What is the function of cartilage in general?
Specialized connective tissue Provides resilient support Resists compressive forces Capability to regain shape and size Smooth, cushioned surface for articulating bones
What are the cells in cartilage called?
Embedded within extensive extracellular matrix (cartilage matrix)
What are the three components of cartilage matrix?
- Ground substance
- Noncollagenous multiadhesive glycoproteins
What gives mechanical stability to the ground substance?
What is the primary type of fiber found in the cartilage matrix?
Type II is predominant form
Collagen found at the periphery of the chondrocyte and facilitates the link between the chondrocyte and the cartilage matrix
Type VI Collagen
Stabilizes type II collagen by facilitating collagen fibril-proteoglycan interaction
Associated with hypertrophic regions in cartilage where it organizes collagen fibrils into a 3D lattice
Regulates type II collage fibril size
What is the predominant component of cartilage matrix?
The Ground Substance
Hydrated gel composed of water, ions and proteoglycans
What is the predominant proteoglycan monomer?
What are multimolecular proteoglycan aggregates?
Aggrecan monomers bound to a central hyaluronate backbone
Have dense negative charge -- keeps the aggregates expanded d/t repulsion, also water and sodium ions are attracted to hydrate the gel matrix
Small regulatory and structural proteins that influence interactions between chondrocytes and the ECM
Noncollagenous Multiadhesive Glycoproteins
What are some of the noncollagenous proteins?
What are the multiadhesive glycoproteins clinically valuable markers for?
Cartilage turnover and degeneration
What is the function of chondrocytes?
They produce and secrete the components of cartilage matrix.
Also secrete enzymes that can degrade cartilage matrix.
Maintain the integrity of the cartilage matrix
What is the function of chondroclasts? What are they derived from?
Multinucleated cells that degrade calcified cartilage
Derived from monocytes and are similar to osteoclasts
What are some hormones that increase synthesis of cartilage?
What are some hormones that decrease synthesis of cartilage?
What are cartilage elements often enclosed in?
What is the outer part of the perichondrium?
Fibrous connective tissue (primarily type I collagen) secreted by fibroblasts
Contains a capillary plexus, nerves and lymphatics
What is the inner part of the perichondrium?
Contains flattened chondrogenic cells that have the potential to become chondroblasts.
How are chondrocytes nourised?
Diffusion through the cartilage matrix
Do chondrocytes have a high or low metabolic rate?
High -- despite being surrounded by an avascaular matrix
What are the three main types of cartilage?
What is the most common type of cartilage? How does it appaear?
Bluish-white, glassy appearance
What surrounds the chondrocyte acting as a biochemical buffer between the cell and the territorial matrix?
Is a perichondrium present around hyaline cartilage elements?
What are two types of specialized hyaline cartilage?