What is cartilage?
A connective tissue made up of chondrocytes embedded in a matrix
What is the interceullar matrix composed of?
Proteoglycans, collagen fibres and water
What is the function of water, proteoglycans and collagen fibres?
Water: Lubrication and nourishment
Proteoglycans: Attract and hold water
Collagen fibres: keep proteoglycans in place
Is cartilage avascular and aneural?
What are th 3 main types of cartilage?
What is hyaline cartilage composed of?
Chondrytes: Located in lacunea(holes) arranged in a nest
Intercellular matrix: collagen fibres, proteoglycans and 70% water
What are proteoglycans and what are the most common?
Molecules of glycosaminoglycans(GAGs) attached to a core protein. Chondroltin and keratin sulphate
Where do you find hyaline cartilage?
-Epiphyseal plates(growth plates)
-Walls of respiratory passages
-Costal Cartilages (anterior end of ribs)
What is the main difference between hyaline and articular cartilage?
The organisation of its fibres
What is the arrangement of these fibres?
-Superficial zone: parallel to articular surface
-Deep zone: perpendicular to articular surfae
How does articular cartilage have a low coefficient of friction and a high tensile strength?
Strength: High concentration of collagen fibres
Friction: Parallel fibres act as barrier to hyaluronic acid, to keep it on surface of cartilage
How do the arches created between the zones inflate with water and swell?
Due to the proteoglycans in the deep zone
Why is this arrangement an ideal load-bearing surface that resist compression?
When there is a load some water is pushed out and then is reabsorbed once the load is removed
How is fibrocartilage different from hyaline or articular cartilage?
-Chondrytes are distributed individually or in pairs
-There is more collagen fibres, giving it a greater tensile strength
Where do you find fibrocartilage?
Intervertebral and articular discs
What are the two types of wear that can damage cartilage?
Fatigue and interfacial
What is the difference between fatigue and interfacial wear?
Fatigue: damage to intercellular matrix, caused by repetitive loading
Interfacial: damage to articular surfaces caused by lack of lubrication through abrasion or adhesion
Is fatigue or interfacial wear more common?
How does cartilage repair itself?
It can't, surgical intervention is usually required to remove damaged cartilage and replace with periosteal cells(tissue implants)