1. Joints

2. A joint is the location at which 2 or more bones make contact Joints, also called articulations, have 2 functions: 1.They hold bones together securely 2.They give the rigid skeleton mobility Joints are classified in 2 ways: Functionally and Structurally

3. Functionally The functional classification focuses on the amount of movement allowed by the joint There are: 1.Synarthroses: Immovable joints 2.Amphiarthroses: Slightly movable joints 3.Diarthroses: Freely movable joints Synarthroses and Amphiarthroses are restricted mainly to the axial skeleton Diarthroses predominate in the limbs

4. Structurally Structurally, there are: 1.Fibrous joints 2.Cartilaginous joints 3.Synovial joints As a general rule, fibrous joints are immovable and synovial joints are freely movable and most cartilaginous joints are amphiarthrotic

5. Fibrous Joints In fibrous joints, the bones are united by fibrous tissue e.g. sutures of the skull

6. Cartilaginous Joints In cartilaginous joints, the bone ends are connected by cartilage Cartilaginous joints allow more movement between bones than a fibrous joint but less than the highly mobile synovial joint e.g. intervertebral joints

7. Synovial Joints Synovial joints are those in which the articulating bone ends are separated by a joint cavity containing synovial fluid All synovial joints have 4 distinguishing features: 1.Articular cartilage 2.Fibrous articular capsule 3.Joint cavity 4.Reinforcing ligaments

8. Synovial Joints Articular cartilage: covers the ends of the bones forming the joint Fibrous articular capsule: The joint surfaces are enclosed by a sleeve or capsule of fibrous connective tissue and the capsule is covered with a smooth synovial membrane

9. Synovial Joints Joint cavity: the articular capsule encloses a cavity, called the joint cavity, which contains lubricating synovial fluid Reinforcing ligaments: the fibrous capsule is usually reinforced with ligament (connection between bone to bone)

10. Inflammatory Disorders Arthritis: describes over 100 different inflammatory or degenerative diseases that damage the joints Acute forms of arthritis usually result from bacterial invasion and are treated with antibiotic drugs Chronic forms of arthritis include: osteoarthritis, rheumatoid arthritis, and gouty arthritis

11. Osteoarthritis (OA) The most common form of arthritis Also called “wear and tear” arthritis Affects the articular cartilages: over the years, there is a softening, fraying and eventual breaking down of the cartilage As the disease progresses, the exposed bone thickens and extra bone tissue, called bone spurs, grows around the margin of the eroded cartilage

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13. Rheumatoid Arthritis (RA) It is an autoimmune disease: a disorder in which the body’s immune system attempts to destroy its own tissue Movie

14. Gouty Arthritis (gout) A disease in which uric acid accumulates in the blood and may be deposited as crystal in the soft tissues of joints Movie