MSK 01 - Cartilage Flashcards
What substances make up the majority of cartilage? Give percentages
95% ECM (40% of which is collagen fibrils)
5% chondrocytes
What is the major component of cartilage ground substance?
GAGs
Describe cartilage ECM pliability
It is solid and firm but still pliable
What are the major functions of cartilage?
Hyaline Cartilage
Elastic Cartilage
FIbrocartilage
What are the locations of hyaline cartilage in the body?
What are hyaline cartilage cells called? What do these cells arise from?
What are the primary components of hyaline cartilage ECM?
Type-II collagen
GAGs
Glycoprotein
What is a perichondrium? How many layers does it have? Where is it found?
What type of cartilage has no perichondrium?
Cartialge found at articular surfaces
All fibrocartilage
What do the two layers of the perichondrium contain?
Is the cartilage matrix vascularized?
No
How does a cartilage matrix get its nutrients?
Nutrients are supplied by the vessels of the perichondrium by diffusion
What are chondroblasts? What do they do? Where do they come from? Where are they located and how are they situated?
Chondroblasts are ovoid cartilage matrix cells that synthesize cartilage matrix. They arise from chondrogenic cells and are situated just below the chondrogenic layer of the perichondrium so that their longitudinal axes lie parallel to the cartilage surface.
What is a lacunae?
The space occupied by a chondroblast
Facts to know about chondrocytes
- Mature chondroblasts located deeper in the cartilage matrix
- Spherical in shape
- They divide by mitosis to form 4-8 chondrocytes in a group called an isogenous group or cell nest
Isogenous group or Cell nest
What are the notable featurs of a chondrocyte as seen on TEM?
Chondrocyte
How did hyaline cartilage get its name?
About 15% of hyaline cartilage matrix is type-II collagen. Collagen fibrils are not readily visible in light micrographs due to possessing the same refractive index as ground substance. This gives a glassy appearance to the cartilage. Hyaline means glassy appearance
Facts to know about capsular matrix
That dark ring around the chondrocyte is capsular matrix
What is territorial matrix?
Matrix found around isogenous groups
What is interterritorial matrix?
Matrix in-between isogenous groups
What is the importance of the sulphate groups on the GAGs of cartilage?
What provides the majority of the strength that cartilage has?
The proteoglycans
What are the two types of growth seen in hyaline cartilage?
Appositional
Interstitial
What is appositional cartilage growth
What is interstitial cartilage growth?
What influences the growth rate of cartilage?
Discuss the regenerative properties of hyaline cartilage
Hyaline cartilage regenerates very poorly and the perichondrium forms scar tissue
Discuss the calcification of hyaline cartilage
It can get calcified in old age to the point that it is almost like bone
What are the 4 major regions of articular cartilage?
Were is elastic cartilage located in the body?
What types of substances and cells are present in elastic cartilage? What do these cells arise from?
Discuss the growth, degeneration, and calcification of elastic cartilage.
Perichondrium
Chondroblast
Elastic fibers
Chondrocyte
What is the major function of elastic cartilage?
To offer support and flexibility
Compare and contrast the hyaline and elastic cartilage matrices.
They are identical except that elastic cartilage matrix also has elastic fibers in it that give it a yellowish color
Where is fibrocartilage located in the human body?
Elastic Cartilage
Fibrocartilage
What types of cells and substances are present in fibrocartilage? What do these cells arise from?
What type of growth can occur within fibrocartilage?
Only interstitial, due to there being no perichondrium
Is fibrocartilage ever found alone?
No, it is always found in conjunction with hyaline cartilage and other fibrous tissues
Discuss the orientation of the components of fibrocartilage.
