1. Joints
Skeletal System - Part 3

2. Joints
With one exception (the hyoid bone), EVERY bone in the body forms a joint with at least one other bone.
Joints have 2 functions:
Hold bones together
Give skeleton mobility
Also known as articulations

3. Classification of Joints
Functional – how much movement allowed
Synarthroses - immovable
Amphiarthroses - slightly movable
Axial skeleton
Diarthroses - freely movable
Appendicular Skeleton

4. Classification of Joints
Structural – what the joint is made of
Fibrous - bones joined by fibrous connective tissue; no joint cavity
Cartilaginous - bones joined by cartilage; no joint cavity
Synovial - bones separated by fluid filled cavity

5. Fibrous Joints Characteristics
Almost no movement allowed
Sutures – irregular bone edges interlock by connective tissue (ex: skull bones)
Syndesmosis – joint connected by long fibers that allow a small amount of movement (ex: tibia and fibula joint)

6. Cartilaginous Joints Characteristics
Slight movement allowed
Bones connected by cartilage
Found in the pelvis and intervertebral column

7. Synovial Joints General Structure Articular cartilage
Synovial (joint) cavity
Articular capsule
Synovial fluid
Reinforcing ligaments (fibrous tissue connecting bones)

8. Synovial Joints Bursae - flattened sacs filled with synovial fluid
Tendon sheath - elongated bursa which wraps around a tendon

9. Different joint types are located in various areas throught your body!

10. Synovial Joints Gliding (plane) joint
Only gliding or slipping movements allowed
Ex: Wrist joints

11. Synovial Joints Hinge Joint Only angular movement allowed
Cylindrical projection fits into a notch
Ex: ulna and humerus
Ex: tibia and femur
Ex: interphalangeal joints

12. Synovial Joints Pivot Joint
Rounded end of one bone protrudes into sleeve or ring of bone or ligaments
Ex: atlas (C1) and axis (C2)
Ex: radioulnar joint

13. Synovial Joints Condyloid Joint
Rounded (convex) articulating surface of one bone fits into concave depression on the other bone
Side to side and back and forth movement
Ex: radio-carpal joints
Ex: metacarpal- phalangeal joints

14. Synovial Joints Saddle Joint
Each articular surface has both convex and concave areas – look like saddles
Ex: carpo-metacarpal joint of the thumb (so you can twiddle your thumb)

15. Synovial Joints Ball and Socket
Spherical head of one bone articulates with cuplike socket
Provides greatest rotational flexibility
Ex: shoulder, hip

16. Dislocation
Occurs when a bone is forced out of its normal position in a joint cavity

17. Inflammatory and Degenerative Conditions
Bursitis
An inflammation of a bursa, usually caused by a blow or friction
Symptoms are pain and swelling
Tendonitis
Inflammation of tendon sheaths typically caused by overuse
Symptoms are similar to bursitis

18. Joint Disorder - Arthritis
More than 100 different types of inflammatory or degenerative joint diseases
Most common crippling diseases in the U.S.
Symptoms – pain, stiffness, and swelling of joint(s)
Chronic forms include osteoarthritis (OA), rheumatoid arthritis, and gouty arthritis

19. Rheumatoid Arthritis X-ray

20. Osteoporosis Bone-thinning disease
Affects half of women over 65 and 20% of men over 70
Sneezing can cause bone to break they are so brittle
After menopause estrogen levels (female hormone) drop, this is one of the causes of osteoporosis
Other factors:
Low calcium and low protein diet
Lack of vitamin D
Smoking
Sedentary lifestyle

21. Osteoporosis