1. PowerPoint ® Lecture Slides prepared by Leslie Hendon, University of Alabama, Birmingham HUMAN ANATOMY fifth edition MARIEB | MALLATT | WILHELM 9 Copyright © 2008 Pearson Education, Inc., publishing as Benjamin Cummings Joints PART 1

2. Copyright © 2008 Pearson Education, Inc., publishing as Benjamin Cummings Joints  Rigid elements of the skeleton meet at joints or articulations  Greek root “arthro” means joint  Articulations can be  Bone to bone  Bone to cartilage  Teeth in bony sockets  Structure of joints  Enables resistance to crushing, tearing, and other forces

3. Copyright © 2008 Pearson Education, Inc., publishing as Benjamin Cummings Classifications of Joints  Joints can be classified by function or structure  Functional classification – based on amount of movement  Synarthroses – immovable; common in axial skeleton  Amphiarthroses – slightly movable; common in axial skeleton  Diarthroses – freely movable; common in appendicular skeleton (all synovial joints)

4. Copyright © 2008 Pearson Education, Inc., publishing as Benjamin Cummings Classifications of Joints  Structural classification based on  Material that binds bones together  Presence or absence of a joint cavity  Structural classifications include  Fibrous  Cartilaginous  Synovial

5. Copyright © 2008 Pearson Education, Inc., publishing as Benjamin Cummings Fibrous Joints  Bones are connected by fibrous connective tissue  Do not have a joint cavity  Most are immovable or slightly movable  Types  Sutures  Syndesmoses  Gomphoses

6. Copyright © 2008 Pearson Education, Inc., publishing as Benjamin Cummings Sutures  Bones are tightly bound by a minimal amount of fibrous tissue  Only occur between the bones of the skull  Allow bone growth so the skull can expand with brain during childhood  Fibrous tissue ossifies in middle age  Synostoses – closed sutures

7. Copyright © 2008 Pearson Education, Inc., publishing as Benjamin Cummings Syndesmoses  Bones are connected exclusively by ligaments  Amount of movement depends on length of fibers  Tibiofibular joint –immovable synarthrosis  Interosseous membrane between radius and ulna  Freely movable diarthrosis

8. Copyright © 2008 Pearson Education, Inc., publishing as Benjamin Cummings Fibrous Joints Figure 9.1a, b

9. Copyright © 2008 Pearson Education, Inc., publishing as Benjamin Cummings Gomphoses  Tooth in a socket  Connecting ligament – the periodontal ligament Figure 9.1c

10. Copyright © 2008 Pearson Education, Inc., publishing as Benjamin Cummings Cartilaginous Joints  Bones are united by cartilage  Lack a joint cavity  Two types  Synchondroses  Symphyses

11. Copyright © 2008 Pearson Education, Inc., publishing as Benjamin Cummings Synchondroses  Hyaline cartilage unites bones  Epiphyseal plates Figure 9.2a

12. Copyright © 2008 Pearson Education, Inc., publishing as Benjamin Cummings Synchondroses  Joint between first rib and manubrium Figure 9.2b

13. Copyright © 2008 Pearson Education, Inc., publishing as Benjamin Cummings Symphyses  Fibrocartilage unites bones – resists tension and compression  Slightly movable joints that provide strength with flexibility  Intervertebral discs  Pubic symphysis

14. Copyright © 2008 Pearson Education, Inc., publishing as Benjamin Cummings Symphyses  Hyaline cartilage – also present as articular cartilage Figure 9.2c

15. Copyright © 2008 Pearson Education, Inc., publishing as Benjamin Cummings Synovial Joints  Most movable type of joint  All are diarthroses  Each contains a fluid-filled joint cavity

16. Copyright © 2008 Pearson Education, Inc., publishing as Benjamin Cummings General Structure of Synovial Joints  Articular cartilage  Ends of opposing bones are covered with hyaline cartilage  Absorbs compression  Joint cavity (synovial cavity)  Unique to synovial joints  Cavity is a potential space that holds a small amount of synovial fluid

17. Copyright © 2008 Pearson Education, Inc., publishing as Benjamin Cummings General Structure of Synovial Joints  Articular capsule – joint cavity is enclosed in a two-layered capsule  Fibrous capsule – dense irregular connective tissue, which strengthens joint  Synovial membrane – loose connective tissue  Lines joint capsule and covers internal joint surfaces  Functions to make synovial fluid

18. Copyright © 2008 Pearson Education, Inc., publishing as Benjamin Cummings General Structure of Synovial Joints  Synovial fluid  A viscous fluid similar to raw egg white  A filtrate of blood with added lubricants  Arises from capillaries in synovial membrane  Contains glycoprotein molecules secreted by fibroblasts  Synovial joints are subject to compressive forces. This acts like a “sponge”. When the pressure releases, fluid is absorbed into the joint, then when compressed again, it is squeezed out. This mechanism is called “weeping lubrication”

19. Copyright © 2008 Pearson Education, Inc., publishing as Benjamin Cummings General Structure of Synovial Joints  Reinforcing ligaments  Often are thickened parts of the fibrous capsule  Sometimes are extracapsular ligaments – located outside the capsule  Sometimes are intracapsular ligaments – located internal to the capsule

20. Copyright © 2008 Pearson Education, Inc., publishing as Benjamin Cummings A Typical Synovial Joint Figure 9.3a

21. Copyright © 2008 Pearson Education, Inc., publishing as Benjamin Cummings General Structure of Synovial Joints  Richly supplied with sensory nerves  Detect pain  Most monitor how much the capsule is being stretched

22. Copyright © 2008 Pearson Education, Inc., publishing as Benjamin Cummings General Structure of Synovial Joints  Have a rich blood supply  Most supply the synovial membrane  Extensive capillary beds produce basis of synovial fluid  Branches of several major nerves and blood vessels

23. Copyright © 2008 Pearson Education, Inc., publishing as Benjamin Cummings Synovial Joints with Articular Discs  Some synovial joints contain an articular disc  Occur in the temporomandibular joint and at the knee joint  Occur in joints whose articulating bones have somewhat different shapes Figure 9.3c

24. Copyright © 2008 Pearson Education, Inc., publishing as Benjamin Cummings Summary of Joint Classes Table 9.1 (1 of 2)

25. Copyright © 2008 Pearson Education, Inc., publishing as Benjamin Cummings How Synovial Joints Function  Synovial joints – lubricating devices  Friction could overheat and destroy joint tissue  Are subjected to compressive forces  Fluid is squeezed out as opposing cartilages touch  Cartilages ride on the slippery film

26. Copyright © 2008 Pearson Education, Inc., publishing as Benjamin Cummings Bursae and Tendon Sheaths  Bursae and tendon sheaths are not synovial joints  Closed bags of lubricant  Reduce friction between body elements  Bursa – a flattened fibrous sac lined by a synovial membrane  Tendon sheath – an elongated bursa that wraps around a tendon, it occurs in the carpal tunnel which is subject to overuse and causing Carpal Tunnel Syndrome

27. Copyright © 2008 Pearson Education, Inc., publishing as Benjamin Cummings Bursae and Tendon Sheaths Figure 9.4a, b

28. Copyright © 2008 Pearson Education, Inc., publishing as Benjamin Cummings Factors Influencing Joint Stabililty  Articular surfaces – seldom play a major role in joint stability  The elbow, the knee and the hip do provide stability  Ligaments – the more ligaments in a joint, the stronger it is  Muscle tone – the most important factor in joint stability  Keeps tension on muscle tendons

29. Copyright © 2008 Pearson Education, Inc., publishing as Benjamin Cummings Movements Allowed by Synovial Joints  Three basic types of movement  Gliding – one bone across the surface of another  Angular movement – movements change the angle between bones  Rotation – movement around a bone's long axis

30. Copyright © 2008 Pearson Education, Inc., publishing as Benjamin Cummings Gliding Joints  Flat surfaces of two bones slip across each other  Gliding occurs between  Carpals  Articular processes of vertebrae  Tarsals Figure 9.5a

31. Copyright © 2008 Pearson Education, Inc., publishing as Benjamin Cummings Angular Movements  Increase or decrease angle between bones  Movements involve  Flexion and extension  Abduction and adduction  Circumduction

32. Copyright © 2008 Pearson Education, Inc., publishing as Benjamin Cummings Angular Movements Figure 9.5b

33. Copyright © 2008 Pearson Education, Inc., publishing as Benjamin Cummings Angular Movements Figure 9.5c

34. Copyright © 2008 Pearson Education, Inc., publishing as Benjamin Cummings Angular Movements Figure 9.5d

35. Copyright © 2008 Pearson Education, Inc., publishing as Benjamin Cummings Angular Movements Figure 9.5e PLAY Movement of the pectoral girdle (a)

36. Copyright © 2008 Pearson Education, Inc., publishing as Benjamin Cummings Rotation  Involves turning movement of a bone around its long axis  The only movement allowed between atlas and axis vertebrae  Occurs at the hip and shoulder joints

37. Copyright © 2008 Pearson Education, Inc., publishing as Benjamin Cummings Special Movements  Supination – forearm rotates laterally, palm faces anteriorly  Pronation – forearm rotates medially, palm faces posteriorly

38. Copyright © 2008 Pearson Education, Inc., publishing as Benjamin Cummings Special Movements Figure 9.6a

39. Copyright © 2008 Pearson Education, Inc., publishing as Benjamin Cummings Special Movements  Dorsiflexion – lifting the foot so the superior surface approaches the shin  Plantar flexion – depressing the foot, pointing the toes

40. Copyright © 2008 Pearson Education, Inc., publishing as Benjamin Cummings Special Movements  Inversion – turning the sole medially  Eversion – turning the sole laterally Figure 9.6c PLAY Movement of the ankle and foot (a)

41. Copyright © 2008 Pearson Education, Inc., publishing as Benjamin Cummings Special Movements  Protraction – nonangular movement of jutting out the jaw  Retraction – opposite movement to protraction Figure 9.6d

42. Copyright © 2008 Pearson Education, Inc., publishing as Benjamin Cummings Special Movements  Elevation – lifting a body superiorly  Depression – moving the elevated part inferiorly Figure 9.6e

43. Copyright © 2008 Pearson Education, Inc., publishing as Benjamin Cummings Special Movements  Opposition – movement of the thumb to touch the tips of other fingers Figure 9.6f

44. Copyright © 2008 Pearson Education, Inc., publishing as Benjamin Cummings Synovial Joints Classified by Shape  Plane joint  Articular surfaces are flat planes  Short gliding movements are allowed  Intertarsal and intercarpal joints  Movements are nonaxial  Gliding does not involve rotation around any axis

45. Copyright © 2008 Pearson Education, Inc., publishing as Benjamin Cummings Synovial Joints Classified by Shape  Hinge joints  Cylindrical end of one bone fits into a trough on another bone  Angular movement is allowed in one plane  Elbow, ankle, and joints between phalanges  Movement is uniaxial – allows movement around one axis only

46. Copyright © 2008 Pearson Education, Inc., publishing as Benjamin Cummings Hinge Joint Figure 9.7b

47. Copyright © 2008 Pearson Education, Inc., publishing as Benjamin Cummings Pivot Joint Figure 9.7c

48. Copyright © 2008 Pearson Education, Inc., publishing as Benjamin Cummings Synovial Joints Classified by Shape  Condyloid joints  Allow moving bone to travel  Side to side – abduction-adduction  Back and forth – flexion-extension  Classified as biaxial – movement occurs around two axes

49. Copyright © 2008 Pearson Education, Inc., publishing as Benjamin Cummings Condyloid Joint Figure 9.7d

50. Copyright © 2008 Pearson Education, Inc., publishing as Benjamin Cummings Synovial Joints Classified by Shape  Saddle joints  Each articular surface has concave and convex surfaces  Classified as biaxial joints

51. Copyright © 2008 Pearson Education, Inc., publishing as Benjamin Cummings Synovial Joints Classified by Shape Figure 9.7e

52. Copyright © 2008 Pearson Education, Inc., publishing as Benjamin Cummings Synovial Joints Classified by Shape  Pivot joints  Classified as uniaxial – rotating bone only turns around its long axis  Examples  Proximal radioulnar joint  Joint between atlas and axis

53. Copyright © 2008 Pearson Education, Inc., publishing as Benjamin Cummings Pivot Joint Figure 9.7c

54. Copyright © 2008 Pearson Education, Inc., publishing as Benjamin Cummings Synovial Joints Classified by Shape  Condyloid joints  Allow moving bone to travel  Side to side – abduction-adduction  Back and forth – flexion-extension  Classified as biaxial – movement occurs around two axes

55. Copyright © 2008 Pearson Education, Inc., publishing as Benjamin Cummings Condyloid Joint Figure 9.7d

56. Copyright © 2008 Pearson Education, Inc., publishing as Benjamin Cummings Synovial Joints Classified by Shape  Saddle joints  Each articular surface has concave and convex surfaces  Classified as biaxial joints

57. Copyright © 2008 Pearson Education, Inc., publishing as Benjamin Cummings Synovial Joints Classified by Shape Figure 9.7e

58. Copyright © 2008 Pearson Education, Inc., publishing as Benjamin Cummings Synovial Joints Classified by Shape  Ball-and-socket joints  Spherical head of one bone fits into round socket of another  Classified as multiaxial – allow movement in all axes  Shoulder and hip joints

59. Copyright © 2008 Pearson Education, Inc., publishing as Benjamin Cummings Ball-and-Socket Joint Figure 9.7f PLAY Movement of the glenohumeral joint (a)

60. Copyright © 2008 Pearson Education, Inc., publishing as Benjamin Cummings Sternoclavicular Joint Figure 9.8a

61. Copyright © 2008 Pearson Education, Inc., publishing as Benjamin Cummings Sternoclavicular Joint Figure 9.8b

62. Copyright © 2008 Pearson Education, Inc., publishing as Benjamin Cummings Selected Synovial Joints  Shoulder (Glenohumeral) joint  The most freely movable joint lacks stability  Articular capsule is thin and loose  Muscle tendons contribute to joint stability

63. Copyright © 2008 Pearson Education, Inc., publishing as Benjamin Cummings Glenohumeral Joint Figure 9.8a

64. Copyright © 2008 Pearson Education, Inc., publishing as Benjamin Cummings Glenohumeral Joint  The rotator cuff is made up of four muscles and their associated tendons  Subscapularis  Supraspinatus  Infraspinatus  Teres minor  Rotator cuff injuries are common shoulder injuries

65. Copyright © 2008 Pearson Education, Inc., publishing as Benjamin Cummings The shoulder joint Figure 9.8b, c

66. Copyright © 2008 Pearson Education, Inc., publishing as Benjamin Cummings The Shoulder Joint Figure 9.8d, e

67. Copyright © 2008 Pearson Education, Inc., publishing as Benjamin Cummings Selected Synovial Joints  Elbow joint  Allows flexion and extension  The humerus’ articulation with the trochlear notch of the ulna forms the hinge  Tendons of biceps and triceps brachii provide stability

68. Copyright © 2008 Pearson Education, Inc., publishing as Benjamin Cummings Elbow Joint Figure 9.9a, b

69. Copyright © 2008 Pearson Education, Inc., publishing as Benjamin Cummings Elbow Joint Figure 9.9c, d

70. Copyright © 2008 Pearson Education, Inc., publishing as Benjamin Cummings Wrist Joint  Stabilized by numerous ligaments  Composed of radiocarpal and intercarpal joint  Radiocarpal joint – joint between the radius and proximal carpals (the scaphoid and lunate)  Allows for flexion, extension, adduction, abduction, and circumduction  Intercarpal joint – joint between the proximal and distal rows or carpals  Allows for gliding movement

71. Copyright © 2008 Pearson Education, Inc., publishing as Benjamin Cummings Wrist Joint Figure 9.10a

72. Copyright © 2008 Pearson Education, Inc., publishing as Benjamin Cummings Wrist Joint Figure 9.10b

73. Copyright © 2008 Pearson Education, Inc., publishing as Benjamin Cummings Wrist Joint Figure 9.10c

74. Copyright © 2008 Pearson Education, Inc., publishing as Benjamin Cummings Selected Synovial Joints  Hip joint  A ball-and-socket structure  Movements occur in all axes  Limited by ligaments and acetabulum  Head of femur articulates with acetabulum  Stability comes chiefly from acetabulum and capsular ligaments  Muscle tendons contribute somewhat to stability

75. Copyright © 2008 Pearson Education, Inc., publishing as Benjamin Cummings Frontal Section and Anterior View of the Hip Joint Figure 9.11a, b

76. Copyright © 2008 Pearson Education, Inc., publishing as Benjamin Cummings Posterior View of the Hip Joint Figure 9.11c, d

77. Copyright © 2008 Pearson Education, Inc., publishing as Benjamin Cummings Selected Synovial Joints  Knee joint  The largest and most complex joint  Primarily acts as a hinge joint  Has some capacity for rotation when leg is flexed  Structurally considered compound and bicondyloid  Two fibrocartilage menisci occur within the joint cavity

78. Copyright © 2008 Pearson Education, Inc., publishing as Benjamin Cummings Sagittal Section and Superior View of Knee Joint Figure 9.12a

79. Copyright © 2008 Pearson Education, Inc., publishing as Benjamin Cummings Sagittal Section and Superior View of Knee Joint Figure 9.12b

80. Copyright © 2008 Pearson Education, Inc., publishing as Benjamin Cummings Knee Joint  Capsule of knee joint  Covers posterior and lateral aspects of the knee  Covers tibial and femoral condyles  Does not cover the anterior aspect of the knee  Anteriorly covered by three ligaments  Patellar, medial, and lateral retinacula

81. Copyright © 2008 Pearson Education, Inc., publishing as Benjamin Cummings Anterior View of Knee Figure 9.12c

82. Copyright © 2008 Pearson Education, Inc., publishing as Benjamin Cummings Knee Joint  Ligaments of the knee joint  Become taut when knee is extended  These extracapsular ligaments are  Fibular and tibial collateral ligament  Oblique popliteal ligament  Arcuate popliteal ligament

83. Copyright © 2008 Pearson Education, Inc., publishing as Benjamin Cummings Posterior View of Knee Joint Figure 9.12d

84. Copyright © 2008 Pearson Education, Inc., publishing as Benjamin Cummings Knee Joint  Intracapsular ligaments  Cruciate ligaments  Cross each other like an “X”  Each cruciate ligament runs from the proximal tibia to the distal femur  Anterior cruciate ligament  Posterior cruciate ligament

85. Copyright © 2008 Pearson Education, Inc., publishing as Benjamin Cummings Anterior View of Flexed Knee Figure 9.12e, f

86. Copyright © 2008 Pearson Education, Inc., publishing as Benjamin Cummings Figure 9.13a Knee Joint  Cruciate ligaments  Prevent undesirable movements at the knee joint

87. Copyright © 2008 Pearson Education, Inc., publishing as Benjamin Cummings Selected Synovial Joint  Ankle Joint  A hinge joint between  United inferior ends of tibia and fibula  The talus of the foot  Allows the movements  Dorsiflexion and plantar flexion only

88. Copyright © 2008 Pearson Education, Inc., publishing as Benjamin Cummings The Ankle Joint  Medially and laterally stabilized by ligaments  Medial (deltoid) ligament  Lateral ligament  Inferior ends of tibia and fibula are joined by ligaments  Anterior and posterior tibiofibular ligaments

89. Copyright © 2008 Pearson Education, Inc., publishing as Benjamin Cummings The Ankle Joint Figure 9.15a

90. Copyright © 2008 Pearson Education, Inc., publishing as Benjamin Cummings Ligaments of the Ankle Joint Figure 9.15b

91. Copyright © 2008 Pearson Education, Inc., publishing as Benjamin Cummings Ligaments of the Ankle Joint Figure 9.15c

92. Copyright © 2008 Pearson Education, Inc., publishing as Benjamin Cummings Ligaments of the Ankle Joint Figure 9.15d

93. Copyright © 2008 Pearson Education, Inc., publishing as Benjamin Cummings Selected Synovial Joints  Temporomandibular joint (TMJ)  Lies anterior to the ear  Head of the mandible articulates with the mandibular fossa  Two surfaces of the articular disc allow two kinds of movement  Hinge-like movement  Superior surface of disc glides anteriorly

94. Copyright © 2008 Pearson Education, Inc., publishing as Benjamin Cummings The Temporomandibular Joint Figure 9.16a, b

95. Copyright © 2008 Pearson Education, Inc., publishing as Benjamin Cummings Selected Synovial Joints  Sternoclavicular Joint  Is a saddle joint  Muscles and ligaments contribute to joint stability  Unique joint shape allows for multiple complex movements  Another example of a saddle joint  Joint between trapezium and metacarpal 1

96. Copyright © 2008 Pearson Education, Inc., publishing as Benjamin Cummings Sternoclavicular Joint Figure 9.17a

97. Copyright © 2008 Pearson Education, Inc., publishing as Benjamin Cummings Sternoclavicular Joint Figure 9.17b

98. Copyright © 2008 Pearson Education, Inc., publishing as Benjamin Cummings Disorders of Joints  Structure of joints makes them prone to traumatic stress  Function of joints makes them subject to friction and wear  Affected by inflammatory and degenerative processes

99. Copyright © 2008 Pearson Education, Inc., publishing as Benjamin Cummings Joint Injuries  Sprains – ligaments of a reinforcing joint are stretched or torn  Dislocation – occurs when the bones of a joint are forced out of alignment  Torn cartilage – common injury to meniscus of knee joint

100. Copyright © 2008 Pearson Education, Inc., publishing as Benjamin Cummings Inflammatory and Degenerative Conditions  Bursitis – inflammation of a bursa do to injury or friction  Tendonitis – inflammation of a tendon sheath

101. Copyright © 2008 Pearson Education, Inc., publishing as Benjamin Cummings Inflammatory and Degenerative Conditions  Arthritis – describes over 100 kinds of joint- damaging diseases  Osteoarthritis – most common type “wear and tear” arthritis  Rheumatoid arthritis – a chronic inflammatory disorder  Gouty arthritis (gout) – uric acid build-up causes pain in joints  Lyme disease – inflammatory disease often resulting in joint pain

102. Copyright © 2008 Pearson Education, Inc., publishing as Benjamin Cummings The Joints Throughout Life  Synovial joints develop from mesenchyme  By week 8 of fetal development, joints resemble adult joints  Outer region of mesenchyme becomes fibrous joint capsule  Inner region becomes the joint cavity

103. Copyright © 2008 Pearson Education, Inc., publishing as Benjamin Cummings The Joints Throughout Life  During youth – injury may tear an epiphysis off a bone shaft  Advancing age – osteoarthritis becomes more common  Exercise – helps maintain joint health