H04: Cartilage Flashcards
State the 3 types of cartilage.
Hyaline cartilage, fibrocartilage & elastic cartilage.
What fibres make up hyaline cartilage?
Collagen type II
Which types of cartilages are surrounded by perichondrium?
Elastic & hyaline cartilage.
What is perichondrium?
Thick connective tissue
What is the function of perichondrium?
Growth & maintenance of cartilage
Reservoir for progenitor cells & collagen type I
Which types of cartilage are NOT surrounded by perichondrium?
Fibrocartilage & articular cartilage.
What makes elastic cartilage different from other types of cartilage?
Along with collagen fibres, it also has elastin fibres so it is more flexible.
What fibres make up fibrocartilage?
Collagen type I & II
What makes fibrocartilage different from other types of cartilage?
It is always associated with dense CT or hyaline cartilage.
What is the function of chondroblasts?
They produce ECM at the periphery of cartilage.
What is the function of chondrocytes?
They maintain the matrix by continuously turning it over.
Where are chondrocytes found?
Embedded in the matrix as clusters of 2-8 cells.
How is cartilage formed?
1) Mesenchymal cells go from star-shaped to round.
2) Cytoplasm of mesenchymal cells extend & they start cell division.
3) Rapid cell division = agglomeration of rounded cells.
4) Rounded cells differentiate into chondroblasts.
5) Chondroblasts produce ECM, become trapped in ECM & are pushed apart.
6) Isolated cells divide to form chondrocytes.
State what type of cartilage provides structure, where it is found and what is required functionally.
- Hyaline cartilage found in nose & embryonic skeleton, for relative rigidity.
- Elastic cartilage found in external ear, for flexibility.
- Fibrous cartilage found in invertebral discs, for rigidity
State what kind of cartilage provides support, where it is found and what is required functionally.
- Hyaline cartilage found in tracheal rings, for maintenance of airways
State what kind of cartilage provides growth, where it is found and what is required functionally.
Hyaline cartilage found in the embryonic skeleton and epiphyseal growth plates, for rapid growth
State what kind of cartilage provides flexibility, where it is found and what is required functionally.
Elastic cartilage found in the epiglottis and external ear, for firmness with flexibility
State what kind of cartilage serves as a model, where it is found and what is required functionally.
Hyaline cartilage found in long bone ossification for development of body shape before bone development
State what kind of cartilage is in joints, where it is found and what is required functionally.
- Hyaline cartilage, found in articulating joints for smoothness of movement & low friction + shock absorption. No perichondium
- Fibrous cartilage found in suture joints to resist stresses
How does cartilage increase in width?
By appositional growth
- Peripheral perichondrial cells differentiate to form chondroblasts that will produce ECM to increase cartilage mass around the edges.
How does cartilage grow bigger?
By interstitial growth
- Embedded cartilage by mitosis during early cartilage formation which increases cartilage mass from within.
How does cartilage repair itself?
1) Perichondrium is re-established.
2) Fibrous tissue fills the damaged areas & becomes calcified.
Which type of cartilage can’t be repaired and why?
Articular & fibrocartilage because they have no perichondrium.
How is slight wear of cartilage repaired?
By secretion of extra matrix.
How is extensive damage of cartilage repaired and what is the effect of this??
By production of fibrous tissue which results in a loss of smoothness.
How does age affect cartilage?
It cause mineralisation of cartilage, so nutrients can’t diffuse through the cartilage and chondrocytes die.
