1. The Skeletal System: Joints

2. Joints Articulations of bones Functions of joints Hold bones together
Allow for mobility
Ways joints are classified
Functionally- by degree of movement
Structurally- by type of connective tissue

3. Functional Classification of Joints
Synarthroses
Immovable joints
Amphiarthroses
Slightly moveable joints
Diarthroses
Freely moveable joints

4. Structural Classification of Joints
Fibrous joints
Generally immovable
Cartilaginous joints
Immovable or slightly moveable
Synovial joints
Freely moveable

5. Summary of Joint Classes
[Insert Table 5.3 here]
Table 5.3

6. Fibrous Joints- Synarthroses or Immoveable
Bones united by fibrous tissue
Example:
Sutures
Syndesmoses
Ligaments attach two bones
Allows more movement than sutures
Example: Distal end of tibia and fibula
Example: Distal end of radium and ulna

7. Fibrous Joints- Synarthroses or Immoveable
Gomphoses- joint created by alveolar processes to hold teeth in

8. Fibrous Joints
Figure 5.28a–b

9. Cartilaginous Joints Bones connected by cartilage Example:
Symphysis joints- fibrocartilage
Pubic symphysis
Intervertebral joints
Synchondroses- hyaline cartilage
Connect ribs to sternum

10. Cartilaginous Joints
Figure 5.28c–e

11. Synovial Joints Most moveable, most numerous, and most complex
Articulating bones are separated by a joint cavity
Synovial fluid is found in the joint cavity

12. Synovial Joints
Figure 5.28f–h

13. Features of Synovial Joints
Articular cartilage (hyaline cartilage) covers the ends of bones
A fibrous articular capsule encloses joint surfaces
A joint cavity is filled with synovial fluid
Synovial membrane secretes synovial fluid
Ligaments reinforce the joint

14. Structures Associated with the Synovial Joint
Bursae—flattened fibrous sacs
Lined with synovial membranes
Filled with synovial fluid
Not actually part of the joint
Tendon sheath
Elongated bursa that wraps around a tendon

15. Synovial Knee Joint

16. The Synovial Joint
Figure 5.29

17. Types of Synovial Joints
Nonaxial
Gliding does not involve rotation around axis
Plane joint – intercarpal joints of wrist
Uniaxial
Permit movement on one plane
Hinge Joint like jaw, knee, elbow
Pivot Joint- 1st and 2nd vertebrae

18. Types of Synovial Joints
Figure 5.30a–c

19. Types of Synovial Joints
Biaxial
Permit movements in two planes
Saddle joint of thumb
Condyloid or ellipsoidal
Condyloid on bone fits into ellipsoidal socket like radius and carpal bones
Multiaxial
Movement in three or more planes
Ball and socket joints like hip and shoulder

20. Types of Synovial Joints
Figure 5.30d–f

21. Types of Ordinary Body Movements
Flexion
Decreases the angle of the joint
Brings two bones closer together
Typical of hinge joints like knee and elbow
Extension
Opposite of flexion
Increases angle between two bones
Hyperextension
Stretching beyond anatomical position

22. Types of Ordinary Body Movements
Figure 6.13a

23. Types of Ordinary Body Movements
Figure 6.13b

24. Types of Ordinary Body Movements
Abduction
Movement of a limb away from the midline
Adduction
Opposite of abduction
Movement of a limb toward the midline

25. Types of Ordinary Body Movements
Figure 6.13d

26. Types of Ordinary Body Movements
Rotation
Movement of a bone around its longitudinal axis
Common in ball-and-socket joints
Example is when you move atlas around the dens of axis (shake your head “no”)

27. Types of Ordinary Body Movements
Figure 6.13c

28. Types of Ordinary Body Movements
Circumduction
Combination of flexion, extension, abduction, and adduction
Common in ball-and-socket joints

29. Types of Ordinary Body Movements
Figure 6.13d

30. Special Movements Dorsiflexion
Lifting the foot so that the superior surface approaches the shin
Plantar flexion
Depressing the foot (pointing the toes)

31. Special Movements
Figure 6.13e

32. Special Movements Inversion Turn sole of foot medially Eversion
Turn sole of foot laterally

33. Special Movements
Figure 6.13f

34. Special Movements Supination
Forearm rotates laterally so palm faces anteriorly
Pronation
Forearm rotates medially so palm faces posteriorly

35. Special Movements
Figure 6.13g

36. Special Movements Opposition
Move thumb to touch the tips of other fingers on the same hand

37. Special Movements
Figure 6.13h

38. Special Movements Protraction- stick something out like jaw
Retraction- pull jaw back in
Elevation- move something up like close mouth
Depression- lower something like the mouth

39. Joint Replacement
Total hip replacement most common orthopedic surgery done on older people

40. Range of Motion
Used to determine degree of damage to an injured joint
Active- you move
Passive- Dr. moves
Goniometer used to measure range of motion
ROM greatest early in life

41. Knee Joint Largest, most complex, and most injured joint
Anterior cruciate ligament tear is common
Compared to hip, it is relatively unprotected and easily injured
Knee injury can be very crippling

42. Two small puncture wounds
Arthroscopy
Imaging technique
Two small puncture wounds
One for tube with lens and small light
One with knife

43. Inflammatory Conditions Associated with Joints
Bursitis—inflammation of a bursa usually caused by a blow or friction
Dislocation- frequent joint injury
Tendonitis—inflammation of tendon sheaths
Sprain- injury to ligaments around a joint
Strain- overstretching of a muscle

44. Inflammatory Conditions Associated with Joints
Arthritis—inflammatory or degenerative diseases of joints
Over 100 different types
The most widespread crippling disease in the United States

45. Clinical Forms of Arthritis
Osteoarthritis
Most common chronic arthritis
Probably related to normal aging processes
Caused by deterioration of cartilage
Rheumatoid arthritis
An autoimmune disease—the immune system attacks the joints
Symptoms begin with bilateral inflammation of certain joints
Often leads to deformities
More common in women

46. Clinical Forms of Arthritis
Gouty arthritis
Inflammation of joints is caused by a deposition of uric acid crystals from the blood
Can usually be controlled with diet
More common in men

47. Developmental Aspects of the Skeletal System
At birth, the skull bones are incomplete
Bones are joined by fibrous membranes called fontanels
Fontanels are completely replaced with bone within two years after birth

48. Ossification Centers in a 12-week-old Fetus
Figure 5.32

49. Skeletal Changes Throughout Life
Fetus
Long bones are formed of hyaline cartilage
Flat bones begin as fibrous membranes
Flat and long bone models are converted to bone
Birth
Fontanels remain until around age 2

50. Skeletal Changes Throughout Life
Adolescence
Epiphyseal plates become ossified and long bone growth ends
Size of cranium in relationship to body
2 years old—skull is larger in proportion to the body compared to that of an adult
8 or 9 years old—skull is near adult size and proportion
Between ages 6 and 11, the face grows out from the skull

51. Skeletal Changes Throughout Life
Figure 5.33a

52. Skeletal Changes Throughout Life
Figure 5.33b

53. Skeletal Changes Throughout Life
Osteoporosis
Bone-thinning disease afflicting
50% of women over age 65
20% of men over age 70
Disease makes bones fragile and bones can easily fracture
Vertebral collapse results in kyphosis (also known as dowager’s hump)
Estrogen aids in health and normal density of a female skeleton

54. Skeletal Changes Throughout Life
Figure 5.34

55. Advances in Bone Repair
Electrical stimulation of fracture sites
Bone tissue deposited in places of negative charge
Ultrasound- stimulates cartilage cells to make callus
Bone Grafting- Take part of bone from hip and put between two bones that have gap
Now using vascular fibular grafts

56. Advances in Bone Repair
Bone substitutes
Ground cadavar bone
ProOsteon from coral
Ceramic bone substitutes