CTO Cartilage and Bone Flashcards
Components of cartilage
Cells Ground substance Fibers (collagen, elastic)
Types of cells in cartilage
Chondroblasts, chondrocytes
What makes up ground substance in cartilage?
GAGs, hyaluronic acid, chondroitin sulfate, proteoglycans/glycoproteins (chodnronectin)
What fibers are in cartilage?
collagen, elastin
Functions of cartilage
(1) structural support for soft tissue (2) shock absorption in joints (3) reduce friction between joint surfaces (4) role in growth and development of long bones
Types of cartilage
(1) hyaline (2) elastic (3) fibrocartilage
Hyaline cartilage
Most common, fibers are type II collagen, forms temporary skeleton in embryo, epiphyseal plates(growth plates)
Location of hyaline cartilage
articular surfaces of moveable joints, ends of ribs, respiratory passages
Elastic cartilage
Type II collagen + elastic fibers, provides flexible support, yellow due to elastin
Location of elastic cartilage
auricle of the ear, eustachian/auditory tube, epiglottis
Fibrocartilage
Fibers are primarily type I, provides flexible strength, assoc. w/ dense connective tissue, resists compression and shearing
Location of fibrocartilage
Intervertebral and articular discs, knee menisci, pubic symphysis
Formation of cartilage
chondroblasts derived from mesenchymal cells
isogenous nest
when chondrocytes undergo mitosis, daughter cells in the same lacunae
perichondrium
layer of dense connective tissue at free edge of cartilage Not present in articular or fibrocartilage
Function of perichondrium
source of nutrition for cartilage (blood vessels), inner layer contains chondrogenic cells
Two types of cartilage growth
appositional, interstitial
Appositional
Type of cartilage growth: new cartilage at edge -> increased thickness of cartilage
Interstitial
Type of cartilage growth: chondrocytes replicate inside cartilage, secrete new matrix -> expand cartilage from within
What type of cartilage can’t grow by appositional growth?
Articular - b/c not covered with perichondrium –> can’t repair itself very well
Also fibrocartilage (also doe snot have perichondrium)
Osteoarthritis
Breakdown/loss of cartilage of articular surfaces of joints –> bone rubs against bone
Bone spurs
May develop in OA b/c irritated bone tries to repair itself