Cartilage Flashcards
Two methods for growth in cartilage?
Appositional Growth & Interstitial Growth
Interstitial Growth
Growth by internal expansion; proliferation of chondrocytes and formation of isogenous groups
Appositional Growth
Growth by addition to existing surface; generation of new chondroblasts
Major two cells in cartilage?
Chondroblasts & chondrocytes
Extracellular Matrix makeup?
Makes up 95% of cartilage.
Rich in glycosaminoglycans & proteoglycans.
Allows for withstanding mechanical forces; very resilient
Three types of cartilage?
Hyaline Cartilage
Elastic Cartilage
Fibrocartilage
Hyaline Cartilage: ECM composition and perichondrium?
75% water, proteoglycans, hyaluronic acid, type II collagen
Perichondrium: present (with few exceptions)
Hyaline Cartilage: location?
Articulate surfaces, nose, larynx, tracheal rings, epiphyseal plates, fetal bone models
Hyaline Cartilage: appearence?
Dissection: Bluish white and translucent
Histo: matrix is generally basophilic; in routine staining, collagen fibers are indiscernible
Which type of cell can add extracellular matrix?
Both chondrocytes (interstitial growth) and chondroblasts (appositional growth).
Isogenous groups Indicate what in a histo slide?
Indicates interstitial growth.
Territorial matrix vs interterritorial matrix?
Territorial: heavy purple close to cells; more GAGs less collagen
Interterritorial: light purple/pink between cells; more collagen less GAGs
Elastic Cartilage: ECM composition and perichondrium?
Essentially the same as hyaline cartilage with the addition of elastic fibers
Perichondrium present
Elastic Cartilage: location?
Auricle, auditory canal, auditory tube, epiglottis
Elastic Cartilage: appearance?
Dissection: yellowish color
Histo: with special staining, elastic fibers are prominent between chondrocytes and lacunae
Special characteristics of Elastic cartilage in epiglottis?
With age, cartilage shrinks and is replaced with adipose cells.
Elastic vs hyaline cartilage?
More chondrocytes in elastic cartilage than hyaline.
However, less isogenous groups in elastic cartilage.
Fibrocartilage: ECM and perichondrium?
Type I collagen, less proteoglycans than other cartilages
Perichondrium: absent
Fibrocartilage: location and why?
Places with lots of pulling forces.
Good intermediate between dense connective tissue and cartilage.
Intervertebral discs, pubic symphysis, major tendon-bone anchorages
Fibrocartilage: appearance?
Histo: chondrocytes arranged in long rows separated by coarse collagen fibers; matrix is more acidophilic
