Lecture 8- Cartilage Flashcards
What is cartilage?
Connective tissue
What are the types of cartilage?
- Hyaline
- Fibrocartilage
- Elastic
Where is hyaline cartilage found?
Articular cartilage, most joints
Where is fibrocartilage found?
pubic symphisis, vertebrae
Where is elastic cartilage found?
ear
What is the outer layer of cartilage called?
Perichondrium
Does the EC matrix in the perichondrium look the same as the ECM in the hyaline cartilage?
No. The perichondrium is dense CT with type I collagen. The ECM of hyaline cartilage is type II collagen with lots of ground substance forming a gel.
Why does the EC matrix in hyaline cartilage appear more purple?
Aggrecan and GAG containing negatively charged sulfates are basophilic. These mix with the type II collagen making the matrix appear purple.
What does the negative charge of the Glycoaminoglycans have an affinity for?
Water, making the matrix a gel like substance
What is the function of the type II collagen and the ground substance in hyaline cartilage?
- tensile strength
- ground substance makes it resistant to pressure
What types of cells are in the perichondrium and hyaline cartilage?
- fibroblasts
- chondrocyte in lacuna
Where are the fibroblasts found near cartilage?
perichondrium
Where are the chondrocytes found?
EC matrix of the hyaline cartilage. Usually surrounded by lacuna. The cells shrink when fixed and can become artifacts.
It takes a long time for damaged cartilage to repair itself. Why?
Cartilage is avascular. The blood supply is in the dense irregular connective tissue of the perichondrium.
Where do new chondrocytes and matrix come from?
1) fibroblast cells of perichonrium
2) differentiate into chonroblast
3) appositional growth
4) can divide and lay down matrix
5) interstitial growth
