Lab 4: Bone Flashcards
describe classifications of bone
compact vs cancellous
lamellar vs woven
what is difference between compact and cancellous bone
compact is compact and more uniform
cancellous is spongy bone - looks porous
what is difference between lamellar and woven bone
lamellar is organized
woven is disorganized
describe lamellar bone
arranged in sheets
80% within compact bone
20% within spongy bone
describe woven bone
arranged randomly
growing and developing bones
what type of collagen is in bone
collagen type 1
name cells of bone
osteoblasts
osteocytes
osteoclasts
describe osteoblasts
cuboidal
eccentrically located nucleus
describe osteocytes
most abundant
appear flattened
describe osteoclasts
large multi nucleated cells
function in reabsorption of bone
name the important parts of bone
collagen type 1
cells
endosteum/periosteum
inner/outer circumferential systems (lamaellae)
haversian systems/canals
name parts of long bone
diaphysis
epiphyses
describe diaphysis
diaphysis = compact bone surrounding marrow cavity
describe epiphyses
epiphyses = spongy bone within compact bone and cartilage on the joint surfaces
what is epiphyseal plate
disc of cartilage that grows during childhoos
what is epiphyseal line
remnant of epiphyseal plate
describe periosteum of epiphyseal plate (2 layers)
outer fibrous layer of dense irregular ct
inner osteogenic layer containing primitive stem cells
what is a haversian system aka
osteon
what is compact lamellar bone
mature bone
describe center of compact lamellar bone
marrow cavity
made by endosteum
composed of osteoblasts
what does endosteum produce (compact lamellar bone)
inner circumferential lamellae
concentric to bone
describe exterior of compact lamellar bone
periosteum
describe periosteum of compact lamellar bone (layers)
fibrous layer
osteogenic layer
what does osteogenic layer produce (compact lamellar bone)
outer circumferential lamellae
concentric to bone
what are in between inner and outer circumferential lamellae
round haversian systems
what is in center of each haversian system (compact lamellar bone)
haversian canal
run lenght of long bone
joined perpendicularly by Volkmann canals
what delineates haversian systems (compact lamellar bone)
cementing lines
what are inbetween haversian systems (compact lamellar bone)
Interstitial systems
describe growth of long bones
longitudinal
first starts off with cartilage and mineralized cartilage matrix –> grows more and eventually bone growth
name the 5 zones of the epiphyseal plate
zone of resting cartilage
zone of proliferation
zone of hypertrophy
zone of cell death
zone of mixed spicules
describe zone of resting cartilage (layers of epiphyseal plate)
inactive chondrocytes
ecm = hyaline cartilage (collagen type 2)
describe zone of proliferation (layers of epiphyseal plate)
dividing chondrocytes
appear like stack of coins
cells actively divide to form isogenic groups
describe zone of hypertrophy (layers of epiphyseal plate)
swelling chondrocytes
cells become hypertrophic
cartilage in between isogenic groups is calcified
describe zone of cell death (layers of epiphyseal plate)
dying chondrocytes
cells die
can be noticed due to irregular nuclei and lacunae without cells visible
describe zone of mixed spicules (layers of epiphyseal plate)
no chondrocytes (eliminated in cell death layer) - some bone cells
calcified cartilage surrounded by bone - mixed
any cells surrounded by matrix = osteocytes
describe what happens to bone (secrete/breakdown) in mixed spicules layer of epiphyseal plates
bone is secreted by osteoblasts found at surface - bone here is woven
bone may be reabsorbed by osteoclasts or become anchored to side of the current bone
