Bone Flashcards
What makes up the inner periosteum layer?
contains osteogenic cells and osteoblasts
Where are osteogenic cells found?
periodsteum and endosteum
what is unique about osteogenic cells?
when there is low oxygen tension - it can cause them to change into chondrogenic cells
what do osteoblasts look like?
they are cuboidal and secrete organic matrix
in lacunae they assume a flatten shape
they have cytoplasmic processes
what houses osteoclasts?
howships lacunae located on bone surface they are formed by osteolytic activities of the osteoclasts they house!
what are the 4 regions of osteoclast
ruffled border, vesicular region, clear zone, basal region
what is primary bone consist of and where is it found?
contains large amounts of osteocytes and irregular collagen has low mineral content found in suture lines, tendon insertions and tooth sockets
where are lamellae located?
diaphysis (shaft) - they are the layers that make up haversian canal - remember appositional growth
what does endosteum line
contains osteogeni cells and osteoblasts and lines marrow caviy, volkman’s canal and haversian canal
what are the zones of epiphyseal plate?
reserve cartilage, cell proliferation, cell maturation and hypertrophy, calcifying cartilage, provisional ossification
what happens with calcium deficiency?
ricketts in children (calcified bone) and osteomalacia in adults
why is vitamin D important?
ossification and hypervitaminosis of D = bone resoprtion
Vitamin A - what happens in extremes?
deficiency inhibits propor bone foramtion and growth
excessive amounts accelerate the ossification of dpi plates
what role does the parathyroid hormone play?
stim osteoclasts to reabsorb and release calcium – elevates blood calcium levels
may also activate osteoclasts to osteolysis
what does calcitonin do?
inhibits matrix resoption and prevents the release of calcium
