Cartilage Flashcards
Cartilage
semi-rigid connective tissue
Avascular and neural
Get nutrients from diffusion
Functions of cartilage
support framework of some organs
lines the articulating surfaces of bones
shock absorption
makes up the majority of fetal/immature skeleton
Matrix of cartilage
contains proteoglycans
Gags are mostly hyaluronic acid, chondroitin-4-sulfate and chondriotin-6-sulfate
has a lot of water which makes it a better shock absorber
Chondrocytes
are cartiligate cells
Precursor to cartilage are
chondroblasts and chondrogenic cells
In type 1 and type 2 cells you will see…
fibroblasts
Hyaline cartilage locations
Articular surfaces of long bones
costal cartilage
larynx, trachea, bronchi
Elastic cartilage
External ear, epiglottis, eustachian tube
Fibrocartilage
Pubic symphysis
TMJ
Intervertebral discs
Hyaline cartilage
Most common of the 3 types of cartilage
Involved in endochondral ossification
Collagen is type II
Matrix surrounding each chondrocyte is rich in GAGS
Hyaline cartilage matrix
collagen embedded in a gel of proteoglycans and glycoproteins
Proteoglycans associate with hyaluronic acid to form aggregates that interact with collagen
Water binds to GAGS and acts as a shock absorber
Hyaline cartilage perichondrium
Hyaline cartilage (except for articular cartilage of joints) is surrounded by a layer called perichondrium)
Contains fibroblasts and type I collagen
Layers of periochondrium
Outer fibrous layer - mostly fibroblasts and type 1 collagen
Inner chondrogenic layer- chondroblsats and chondrogenic cells
Chondroblasts become surrounded by matrix and become trapped in..
lacunae and when they do they are referred to as chondrocytes (mature cells)
Isogenous groups
group of up to 8 cells resulting from mitotic divisions of a single cell
Capsular matrix
matrix adjacent to a chondrocyte. Poor in collagen and rich in GAGS
Territorial matrix
matrix arround by isogenous groups; more basophilic
interterritorial matrix
matrix between isogenous groups; more acidophilic
Lacunae
spaces in matrix where chondrocytes are located
Elastic cartilage has..
a periochondrium
Chondrocytes, often in isogenous groups which are found in lacunae
type II collagen fibrils
Elastic cartilage found in
epiglottis, extern eat, eustachian tube
Fibrocartilage
Intermediate between dense connective tissue and hyaline cartilage
No periochondrium
Type II and type I collagen
Chondrocytes in their lacunae and found in parallel rows separated by type I collagen fibers
Cartilage development
mesenchyme -> mesenchymal cells proliferate and differentiate -> inner cells become chondrocytes, outer cells become perichondrium
Intersitiial growth
mitotic division of preexisting chondrocytes
Cartilage grows by stretching from inside
New matrix expands cartilage from within
