Cartilage Flashcards
chondroblasts
cells that secrete cartilage matrix
chondrocytes
mature cartilage cells in lacunae; surrounded by and help maintain the ECM
cartilage matrix made up of:
fibers (mainly type II collagen) and ground substance (proteoglycans); can be territorial or interterritorial
3 Types of Cartilage
Hyaline, elastic and fibrocartilage
surrounded by perichondrium, type II collagen, located in articular cleavage, larynx, trachea, ribs
Hyaline
surrounded by perichondrium, type II collagen, founding external ear, epiglottis, and auditory tube
Elastic
Lacks a perichondrium, type I collagen, in vertebral discs, pubic symphysis, and TMJ
Fibrocartilage
Territorial Matrix
darker stains, surrounds the isogenous groups of 2-3 cells; high GAGs and decreased collagen
Interterritorial matrix
lighter staining, more collagen II and less proteoglycans; outside of the territorial matrix
dense, irregular CT with vascular supply in hyaline and elastic cartilage only; is the source of new cartilage cells during growth
perichondrium
fibrous layer of perichondrium
outer layer that produces type I collagen and elastin; transition from cartilage and surrounding CT
Chondrogenic layer of perichondrium
inner layer which differentiates into chondroblasts; secretes type II collagen
components of hyaline cartilage and elastic fibers within the matrix; allows for rebound; surrounded by perichondrium; stains dark black
Elastic cartilage
hyaline cartilage and dense regular CT; type I and II collagen, less matrix, and NO PERICHONDRIUM; aligned in rows and isogenous group; withstand compression and shearing forces
fibrocartilage
Appositional growth
forms new cartilage on top of existing cartilage; chondrogenic cells located within inner layer of perichondrium; make type I collagen; after growth is initiated chondroblasts secrete type II collagen and ground substance
Interstitial growth
occurs within the cartilage mass; chondrocytes divide within lacunae creating new isogenous groups; secrete more matrix; AVASCULAR
When does repair cartilage form?
perichondrium involvement; matrix is part hyaline and part fibrous, both I and II collagen; can stimulate bone growth
Cells that make up a synovial membrane
synoviocytes
Types A synoviocytes
macrophage-like synovial cells; phagocytic and contains lysosomes to eliminate debris caused by friction; regulates inflammatory events
Type B synoviocytes
Fibroblast-like synovial cells; produce synovial fluid and hyaluronate which combine; lubricates and nourishes the articular cartilage
collagen fibers run perpendicular to tissue surface and bend to gradually form an arc; layering
Articular cartilage
chondrocytes are small, flat, and parallel; collagen fibers run parallel to surface
Superficial zone
chondrocytes slightly larger and round; alone and in isogenous groups; take oblique course through the matrix
Intermediate zone
large chondrocytes form columns PERPENDICULAR to articulating surface; collagen fibers follow orientation of chondrocyte columns
Deep zone
Rests on underlying cortex of bone; matrix of calcified cartilage layer stains darker than other matrix layers
Calcified zone
