Cartilage Flashcards
cartilage
general
specialized CT
firm and pliable
contains cells that make fibers and ECM
types of cartilage
hyaline
elastic
fibrocartilage
hyaline cartilage
aka articular
made of fine collagen fibrils
white/blue/glossy/smooth appearance in fresh specimen
hyaline cartilage
function
reduce friction at moveable joints
shock absorber
shoulder, elbow, hand, hip, knee, foot
hyaline cartilage
locations
places that maintain a lumen/open space
articular surfaces of bones
epiphyseal plates of growing bones
open spaces
hyaline
respiratory passages (larynx, trachea, bronchi)
nasal cartilages (keep nostrils open)
articular surfaces
hyaline
moveable joints
thoracic cavity joints (costochrondral, sternocostal, synovial plane 2-7)
epiphyseal plates
for long bone growth
plates allow grow in length
start as all hyaline (hyaline cartilage model) > bone replaces cartilage
chondrogenesis
hyaline cartilage
- mesenchyme (embryonic CT)
- differentiate into chondroblasts (tight packed)
- produce ECM (spread apart)
- isogenous groups/clusters/bubbles of chondrocytes
perichondrium
CT capsule surrounds most hyaline
contains vessels and nerves
layers of perichondrium
outer fibrous layer: dense, collagenous CT, protects/supports, can see fibroblasts nuclei
inner cellular layer: allows cartilage growth/maintenance
fibroblasts make collagen
types of growth
interstitial: expansion from w/i cartilage (isogenous groups)
appositional: on surface of cartilage (inner perichondrium)
cartilage too thick?
cells furthest away from nutrients will die
interstitial growth
locations
chondrogenesis
articular cartilage
growth plates
none in articular bc no perichondrium
appositional growth
locations
in most cartilages
throughout lifespan of the cartilage
lacunae
hyaline
bubble that surrounds chondrocytes
hyaline matrix
composition
proteins (collagen II)
proteoglycan monomers (GAG’s)
hyaluronan molecules (w/ GAG’s attached)
ECM
hyaluronan + collagen fibrils = 3D mesh shock absorber
cartilage matrix
pericullular capsule around lacunae in chrondrocytes, protects vs. compression
intensely basophilic territorial matrix
lighter staining interterritorial
cartilage matrix
function
highly hydrated (95% ECM 5% cell)
permits diffusion of nutrients
hyaline cartilage
characteristics
avascular so nutrients/oxy diffuse thru ECM from close tissues
no nerve fibers otherwise would feel every joint movement
resists forces (tension, compression)
elastic cartilage
locations
ear, auditory tubes, epiglottis, larynx
elastic cartilage
characteristics
elastic fibers and collagen in fibrous perichondrium so bends easily
more/larger chondrocytes than hyaline
elastic fibers highly concentrated in territorial matrix
fibrocartilage
b/t dense CT and hyaline
dense collagen I alternate w/ rows of chondrocytes
collagen bundles parallel to stress
NO perichondrium bc so much collagen
fibrocartilage
locations
articular disk TMJ
intervertebral disks
pubic symphasis
cartilage WITHOUT perichondrium
fibrocartilage
articular cartilage
epiphyseal growth plates
osteoarthritis
clinical correlate
articular surface of bone degenerates = expose bone
GAG’s less hydrated with aging
pain from nerve fibers in bone exposed
osteoarthritis
symptoms
swelling, stiffness, reduce ROM in affected joints
most common type of arthritis
normal joint appearance
synovial cavity with synovial membrane b/t bones/cartilage
ankylosis
clinical correlate
from trauma via sport or string instrument
hyaline calcifies>dies>replaced w/bone >carpal bones fuse together = no movement bc no joints
rheumatoid arthritis
clinical correlate
autoimmune disease
autoantibodies attack synovial joints > hyaline damaged = disfigurement of joints + severe pain
