Cartilage Flashcards
What are 3 components of cartilage?
Cells
Fibers
ECM
Why is cartilage classified as a specialized connective tissue?
unique physical characteristics: firm but pliable
What are chondroblasts?
cartilage-forming cells
What do chondroblasts produce?
Molecules of ECM (proteins, proteoglycans, and glycosaminoglycans) AND fibers embedded in matrix
When does a chondroblast become a chondrocyte?
when the chondroblast becomes trapped in the matrix it has produced, it is called a chondrocyte
Does cartilage have its own blood vessels or lymphatic cessels?
NO
Cartilage is avascular
*relies on diffusion of nutrients from surrounding tissues for nourishment
*also lacks nerve fibers
What are the three types of cartilage? (based on fiber type)
Hyaline
Elastic
Fibrocartilage
Why does Hyaline look glassy?
It contains fine collagen fibrils that are invisible with routine staining, thus the cartilage looks glassy
What contributes to the elastic property of elastic cartilage?
Elastic fibers
-It also contains fine collagen fibrils
What gives fibrocartilage its tensile strength?
Prominent parallel collagen bundles
What is the most common type of cartilage?
Hyaline
What is the appearance of hyaline cartilage in its fresh state?
Glassy, whitish-blue
Where is hyaline cartilage located? (3 places)
1) In places where it maintains a lumen/ space open [semi-flexible support]
2) At articular surfaces of bones
3) At epiphyseal “growth” plates of growing bones
What are chondrification centers and from what do they form?
Chondrification centers are future cartilage sites
Mesenchymal cells [star-shaped] retract their cell processes and become round-shaped cells
What do chrondroblasts do and from what do they form?
Chondroblasts synthesize ECM
Mesenchymal cells differentiate into chrondroblasts
What are lacunae?
“bubbles” within the matrix which contain trapped chondroblasts/chondrocytes
Tell me about isogenous groups
Chondrocytes divide to form genetically uniform progeny in isogenous groups
These new cells will synthesize ECM and become isolated from each other
Who is responsible for interstitial growth of cartilage?
chondrocytes
Where do fibroblasts come from?
During development, mesenchymal cells surrounding the cartilage differentiate into fibroblasts
What do fibroblasts form?
Dense collagenous connective tissue, the FIBROUS outer layer of the perichondrium
What is the perichondrium?
Connective tissue capsule that covers ONLY hyaline and elastic cartilage
What are the layers of the perichondrium? (2)
1) Outer fibrous layer
2) Inner cellular layer
What are the functions of the perichondrium?
The perichondrium is protective, supportive, and permits cartilage growth and maintenance
What does the outer fibrous layer of the perichondrium consist of?
Dense collagenous connective tissue with type I collagen, fibroblasts, blood vessels, and nerves