cartilage Flashcards
What is hyaline cartilage?
- most common cartilage
- found on most non-articular surfaces such as the ends of ribs, nasal septum, lyarx, tracheal ring
- collage fibers are cross linked and loosely woven together
Where do you find elastic cartilage and how is it treated?
- not typically treated by PT
2. found in the exteranl ear, auditory canals, epiglottis, laryngeal cartilage, and walls of eustachian tubes
which is more dense elastic or hyaline cartilage
elastic
How is Fibrocartilage organized?
consists of alternating layers of hyaline cartilage and dense collagen fibers orientd in a directions of stress
Where do you typically find fibrocartilage?
intervertebral discs, articular cartilage, pubic symphysis, capsules, ligaments, enthesis
What is the functional cell of cartilage?
Chondrocytes
What is the root function of chonrocytes?
- produce and control ECM
2. immature chondrocytes know as chondroblasts produce GAG and type II collagen
What are the metabolic properties of cartilage?
- by nature cartilage is devoid of nerve supply, blood vessels and lymphatic vessels
- anaerobic metabolism is used by cartilage in its low oxygen environment
How does cartilage have both solid and flexible properties?
the ground substance of glycoprotiens imbibies water giving it viscoelastic properties
What is cartilage made of?
- half the dry weight is type II collagen
2. proteoglycans make up about 4-7% of the ECM
What are proteoglycans?
complex macromolecules comprised of a protein core joined to a long non-branching polysaccride such as GAG
How does cartilage resist high tensile loads?
since it is made of 65-80% water it is essentially noncompressable and is able to take high tensile loads
What are the layers of articular cartilage?
- superfiscial
- middle
- deep
- calcified
What is the superficial layer of articular cartilage?
- collagen in oriented parallel to joint surface
- rich in collagen
- low in proteoglycans
- high in tensile loads
What is the middle layer of articular cartilage?
- less organized collagen
2. greater proteoglycan content than the superficial layer
What is the deep layer of articular cartilage?
- highest concentration of proteoglycans
- collagen organized to resist shear
- compression improves in capacity for resisting shear
What is the calcified zone of articular cartilage?
- large content of apatite salt
- minimal blood supply
- transports nutrients to other layers
How is the metabolic rate of collagen regulated?
- hydrostatic pressures
- growth factor
- interleukins
- matrix make up
- electric fields
How is fluid imbibed into cartilage?
1donnan osmotic pressure- differences in intra and extra cellar ionic charge creates a magnetic effect
- electroastic repulsion forces- proteglycans have a negative charge creating metabolic movement
- entropic tendency of proteoglycans to gain volume
How are proteteoglycans produced?
- compression of cartilage triggers production
- the rough endoplasmic reticulum produces a protein core
- as the protein core leaves the RIR it is sulfated by the Golgi apparatus
- the sulfated protien core passes through the membrane and attaches to hylauronic acid
How does compression benefit from cartilage?
- triggers production of GAG
2. increase rate solutes move towards and away from cells deep within cartilage
How does joint gliding benefit cartilage?
gliding causes the synovial fluid to become less viscous which facilitates imbibition of the cartilage
How do you decrease synovial fluid viscosity?
- joint gliding
2. the fast the movement the less viscose the synovial fluid