1. Articulations and Joints
Muse lecture #9
6/7/10

2. Joints Chapter 9 Joint Classifications Fibrous Joints
Cartilaginous Joints
Synovial Joints
Types of Movements at Synovial Joints
Types of Synovial Joints
Factors Affecting Contact and Range of Motion at Synovial Joints
Selected Joints of the Body
Aging and Joints
Arthroplasty
Muse Lecture #6

3. An Introduction to Articulations
Body movement occurs at joints (articulations) where two bones connect
Joint Structure
Determines direction and distance of movement (range of motion)
Joint strength decreases as mobility increases

4. Classification of Joints
Two methods of classification
Functional classification is based on range of motion of the joint
Structural classification relies on the anatomical organization of the joint

5. Classification of Joints
Functional Classifications
Synarthrosis (immovable joint)
No movement
Fibrous or cartilaginous connections
May fuse over time
Amphiarthrosis (slightly movable joint)
Little movement
Diarthrosis (freely movable joint)
More movement
Also called synovial joints
Subdivided by type of motion
Party on Arth!

6. Classification of Joints

7. Classification of Joints

8. Classification of Joints
Structural Classifications
Bony
Fibrous
Cartilaginous
Synovial (capsulated)

9. Classification of Joints

10. Classification of Joints
Functional Classifications
Synarthroses (immovable joints)
Are very strong
Edges of bones may touch or interlock
Four types of synarthrotic joints:
suture
gomphosis
synchondrosis
synostosis

11. Classification of Joints
Synarthrotic Joints
Suture
Bones interlocked
Are bound by dense fibrous connective tissue
Are found only in skull
Gomphosis
Fibrous connection (periodontal ligament)
Binds teeth to sockets
Yah can’t chomp without the gomph

12. Joints (Fibrous Joints)
Sutures
Occur only between bones of the skull
Syndesmoses
Permits slight movement
Interosseous membrane
Between the tibia and fibula in the leg
Gomphoses
Immovable joint
Joint in which a cone-shaped peg fits into a socket
Articulations of the teeth with the sockets of the maxillae and mandible

13. (b) Syndesmosis Joint held together by a ligament.
Fibrous tissue can vary in length, but
is longer than in sutures.
Fibula
Tibia
Ligament
Figure 8.1b

14. Joints (Fibrous Joints)
Lack a synovial cavity
The articulating bones are held very closely together by dense irregular connective tissue
Fibrous joints permit little or no movement
Three types of fibrous joints
Sutures
Syndesmoses
Gomphoses

15. Classification of Joints
Synarthrotic Joints
Synchondrosis
Is a rigid cartilaginous bridge between two bones:
epiphyseal cartilage of long bones
between vertebrosternal ribs and sternum
Synostosis
Fused bones, immovable:
metopic suture of skull
epiphyseal lines of long bones

16. Classification of Joints
Functional Classifications
Amphiarthroses
More movable than synarthrosis
Stronger than freely movable joint
Two types of amphiarthroses
syndesmosis:
bones connected by ligaments
symphysis:
bones separated by fibrous cartilage

17. Classification of Joints
Functional Classifications
Synovial joints (diarthroses)
Also called movable joints
At ends of long bones
Within articular capsules
Lined with synovial membrane

18. Synovial Joints Components of Synovial Joints Articular cartilages
Pad articulating surfaces within articular capsules:
prevent bones from touching
Smooth surfaces lubricated by synovial fluid:
reduce friction

19. Ligament Joint cavity (contains synovial fluid) Articular (hyaline)
cartilage
Fibrous
capsule
Articular
capsule
Synovial
membrane
Periosteum
Figure 8.3

20. Synovial Joints Components of Synovial Joints Synovial fluid
Contains slippery proteoglycans secreted by fibroblasts
Functions of synovial fluid:
lubrication
nutrient distribution
shock absorption

21. Synovial Joints Components of Synovial Joints Accessory structures
Cartilages:
cushion the joint:
Fibrous cartilage pad called a meniscus (articular disc)
Fat pads:
superficial to the joint capsule
protect articular cartilages
Ligaments:
support, strengthen joints
sprain: ligaments with torn collagen fibers

22. Synovial Joints Components of Synovial Joints Accessory structures
Tendons:
attach to muscles around joint
help support joint
Bursae:
pockets of synovial fluid
cushion areas where tendons or ligaments rub

23. Coracoacromial ligament Subacromial bursa Humerus resting Cavity in
bursa containing
synovial fluid
Bursa rolls
and lessens
friction.
Humerus head
rolls medially as
arm abducts.
Humerus
moving
(b) Enlargement of (a), showing how a bursa eliminates friction where a ligament (or other structure) would rub against a bone
Figure 8.4b

24. Synovial Joints Factors That Stabilize Synovial Joints
Prevent injury by limiting range of motion
Collagen fibers (joint capsule, ligaments)
Articulating surfaces and menisci
Other bones, muscles, or fat pads
Tendons of articulating bones

25. Synovial Joints [INSERT FIG. 9.1a]
Figure 9–1a The Structure of a Synovial Joint.

26. Synovial Joints
Figure 9–1b The Structure of a Synovial Joint.

27. Synovial Joints Injuries Dislocation (luxation) Subluxation
Articulating surfaces forced out of position
Damages articular cartilage, ligaments, joint capsule
Subluxation
A partial dislocation

28. Movements Types of Dynamic Motion Planes (Axes) of Dynamic Motion
Linear motion (gliding)
Angular motion
Rotation
Planes (Axes) of Dynamic Motion
Monaxial (1 axis)
Biaxial (2 axes)
Triaxial (3 axes)

29. Movements
Figure 9–2 A Simple Model of Articular Motion.

30. Movements
Figure 9–2 A Simple Model of Articular Motion.

31. Movements Types of Movements at Synovial Joints Terms describe
Plane or direction of motion
Relationship between structures

32. Movements Types of Movements at Synovial Joints Linear motion
Also called gliding
Two surfaces slide past each other:
between carpal or tarsal bones

33. Movements Angular Motion Flexion Extension Angular motion
Anterior–posterior plane
Reduces angle between elements
Extension
Increases angle between elements

34. Movements Angular Motion Hyperextension Angular motion
Extension past anatomical position
Angular Movements

35. Movements
Figure 9–3a Angular Movements.

36. Movements Angular Motion Abduction Adduction Angular motion
Frontal plane
Moves away from longitudinal axis
Adduction
Moves toward longitudinal axis
Think kidnapping
Think adding

37. Movements
Figure 9–3 Angular Movements.

38. Movements
Figure 9–3 Angular Movements.

39. Movements Angular Motion Circumduction
Circular motion without rotation
Angular motion

40. Movements
Figure 9–3 Angular Movements.

41. Movements Types of Movement at Synovial Joints Rotation
Direction of rotation from anatomical position
Relative to longitudinal axis of body
Left or right rotation
Medial rotation (inward rotation):
rotates toward axis
Lateral rotation (outward rotation):
rotates away from axis

42. Movements
Figure 9–4a Rotational Movements.

43. Movements Types of Movements at Synovial Joints Rotation Pronation:
rotates forearm, radius over ulna
Supination:
forearm in anatomical position

44. Movements
Figure 9–4b Rotational Movements.

45. Movements Types of Movements at Synovial Joints Special movements
Inversion:
twists sole of foot medially
Eversion:
twists sole of foot laterally
Dorsiflexion:
flexion at ankle (lifting toes)
Plantar flexion:
extension at ankle (pointing toes)
Plant your feet

46. Movements Special Movements at Synovial Joints Opposition
Thumb movement toward fingers or palm (grasping)
Protraction
Moves anteriorly
In the horizontal plane (pushing forward)
Retraction
Opposite of protraction
Moving anteriorly (pulling back)

47. Movements Special Movements at Synovial Joints Elevation Depression
Moves in superior direction (up)
Depression
Moves in inferior direction (down)
Lateral flexion
Bends vertebral column from side to side

48. Movements
Figure 9–5 Special Movements.

49. Movements
Figure 9–5 Special Movements.

50. Movements Classification of Synovial Joints by Shape Gliding Hinge
Pivot
Ellipsoid
Saddle
Ball-and-socket
A Functional Classification of Synovial Joints

51. Movements Gliding Joints Hinge Joints Pivot Joints
Flattened or slightly curved faces
Limited motion (nonaxial)
Hinge Joints
Angular motion in a single plane (monaxial)
Pivot Joints
Rotation only (monaxial)

52. Movements
Figure 9–6 Movements at Synovial Joints.

53. Movements Ellipsoid Joints Saddle Joints Ball-and-Socket Joints
Oval articular face within a depression
Motion in two planes (biaxial)
Saddle Joints
Two concave, straddled (biaxial)
Ball-and-Socket Joints
Round articular face in a depression (triaxial)

54. Movements
Figure 9–6 Movements at Synovial Joints.

55. Movements A joint cannot be both mobile and strong
The greater the mobility, the weaker the joint
Mobile joints are supported by muscles and ligaments, not bone-to-bone connections

56. Intervertebral Articulations
C2 to L5 spinal vertebrae articulate
At inferior and superior articular processes (gliding joints)
Between adjacent vertebral bodies (symphyseal joints)

57. Intervertebral Articulations
C2 to L5 spinal vertebrae articulate
Intervertebral discs:
pads of fibrous cartilage
separate vertebral bodies
anulus fibrosus:
tough outer layer
attaches disc to vertebrae
nucleus pulposus:
elastic, gelatinous core
absorbs shocks

58. Intervertebral Articulations
Figure 9–7 Intervertebral Articulations.

59. Intervertebral Articulations
Vertebral Joints
Also called symphyseal joints
As vertebral column moves
Nucleus pulposus shifts
Disc shape conforms to motion
Intervertebral Ligaments
Bind vertebrae together
Stabilize the vertebral column

60. Intervertebral Articulations
Six Intervertebral Ligaments
Anterior longitudinal ligament
Connects anterior bodies
Posterior longitudinal ligament
Connects posterior bodies
Ligamentum flavum
Connects laminae

61. Intervertebral Articulations
Six Intervertebral Ligaments
Interspinous ligament
Connects spinous processes
Supraspinous ligament
Connects tips of spinous processes (C7 to sacrum)
Ligamentum nuchae
Continues supraspinous ligament (C7 to skull)

62. Intervertebral Articulations
Damage to Intervertebral Discs
Slipped disc
Bulge in anulus fibrosus
Invades vertebral canal
Herniated disc
Nucleus pulposus breaks through anulus fibrosus
Presses on spinal cord or nerves

63. Intervertebral Articulations
Figure 9–8a Damage to the Intervertebral Discs.

64. Intervertebral Articulations
Figure 9–8b Damage to the Intervertebral Discs.

65. Intervertebral Articulations
Movements of the Vertebral Column
Flexion
Bends anteriorly
Extension
Bends posteriorly
Lateral flexion
Bends laterally
Rotation
Turning

66. Articulations of the Axial Skeleton

67. Articulations of the Axial Skeleton

68. Articulations of the Axial Skeleton

69. Joints (Selected Joints of the Body)
Temporomandibular Joint
Combined hinge and planar joint formed by the mandible and the temporal bone
Only movable joint between skull bones
Only the mandible moves

70. Lateral excursion: lateral (side-to-side) movements of the mandible
Superior view
Outline of
the mandibular
fossa
Lateral excursion: lateral (side-to-side) movements of the
mandible
Figure 8.13c

71. (a) Location of the joint in the skull
Mandibular fossa
Articular tubercle
Zygomatic process
Infratemporal fossa
External
acoustic
meatus
Lateral
ligament
Articular
capsule
Ramus of
mandible
(a) Location of the joint in the skull
Figure 8.13a

72. (b) Enlargement of a sagittal section through the joint
Articular disc
Articular
tubercle
Mandibular
fossa
Superior
joint
cavity
Articular
capsule
Synovial
membranes
Mandibular
condyle
Ramus of
mandible
Inferior joint
cavity
(b) Enlargement of a sagittal section through the joint
Figure 8.13b

73. The Shoulder Joint Also called the glenohumeral joint
Allows more motion than any other joint
Is the least stable
Supported by skeletal muscles, tendons, ligaments
Ball-and-socket diarthrosis
Between head of humerus and glenoid cavity of scapula

74. The Shoulder Joint Socket of the Shoulder Joint
Glenoid labrum
Deepens socket of glenoid cavity
Fibrous cartilage lining
Extends past the bone
Processes of the Shoulder Joint
Acromion (clavicle) and coracoid process (scapula)
Project laterally, superior to the humerus
Help stabilize the joint

75. The Shoulder Joint Shoulder Ligaments Shoulder Separation Glenohumeral
Coracohumeral
Coraco-acromial
Coracoclavicular
Acromioclavicular
Shoulder Separation
Dislocation of the shoulder joint

76. The Shoulder Joint Shoulder Muscles (also called rotator cuff)
Supraspinatus
Infraspinatus
Subscapularis
Teres minor
Shoulder Bursae
Subacromial
Subcoracoid
Subdeltoid
Subscapular

77. The Shoulder Joint
Figure 9–9a The Shoulder Joint.

78. The Shoulder Joint
Figure 9–9b The Shoulder Joint.

79. The Elbow Joint A stable hinge joint
With articulations involving humerus, radius, and ulna

80. The Elbow Joint Articulations of the Elbow Humero-ulnar joint
Largest articulation
Trochlea of humerus and trochlear notch of ulna
Limited movement
Humeroradial joint:
Smaller articulation
Capitulum of humerus and head of radius

81. The Elbow Joint
Figure 9–10a The Elbow Joint.

82. The Elbow Joint Supporting Structures of the Elbow
Biceps brachii muscle
Attached to radial tuberosity
Controls elbow motion
Elbow Ligaments
Radial collateral
Annular
Ulnar collateral

83. The Elbow Joint
Figure 9–10b The Elbow Joint.

84. The Hip Joint Also called coxal joint
Strong ball-and-socket diarthrosis
Wide range of motion

85. The Hip Joint Structures of the Hip Joint Ligaments of the Hip Joint
Head of femur fits into it
Socket of acetabulum
Which is extended by fibrocartilaginous acetabular labrum
Ligaments of the Hip Joint
Iliofemoral
Pubofemoral
Ischiofemoral
Transverse acetabular
Ligamentum teres

86. The Hip Joint
Figure 9–11a The Hip Joint.

87. The Hip Joint
Figure 9–11b The Hip Joint.

88. The Hip Joint
Figure 9–11c The Hip Joint.

89. The Knee Joint A complicated hinge joint
Transfers weight from femur to tibia
Articulations of the knee joint
Two femur–tibia articulations
At medial and lateral condyles
One between patella and patellar surface of femur

90. The Knee Joint Menisci of the Knee Medial and lateral menisci
Fibrous cartilage pads
At femur–tibia articulations
Cushion and stabilize joint
Give lateral support
Locking knees
Standing with legs straight:
“locks” knees by jamming lateral meniscus between tibia and femur

91. The Knee Joint Seven Ligaments of the Knee Joint
Patellar ligament (anterior)
Two popliteal ligaments (posterior)
Anterior and posterior cruciate ligaments (inside joint capsule)
Tibial collateral ligament (medial)
Fibular collateral ligament (lateral)

92. The Knee Joint
Figure 9–12a The Knee Joint.

93. The Knee Joint
Figure 9–12b The Knee Joint.

94. The Knee Joint
Figure 9–12c The Knee Joint.

95. The Knee Joint
Figure 9–12d The Knee Joint.

96. Torn
meniscus
Figure 8.14

97. The Knee Joint

98. The Knee Joint

99. Aging Rheumatism Arthritis Osteoarthritis
A pain and stiffness of skeletal and muscular systems
Arthritis
All forms of rheumatism that damage articular cartilages of synovial joints
Osteoarthritis
Caused by wear and tear of joint surfaces, or genetic factors affecting collagen formation
Generally in people over age 60

100. Developmental Aspects of Joints
By embryonic week 8, synovial joints resemble adult joints
A joint’s size, shape, and flexibility are modified by use
Advancing years take their toll on joints:
Ligaments and tendons shorten and weaken
Intervertebral discs become more likely to herniate
Most people in their 70s have some degree of OA
Exercise that coaxes joints through their full range of motion is key to postponing joint problems

101. Aging Rheumatoid Arthritis Gouty Arthritis An inflammatory condition
Caused by infection, allergy, or autoimmune disease
Involves the immune system
Gouty Arthritis
Occurs when crystals (uric acid or calcium salts)
Form within synovial fluid
Due to metabolic disorders

102. Rheumatoid Arthritis RA begins with synovitis of the affected joint
Inflammatory blood cells migrate to the joint, release inflammatory chemicals
Inflamed synovial membrane thickens into a pannus
Pannus erodes cartilage, scar tissue forms, articulating bone ends connect (ankylosis)

103. Figure 8.15

104. Gouty Arthritis
Deposition of uric acid crystals in joints and soft tissues, followed by inflammation
More common in men
Typically affects the joint at the base of the great toe
In untreated gouty arthritis, the bone ends fuse and immobilize the joint
Treatment: drugs, plenty of water, avoidance of alcohol

105. Aging Joint Immobilization Bones and Aging
Reduces flow of synovial fluid
Can cause arthritis symptoms
Treated by continuous passive motion (therapy)
Bones and Aging
Bone mass decreases
Bones weaken
Increases risk of hip fracture, hip dislocation, or pelvic fracture

106. Joints (Arthroplasty)
Joints may be replaced surgically with artificial joints
Most commonly replaced are the hips, knees, and shoulders
Hip Replacements
Partial hip replacements involve only the femur
Total hip replacements involve both the acetabulum and head of the femur
Knee Replacements
Actually a resurfacing of cartilage and may be partial or total
Potential complications of arthroplasty include infection, blood clots, loosening or dislocation of the replacement components, and nerve injury

107. Joints (Arthroplasty)

108. Joints (Arthroplasty)

109. Osteoarthritis (OA)
Common, irreversible, degenerative (“wear-and-tear”) arthritis
85% of all Americans develop OA, more women than men
Probably related to the normal aging process

110. Osteoarthritis (OA)
More cartilage is destroyed than replaced in badly aligned or overworked joints
Exposed bone ends thicken, enlarge, form bone spurs, and restrict movement
Treatment: moderate activity, mild pain relievers, capsaicin creams, glucosamine and chondroitin sulfate

111. Lyme Disease Caused by bacteria transmitted by the bites of ticks
Symptoms: skin rash, flu-like symptoms, and foggy thinking
May lead to joint pain and arthritis
Treatment: antibiotics

112. Integration with Other Systems
Bone Recycling
Living bones maintain equilibrium between
Bone building (osteoblasts)
And breakdown (osteoclasts)
Factors Affecting Bone Strength
Age
Physical stress
Hormone levels
Calcium and phosphorus uptake and excretion
Genetic and environmental factors

113. Integration with Other Systems
Bones Support Body Systems
The skeletal system
Supports and protects other systems
Stores fat, calcium, and phosphorus
Manufactures cells for immune system
Disorders in other body systems can cause
Bone tumors
Osteoporosis
Arthritis
Rickets (vitamin D deficiency)

114. Integration with Other Systems
Figure 9–13 Functional Relationships between the Skeletal System and Other Systems.

115. Integration with Other Systems
Figure 9–13 Functional Relationships between the Skeletal System and Other Systems.