Exam 2: Bone Flashcards
osteoblast
actively secrete matrix in one direction
osteocyte
trapped in matrix, cannot secrete
maintains matrix w/ mineralized calcium salts
Osteocytes are derived from…
mesenchymal cells
Ground substance in bone make-up
hydroxyapatite (mineral calcium salts)
Function of matrix in bone
weight-baring, resists bending
Compact bone
dense/cortical
thin, very strong
Cancellous bone
spongy/medullary/trabecular
spaces w/ bone marrow inside
Epiphysis
articular surface of bone (ends)
lined with hyaline cartilage
Physis / Epiphyseal Plate
site of growth
grows in length
Diaphysis
central part of bone
contains nutrient canal (brings in circulation)
Two Types of Histological Bone Preps
Ground Bone
Decalcified Bone
Ground Bone
dried | air trapped
osteons with lamellae and central canal
flattened lacunae | central vessels
Decalcified Bone
fixed & demineralized
H&E stain
perforating canal (circulation between osteons)
Canaliculi
canals with cell processes from one cell to another w/ gap junctions
Canaliculi function
nutrition between cells (transmit via gap junctions)
Lacunae
spaces in matrix that living cells occupy
Periosteum
dense collagenous connective sheath
Endosteum
inner lining of bone
What is in between the periosteum & endosteum of bone
precipitate of calcium salts
Lamellae
ring-like structures that make up osteon
Circular/central lamellae
osteonal lamellae
Periphery Lamellae
Outer circumferential
Lamellae on inner surface of bone
inner circumferential
old lamellae of prior osteons between osteons
interstitial lamellae