Cartilage Flashcards
What cells produce cartilage?
Chondroblasts
Is cartilage vascular or avascular?
Avascular
What are the three types of cartilage?
- Hyaline
- Elastic
- Fibrocartilage
What is different about cartilage compared to other CT?
Elastic, but firm
What type of fibers does cartilage contain?
Fine, collagen fibrils
Do not stain well
What type of fibers does elastic cartilage have?
Fine collagen
Elastic fibers
What type of fibers are present in fibrocartilage?How are these arranged?
Parallel collagen bundles
What is the most common type of cartilage?
Hyalin
How does hyaline cartilage appear?
Glassy, to whitish/bluish
Where is hyaline cartilage found?
- In places where is maintains a lumen (nose, larynx, trachea, bronchi)
- At articular surfaces of bones
- at epiphyseal plates of growing bones
What type of cartilage would you expect to find in: the nose
hyaline cartilage
What type of cartilage would you expect to find in: the larynx
hyaline cartilage
What type of cartilage would you expect to find in: trachea
hyaline cartilage
What type of collagen would you expect to find in: bronchi
hyaline cartilage
What type of cartilage would you expect to find in: the ventral ends of the ribs
hyaline cartilage
What type of cartilage would you expect to find in: shoulder, hip, elbow, knee
hyaline cartilage
What type of cartilage would you expect to find in: epiphiseal plates?
hyaline cartilage
What is histogenesis?
Growth of hyaline cartilage
What are condrification centers?
future cartilage sites
What type of cells form condrification centers?
Mesenchymal cells
What shape are mesenchymal cells?
Stellate, but turn into round
What cells synthesize the ECM? What type of cells give rise to this type?
Chondroblasts, which come from mesenchymal cells
What are lacunea?
“Bubbles” within the ECM formed by chondroblasts, where chondroblasts reside
What is the first step in synthesizeing the EMC of hyaline cartilage?
Mesenchymal cells retract their bodies from a stellate formation to a circular
What are chondrocytes?
Chondroblasts that have surrounded themselves with the ECM of hyaline cartilage
What are isogenous groups?
2-4 groups of cells that all spawned from a single cell, and reside in the same lacunae
What is interstitial growth?
When isogenous groups divide, synthesize more ECM, and cause the hyaline cartilage to grow
What is the perichondrium?
The membrane that surrounds ONLY hyaline and elastic cartilage
The perichondrium is derived from what cell type?
Mesenchyme
Fibroblasts spawn from what type of cells? What do they synthesize?
Spawn from mesenchyme.
Synthesize collagen
What are the two layers of the pericondrium?
Inner layer which is cellular
Outer layer which is fiberous (collagen I)
What is present in the outer layer of perichondrium?
Collagen I
fibroblasts
blood vessels
Nerves
What is present in the inner layer of the perichondrium?
Condrogenic cells (divide to form chondroblasts)
What are chondrogenic cells?
Cells that will eventually turn into chondroblasts
How does cartilage grow?
on the surface of an existing cartilage, known as appositional growth
What is appositional growth?
When a cell layer grows on top of old layers (pushing it outwards)
Does cartilage tissue contain blood vessels?
No
How does the inner cell layer get nutrition if there are no blood vessels?
Perichondrium supplies it, and since the inner cell layer is hydrated, is diffuses
How does the perichondirum keep the growth of the inner cell layer in check?
By how far diffusion of nutrients will go in the inner cell layer
What is the general function of the outer cell layer of the perichondrium? Inner?
Outer = protection Inner = growth
What are the two ways in which cartilage grows?
interstitially and appositionally
When does interstitial growth occur in hyaline cartilage (3)?
- during the early stages of cartilage formation
- in articular cartilage (which does not have a perichondrium)
- in epiphyseal plates
What is intersitial growth?
When cell growth occurs from within the cartilage
What is appositional growth?
Cell growth the occurs on the surface of cartilage?
Where does appositional growth take place?
In most cartilages
When does appositional growth occur in cartilage?
Throughout the lifespan of the cartilage
Interstitial growth occurs from what type of cells?
isogenous groups
What type of cell is responsible for appositional growth of cartilage?
Chondroblasts
True or false: there is no perichondrium at the ends of growth plates?
True
Chondrogenic cells arise from what type of cells?
Mesenchymal cells
Chondrogenic cells can differentiate into what two types of cells?
Chondroblasts (cartilage forming)
Osteoprogenitor cells (bone-forming cells)
Can chondrogenic cells synthesize cartilage?
No
Where are chondrogenic cells found?
Condrification centers
The deep layer of the perichondrium
What is the function of chondrocytes?
Maintain matrix
Chondroblasts function as what?
Forming the matrix and the fibers of cartilage
True or false: chondrocytes have a small nucleus, and a small or absent nucleolus?
False
What does the hyaline cartilage matrix contain?
Collagen II
proteoglycans
glyoproteins
ECF
Where is the ECF in the hyaline cartilage matrix
Hydrating the collagen proteoglycans
Is collagen stretchable?
No,
What are hyaluronan molecules?
hyluronic acid that forms the backbone onto which proteoglycans stick
What property does the interweaving of hyaluronan molecules supply the matrix?
Shock absorption / resilience
What percentage of water is located in the intercellular proteoglycan aggregates?
60-80%
What percentage of the cartilage volume is made up of the extracellular matrix?
95%
What forms a capsule around each of the cells in an isogenous group (4)?
Tyoe VI collagen, Hyaluronan, glycoproteins,
Sulfated proteoglycans
What is the stain affinity of the capsule that surrounds the isogenous groups?
Basophilic
What surrounds each group of isogenous cells? What is the difference between the composition of the capsular matrix, and this?
Territorial matrix
Same composition except for lower sulfated proteoglycans
What surrounds the territorial matrix? What is the composition if it?
Interterritorial matrix
Same composition of the territorial matrix, but more dilute
The cartilage matrix consists of what percentage of water that is bound to proteoglycans.
60 - 80%
Does hyaline cartilage have nerve fibers?
no
What happens to the hyaline cartilage as we age?
Calcifies
Where is elastic cartilage found (4)?
ear
auditory tubes
epiglottis
larynx
What are the two types of fibers present in elastic cartilage?
Collagen II
Elastic fibers
What is the color of elastic cartilage?
yellow
Where are elastic fibers found within the elastic cartilage?
Territorial matrix
Does elastic cartilage calcify with aging?
No
What function does fibrocartilage serve?
transition between dense connective tissue and hyaline cartilage
What is mostly present in the matrix of fibrocartilage?
Collagen I
Does fibrocartilage have a perichondrium?
No
What type of cartilage would you expect to find in: the intervertebral discs (the annulus fibrosus specifically)?
fibrocartilage
What type of cartilage would you expect to find in: the pubic symphysis?
fibrocartilage
What type of cartilage would you expect to find in: articular discs (e.g. TMJ)
fibrocartilage
What type of cartilage would you expect to find in: menisci of the knee joint?
fibrocartilage
What type of cartilage would you expect to find attached to bone?
fibrocartilage
How are the condrocytes arranged in fibrocartilage?
in rows, squeezed between collagen bundles
What are fibroblasts?
proteoglycan secreting cells found in the fibrocartilage. These turn into chondrocytes when surrounded by matrix
What is osteoarthritis?
The breakdown of hyaline cartilage at joints (d/t lower hydration of the GAGs causes fissures)
What is the protein that allows for chondroblasts and chondrocytes to stay connected to the ECM?
Fibronectin
What are the only two types of cartilage that have a perichondrium?
Hyaline and elastic. NOT FIBROUS
Chondrogenic cells can differentiate into what two cells?
chondroblasts and osteoprogenitor cells
Chondroblasts can differentiate from what two types of cells?
mesenchymal cells
Chondrogenic cells
Are chondroblats acidophilic or basophilic?
basophilic
True or false: chondrocytes can go back to being chondroblasts?
True
What is the function of fibronectin?
Allows chondroblasts and chondrocyte to adhere to the ECM