Structure and function of cartilage and joints

What is cartilage?

Specialized connective tissue that provides structural support, shock absorption, and a template for bone growth.

What are the main types of cartilage?

Hyaline cartilage, elastic cartilage, and fibrocartilage.

What are the main components of cartilage matrix?

Water (70%), Type II collagen, and proteoglycans.

What is the primary cell type in cartilage?

Chondrocytes.

What is the difference between chondroblasts and chondrocytes?

Chondroblasts are active cartilage-producing cells; chondrocytes are mature, less active cartilage-maintaining cells.

What is the function of proteoglycan aggregates in cartilage?

They provide compressive strength and flexibility.

What is hyaline cartilage and where is it found?

Smooth, glassy cartilage (Type II collagen) found in joints, nose, trachea, and growth plates.

What is elastic cartilage and where is it found?

Cartilage with elastin fibers, providing flexibility, found in the ear and epiglottis.

What is fibrocartilage and where is it found?

Strong cartilage with Type I and II collagen, found in intervertebral discs and pubic symphysis.

What are the two main types of joints?

Synovial (free movement) and non-synovial (limited movement).

What is a synovial joint?

A joint with a fluid-filled cavity, articular cartilage, and a surrounding fibrous capsule.

What is a non-synovial joint?

A joint with no fluid-filled cavity, connected by fibrous or cartilaginous tissue.

What is the main function of synovial fluid?

To lubricate the joint, reducing friction.

What is osteoarthritis (OA)?

A degenerative joint disease characterized by loss of cartilage, osteophytes, and subchondral sclerosis.

What are the key symptoms of osteoarthritis?

Joint pain, stiffness, reduced range of motion, and bone spurs.

What is rheumatoid arthritis (RA)?

An autoimmune, systemic inflammatory disease that mainly affects joints.

What are the key symptoms of rheumatoid arthritis?

Joint pain, swelling, stiffness, and deformities, often affecting small joints.

What is bursitis?

Inflammation of a bursa, causing pain and swelling, usually due to repetitive movement.

What is gout?

A type of arthritis caused by the deposition of urate crystals in joints due to high blood uric acid.

What is pseudogout?

A condition similar to gout but caused by calcium pyrophosphate crystals instead of urate.