

17. Synovial Joints: Knee – Posterior Superficial View Adductor magnus tendon Articular capsule Oblique popliteal ligament Arcuate popliteal ligament Semimembranosus tendon Figure 8.8e

18. Synovial Joints: Elbow Hinge joint that allows flexion and extension only Radius and ulna articulate with the humerus

19. Synovial Joints: Elbow Figure 8.10a

20. Synovial Joints: Elbow Figure 8.10b Annular ligament Ulnar collateral ligament Radial collateral ligament

21. Synovial Joints: Elbow Figure 8.10d

22. Synovial Joints: Shoulder (Glenohumeral) Ball-and-socket joint Less stable, but more movement Head of humerus articulates with the glenoid fossa (glenoid cavity) of the scapula

23. Synovial Joints: Shoulder Stability Stable due to: Four ligaments – coracohumeral, and three glenohumeral Biceps tendon, which travels through the intertubercular groove and secures the humerus to the glenoid cavity Rotator cuff muscles (four tendons) that encircle the shoulder joint

24. Synovial Joints: Shoulder Stability Figure 8.11a

25. Synovial Joints: Shoulder Stability Figure 8.11b

26. Synovial Joints: Hip (Coxal) Joint Ball-and-socket joint Head of the femur articulates with the acetabulum Less motion than shoulder due to More ligaments Deeper socket

27. Synovial Joints: Hip Stability Acetabular labrum Iliofemoral ligament Pubofemoral ligament Ischiofemoral ligament Ligamentum teres Figure 8.12a

28. Synovial Joints: Hip Stability Figure 8.12c, d

29. Temporomandibular Joint (TMJ) Mandibular condyle meets with mandibular fossa of the temporal bone Two types of movement Hinge – depression and elevation of mandible Side to side – (lateral excursion) grinding of teeth

30. Temporomandibular Joint Figure 8.13a, b

31. Sprains The ligaments reinforcing a joint are stretched or torn Partially torn ligaments slowly repair themselves Completely torn ligaments require prompt surgical repair

32. Dislocations Occur when bones are forced out of alignment Usually accompanied by sprains, inflammation, and joint immobilization Caused by serious falls Common sports injuries

33. Arthritis Inflammatory or degenerative disease that damages the joints Most widespread crippling disease in the U.S. Symptoms – pain, stiffness, and swelling of a joint Acute forms are caused by bacteria Chronic forms include osteoarthritis, rheumatoid arthritis, and gouty arthritis

34. Osteoarthritis (OA) Most common chronic arthritis; often called “wear- and-tear” arthritis Affects women more than men 85% of all Americans develop OA More prevalent in the aged, and is probably related to the normal aging process

35. Osteoarthritis: Course As one ages, cartilage is destroyed more quickly than it is replaced The exposed bone ends thicken, enlarge, form bone spurs, and restrict movement Joints most affected are the spine, fingers, knuckles, knees, and hips

36. Rheumatoid Arthritis (RA) Autoimmune disease of unknown cause Usually arises between the ages of 40 to 50 Signs and symptoms include joint tenderness, anemia, osteoporosis, muscle atrophy, and cardiovascular problems The course of RA is marked with flare-ups and remissions

37. Rheumatoid Arthritis: Course RA begins with synovitis of the affected joint Inflammatory chemicals are released Inflammation occurs

38. Rheumatoid Arthritis: Course Synovial membrane thickens Articular cartilage disappears Bones fuse The end result, ankylosis, produces bent, deformed fingers

39. Gouty Arthritis Deposition of uric acid crystals in joints leads to inflammation Affects the joint at the base of the great toe In untreated gouty arthritis, the bone ends fuse and immobilize the joint