Cartillage Flashcards
Characteristics of cartilage
- high conc of gag’s and proteoglycans
- tough durable
- has firm consistency allowing to resist mechanical stress
- has smooth low friction surface
- not vasculated
Functions of cartilage
- provides framework to support softer tissue
- smooth sliding surface for joints
- shock absorber due to trapped water.
- facilitates growth of bone
Cells of cartilage characteristics and their functions
- chondroblasts and chondrocytes
- synthesis and secrete ecm components
What allows cartilage to act as shock absorbers
-high content of water bound to hyaluronan
How do metabolites move to cells
-through diffusion via interstitial fluid mediated by compression and decompression of tissue during movement
Structure of perichondrium
- dense sheath of CT with collagen 1
- outer region has collagen 1 and fibroblasts
- inner region adjoining cartilage is mesenchymal stem cells
- has blood supply
Which cartilage does not have perichondrium and how is it supplied
- articulate cartilage at joints
- diffusion of metabolites from synovial joints
Types of cartilage
- hyaline
- elastic
- fibrocartilage
Characteristics and structure of hyaline
- glass like, homogenous cartilage
- no perichondrium at articular joints
- has type 2 collagen and aggrecan
- cells isolated in isogenous aggregates
Where is hyaline found in adults and young children
- large respiratory walls
- ventral part of ribs
- at joints
- in epiphyseal
-temporary skeletal structure
Matrix of cartilage structure and components and their functions
- 40% dry mass collagen 2 in hydrated ground substance
- aggrecan most abundant proteoglycans bound on hyalaronan
- basophilic due to sulfates gag’s
- chondronectin binds cells to ecm
Territorial and inter territorial matrix
-matrix immediately around isogenous groups with high conc of Gag’s
-region further from aggregates and in between territorial groups
Less gag’s and more collagen
Where are cells found in cartilage
Lacunae
Shape of chondroblasts and chondrocytes and where found
- elliptical with long axis parallel to surface and at peripheral of cartilage
- more rounded and found in isogenous aggregates embedded in cartilage
How many cells make a isogenous aggregates
Up to 8
How to cartilage cells metabolize and why
-anaerobic glycolysis due to low O2 conditions
What defines thickness of cartilage
-the limits of diffusion
How is secretion of gag’s accelerated
-somatotropin stimulates liver to release somatomedins which directly stimulate chondroblasts to accelerate more gag’s
Elastic cartilage structure and characteristics as function
- similar to hyaline cartilage but with abundance of elastic fibers
- yellow color of fresh cut elastic cartilage
- has perichondrium everywhere
-provides structural support to softer tissue
Where is elastic cartilage found
- ear and auditory canals
- upper respiratory tract
Fibrocartilage structure and characteristics
- no distinct perichondrium
- a mixture of hyaline and dense CT
- both collagen 1 and 2 present
- cells are aligned and singular in isogenous aggregates
- aggregates separated by dense collagen 1 and scattered fibroblast
Where is fibrocartilage found and function
- vertebrate disc
- pubic symphysis
-where tough cushioning is needed
Chondrogenisis
Mesenchyme in Embryonic CT starts to divide and differentiate producing a Tissue with condensed chondroblasts
- The cells begin to synthesize and secrete matrix and separate from each other as matrix grows and swells with water
- The chondroblasts start to divide and give rise to aggregates surrounded by territorial matrix
Lineage of cartilage
-embryonic mesenchyme
