Cartilage and bone Flashcards
what fetal cells does cartilage and bone differentiate
mesenchyme cells
what are the three cells active in the matrix
fibroblast
chondroblast
osteoblast
what are the three resting cells
fibrocyte
chondrocyte
osteocyte
where do resting cells reside
lacunae
what do fibroblasts do
produce collagen
what do chondroblasts do
produce cartilage
what do osteoblasts do
produce bone
what do osteoclasts do
breakdown bown
what is cartilage
firm extracellular chondrin matrix
sulphated mucopolysaccharide gel intermeshed with type II collagen fibres
no nerves, rarely any blood vessels
often surrounded by the perichondrium
what does the fibres and gel resist
fibres resist tension
gel resist compression
what is collagen laid down by
chondroblasts
what are the four types of cartilage
Hyaline skeletal
elastic skeletal
fibrocartilage
articular cartilage
hyaline skeletal
simplest, may mineralise in old age
found upper respiratory tract, ventral ribs
elastic skeletal
contains elastin fibres
found external ear, upper respiratory tract
Fibrocartilage
alternating layers of hyaline cartilage and collagen
found: intervertebral discs, symphyses, scuta, labra, menisci, discs
Articular cartilage
complex, partly fibrous, partly hyaline form
what is the precursor of bone development
hyaline skeletal
Functions of bone
compression/resistive structures - struts, levers
protection (cranium protecting brain, ribs protecting lungs/heart)
Elastic potential energy store
Acoustic (middle ear ossicles)
Display or combat (antlers)
Blood cell production in bone marrow
mineral store
what is the matrix (osteoid) composed off
one third by weight type I collagen
two thirds by weight hydroxyapatite with absorbed calcium carbonate (3 salts of calcium)
What do osteoblasts do
make bone
may live as long as the animal
What do osteoclasts do
break bone
myeloid blood cell derived
multinucleated
large cells (lots stuck together)
short lived
how is bone formation/destruction controlled
hormonally
by parathyroid hormone, calcitonin, Vitamin D
Classification of bones by location
axial and appendicular
cranial and postcranial
Classification of bones by morphology (shape)
long (humerus)
short (carpals)
Flat (scapula, skull)
irregular (vertebrae, skull)
sesamoids (patella, in tendons)
