Cartilage

• Location
• 1) Fetal skeletal tissue
• 2) synovial joints
• 3) Trachea
• 4) others

• Function
• 1) resists compression (cusioning)
• 2) lowers friction
• 3) structural support (e.g. trachea)
• 4) endochondral ossification

• Location
• 1) pinna of ears
• 2) larynx
• 3) auditory tube

• Function:
• 1) Provides flexible support

• Location:
• 1) intervertebral discs
• 2) menisci
• 3) some joints
• 4) insertion of tendons

• Function
• 1) resists deformation under stress

• hyaline:
• aggrecan

• Elastic:
• Elastin fibres

• Fibrocartilage:
• Type I collagen (produced by fibroblasts)

• Development:
• Develops from the condensation of mesenchyme mesenchymal SC differentiate into chondroblasts

• appositional growth:
•  (at the edge) under perichodrium

• Interstitial growth:
• Chondroblasts/chondrocytes divide and then secrete matrix (isogenous groups)

• Intracellular
• 1) transcription of mRNA
• 2) Translation into polypeptides
• 3) Hydroxylation of lysines and prolines. Uses vitamin C as a cofactor. this aids in the crosslinking of alpha peptides (making the helix)
• 4) golgi apparatus modification

• Extracellular
• 5) formation of tropocollagen
• 6) formation of collagen fibril

- Fibrous CT

• - Provides vascular and nervous supply
• - perichondrial fibroblast-like cells differentiate into collagen II - producing cells

- no perichondrium, therefore there is very limited ability for self repair as mature chondrocytes dont readily divide

- remember your zonation from M.Sc.

- damaged cartilage is replaced by fibrovascular cartilage

- bone is highly vascular while cartilage is avascular

- cartilage is not innervated while bone is

through diffusion

• 1) advanced age
• 2) trauma
• 3) naturally during growth and development