What are the three types of cartilage?
Hyalin
Fibrous
Elastic
What is the ground substance of cartilage made out of?
Chondroitin sulfate
Keratan sulfate
What makes up the matrix of collagen?
Fibers + ground substance
Hyalin and elastic cartilage develop from what?
Mesenchyme
Mesenachymal cells differentiate into what?
Chondroblasts
When chondroblasts become entrapped in lacunae, what are they termed?
Chondrocytes
From what is the perichondrium derived?
Mesenchymal cells surrounding the developing cartialge
What is the outer layer of the perichondrium made up of?
Fibroblasts
Mesenchymal cells
Where is the chondrogenic layer found?
In the inner layer of the perichondrium
What is the chondrogenic layer?
Where chondroblasts undergo mitosis to produce more chondroblasts
From what does fibrocartilage develop?
Dense connective tissue
What is appositional growth?
Growth only occurring on the surface
Appositional growth only allows for which direction of growth?
Width
In appositional growth, where are the new layers of cartilage laid down?
Around the perimeter of the existing cartilage
What will occur to appositional growth if the perichondrium is removed?
Appositional growth will cease
Appositional growth is dependent upon what?
The mitotic activity of the chondrogenic layer of the perichondrium
What is interstitial growth?
When new cartilage is added within existing cartilage
Interstitial growth increases what?
Length (specific for endochondral bone formation)
In interstitial growth, what is formed as a result of mitotic activity within lacunae?
Cell nests
In interstitial growth, continued secretion of matrix results in what?
The lacunae moving apart from one another
Does cartilage have a blood supply?
No
How to chondroblasts get nutrition?
Diffusion of tissue fluid through the matrix
Where does the tissue fluid that feeds the chondroblasts originate?
From blood vessels located outside the perichondrium
Invasion of cartilage by blood vessels is usually associated with what?
Calcification and death of the cartilage
What type of cartilage comprises the skeleton of the embryo?
Hyaline cartilage
What progressively replaces hyaline cartilage as we grow?
Bone
40% of the matrix of hyaline cartilage is what type of collagen?
Type II
In hyaline cartilage, the matrix appears ___.
Homogenous - can’t bee see with a light microscope
What makes up the amorphous ground substance of hyaline cartilage?
Chondroitin sulfate
Keratan sulfate
In hyaline cartilage, where are younger cells found? Older cells?
Small, flat-ish lacunae
Large, round lacunae
In hyaline cartilage, cell nests are present in areas where cells retain what?
The capability of mitosis
Is perichondrium present in hyaline cartilage?
Yes
Are there nerves and blood vessels in hyaline cartilage?
Nope
Where is hyaline cartilage usually found?
Ends of long bones Nose Larynx Trachea Bronchus Between ribs
How does elastic cartilage differ visibly from hyaline cartilage?
Fibers are noticeable in the matrix
Predominantly elastic fibers (few type II fibers)
Is there perichondrium in elastic cartilage?
Yes
Where is elastic cartilage found?
External ear (pinna) Epiglottis
Fibrocartilage is primarily made up of what?
Collagen fibers
How does fibrocartilage differ from hyaline and elastic cartilage?
Fewer lacunae per unit area
Develops from dense connective tissue (not mesenchymal)
No perichondrium
Where is fibrocartilage found?
Tendon insertions
Pubic symphysis
Intervertebral discs
