Introduction to articulations

1. Chapter 9 Articulations

2. What is a joint?

3. Articulations (joints) frequently allow movement between bones. However, not all joints are flexible or moveable.

4. Arthrology is the study of joints

5. Kinesiology is the study of the functional relationship of the skeleton, joints, muscles, and nerves.

6. The structure of a joint greatly determines the range of movement

7. Mobility versus Stability . You cannot have both!

8. There are 3 types of structural joints and there are 3 types of functional articulations . You must know the terms for all of them!

9. Shown is the fractured humerus of a Native American that was not immobilized to allow healing and fusion. It eventually progressed to form a false joint ( pseudoarthrosis ) in the brachium.

10. Brachial pseudoarthosis in an uncooperative homeless alcoholic.

11. Gomphoses are fibrous synarthrotic joints only found in the maxillae and mandible where the root of the tooth is attached to the alveolus

13. Read about gomphoses and orthodontic braces in the clinical view in the text.

15. Sutures are initially fibrous synarthrotic joints that are only found in the skull. They replace the membranous fontanels at about 18 months of age. In early adulthood the fibrous connective tissue is replaced by bone so the skull bones are bone fused to bone (a synostosis ).

16. A syndesmosis also exists between the distal ends of the radius and ulna. It also allows slight movement ( amphiarthrotic ).

17. A syndesmosis exists between the distal ends of the tibia and fibula and is permits slight movement ( amphiarthrotic )

18. Syndesmoses are possible because of the interosseous membrane that holds the bones together, while still allowing slight movement.

19. WHICH OF THE FOLLOWING IS CORRECT ABOUT ORTHODONTIC BRACES? A APPLIED IN THE BUCCAL CAVITY B CAUSE TENSION ON PERIODONTAL LIGAMENTS C ALTER FIBROUS JOINTS D AFFECT SYNARTHROSES E ALL OF THE ABOVE

20. Synchondroses are joined together by hyaline cartilage and, since they are immovable, they are also synarthroses.

21. Synchondroses have hyaline cartilage between the articulating bone segments. One example is epiphyseal growth plates . These growth plates eventually become synostoses.

22. Costal cartilage persists into adulthood and forms sychondroses . In old age these cartilages do occasionally ossify and form synostoses.

23. Symphyses are joined together by fibrocartilage and, since they are slightly moveable, they are also amphiarthroses .

24. The pubic symphysis is an amphiarthrotic cartilaginous joint that can be loosened by hormones produced in pregnancy.

25. Recall that the hormone relaxin loosens the symphysis pubis and the sacroiliac joint during pregnancy to increase the diameter of the true pelvis and the pelvic outlet to facilitate parturition.

26. symphysis Intervertebral joints between the bodies of the vertebrae and their separating intervertebral discs form amphiarthrotic symphyses

27. Close-up view of fibrocartilage

28. Synovial joints are diarthrotic (freely moveable) joints encased by joint capsules that contain joint (synovial) fluid.

29. Diarthrotic synovial joints are the most obvious type of articulation in the body.

30. A synovial joint’s range of motion is limited by the shape of the articulating bones, ligaments, tendons, the joint capsule, and by muscles that span the joint.

31. There is tremendous individual variability in joint motility, most of which is related to body conditioning.

32. Hypermobility of a single joint (“double-jointed”) makes an individual more prone to joint dislocation and damage to the joint and joint capsule.

35. “ Ruby Ring” born SLC, UT 1921-2002 8 th of 9 children Left home at 14 yrs old to be a contortionist

36. Read the clinical view in the text about Marfan Syndrome

37. Synovial joints are enclosed by a fibroelastic joint capsule, which has an outer layer called the fibrous capsule and in inner layer called the synovial membrane..

38. The synovial membrane secretes a viscous oily synovial fluid which lubricates the articular cartilage and which brings nutrients and removes wastes from the chondrocytes

39. The popping sound that occurs when a joint is pulled or stretched is typically caused by gas bubbles that form in the synovial fluid and burst (causing the popping sound) when the pressure in the synovial fluid is decreased.

40. Popping sounds of the back when stretched or pressed can also be caused by rupturing gas bubbles in the synovial fluid or by sudden repositioning of articular surfaces

41. Since articular cartilage is avascular, it heals poorly. In this endoscopic view of the knee, the doctor is drilling holes through the damaged articular cartilage into the bony epiphysis so blood can reach the cartilage to affect repair.

42. Articular cartilage of the knee after holes are drilled into the bony epiphysis so blood can reach the cartilage to promote healing.

43. The repititious compression/relaxation that occurs during exercise is vital to the articular cartilage’s well-being because the accompanying pumping action enhances its nutrition and waste removal from the surrounding synovial fluid.

44. Ligaments , which connect bones to bones across a joint, are composed of dense fibrous connective tissue. The elbow is shown.

45. Read article about Tommy John’s surgery.

46. WHICH OF THE FOLLOWING IS A CORRECT STATEMENT? A A SYMPHYSIS IS FOUND BETWEEN T 12 AND L 1 B MARFAN SYNDROME IS CAUSED BY DEFECTIVE FIBRILLIN C ARTICULAR CARTILAGE IS AVASCULAR D SYNCHONDROSES MAY BECOME SYNOSTOSES E ALL OF THE ABOVE

47. Bursae are fibrous saclike structures that contain synovial fluid and are lined with synovial membrane

49. Numerous tendon sheaths are found spanning the wrist and ankle joints

50. Tendons , which are not part of the joint itself, are composed of dense fibrous connective tissue. Tendons connect muscles to bones and help stabilize joints. They sometimes limit the range of motion of the joint.

51. Planar (gliding) joints are uniaxial. Examples are intercarpal joints and intertarsal joints

52. The articulating processes (superior articular processes of one vertebrae articulate with inferior articular processes of another vertebrae) of adjacent vertebrae are diarthrotic synovial gliding (planar) joints .

53. Note that that the spine is a synovial gliding (planar) joint between the vertebral articular processes and an amphiarthrotic symphysis between the vertebral bodies.

54. Hinge joints are uniaxial joints

56. The interphalangeal joints are diarthrotic synovial hinge joints. They are uniaxial.

57. The proximal articulation between the head of the radius and the radial notch of the ulna is a diarthrotic synovial pivot joint . It is uniaxial.

59. The atlantoaxial joint is a diarthrotic synovial pivot joint that allows the head to move side to side in a “no” motion. It is uniaxial.

60. Atlantoaxial joint demonstrating side-to-side “no” motion

61. Condyloid joint is when an oval convex surface of one bone fits into an elliptical concave depression of another bone. It is biaxial.

62. Metacarpophalangeal joints for fingers #2 through #5 are diarthrotic synovial condyloid joints.

63. The radiocarpal joint is an example of a diarthrotic synovial condyloid joint . It is biaxial.

64. A saddle joint is found between the carpals and the first metacarpal bone. If gives us an opposable thumb! It is biaxial.

65. Malleus Incus The articulation between the malleus and the incus in the middle ear is another example of a biaxial saddle joint .

66. The acetabulofemoral (hip) joint is a diarthrotic synovial ball-and-socket joint . It is multiaxial.

67. The glenohumeral (shoulder) joint is a diarthrotic synovial ball-and-socket joint . It is multiaxial.

68. The ball-and-socket joints of the shoulder and hip provide great range of motion ! They are multiaxial.

69. IN THE ARTICLE “CAN HIS HIP BE SAVED?”, THE DOCTOR WAS VERY FEARFUL WHILE TREATING A 25-YEAR-OLD MALE’S HIP DISLOCATION. WHY? A HYPOVOLEMIC SHOCK B DEATH OF OSTEOCYTES C INABILITY TO REMOVE ISINGLASS WITH BULLDOG ARTERY FORCEPS D SYNOVIAL FLUID CAVITATION E ALL OF THE ABOVE

70. Bones act as levers to help move the resistance (R), the muscles provide the force or effort (E), and the joints act as pivots or fulcra (F).

71. Ankle Gliding motion is a simple movement in which two opposing surfaces slide slightly back-and-forth or side-to-side to one another. The angle between the bones does not change.

74. Adducted arm and adducted fingers Abducted arm and adducted fingers Abducted arm and abducted fingers

75. Despite what is shown in this picture, flexion and extension occur in an anterior-posterior plane!

76. Flexion and of the knee and hip followed by extension of both Flexion Extension

77. Flexion of the vertebral column by contraction of the rectus abdominus muscles.

78. Lateral flexion decreases a joint angle in a coronal plane. This type of movement occurs primarily between the vertebrae in the cervical and lumbar regions of the vertebral column.

79. Despite what is shown in this picture, flexion and extension occur in an anterior-posterior plane!

80. In the anatomical position all of the joints are fully extended (at a 180 degrees, except for the ankle joint which is at 90 degrees.

83. Tetanus is a bacterial infection that leads to severe muscle contractions. The hyperextended spine is called opisthotonos .

84. Hyperextension of the knee will cause severe damage to the joint capsule and associated ligaments! Rugby

86. Circumduction of ball-and-socket joints.

87. Rotation of head by use of atlantoaxial joint

88. Excessive rotation of atlantoaxial joint!

90. The rotation shown is possible because of the diarthrotic synovial pivot joint between the head of the radius and the radial notch on the nearby ulna

94. THE CALF MUSCLES UTILIZE THE ACHILLES TENDON TO INSERT ONTO THE CALCANEUS. WHEN THESE MUSCLES CONTRACT, WHAT WILL OCCUR ? A PLANTARFLEXION B CIRCUMDUCTION C ABDUCTION D DORSIFLEXION E MOVEMENT OF A CONDYLOID JOINT

98. pronated supinated

100. Hugh Grant demonstrating protraction and retraction of the pelvic girdle in the movie “Music and Lyrics”.