IV - Bone Flashcards
Bone Stores: Calcium
99%
Bone Stores: Phosphorus
85%
Bone Stores: Magnesium
65%
Unmineralized bone
osteoid
Most abundant bone cell
osteocyte
Bone resorption cell
osteoclast
Bone cell with PTH, vitamin D and estrogen receptors
osteoblast
Multinucleated bone cells derived from the pluripotent hematopoietic stem cells
osteoclast
Mononuclear cells that synthesize most of the protein in bone
osteoblast
Deposits new bone matrix and mineralizes it
osteoblast
Trabecular or Spongy Bone
cancellous
Compact Bone
cortical
Bone: less dense, softer, weaker, less stiff
cancellous
Bone: facilitates main functions
cortical
Bone: highly vascular, contains marrow
cancellous
Bone: 80% of weight of the skeleton
cortical
Bone: site of hematopoiesis
cancellous
Bone: affected by osteoporosis
cancellous
Resorbs bone
osteoclast
Bone: pluripotent mesenchymal stem cells
osteoprogenitor cells
Synthesize, transport and arrange bone matrix
osteoblast
Bone: derived from hematopoietic progenitor cells
osteoclast
Bone: ruffled borders along its membrane to increase cell surface area
osteoclast
Bone: detect mechanical forces and translate them into biological activities
osteocyte
Functional unit of compact bone
osteon/Haversian system
Carries blood vessels and nerves through the osteon
Haversian canal
“Little layer” of bone matrix between concentric rings of osteocytes
lamellae
Houses osteocytes
lacunae
Houses osteoclasts
Howship’s lacunae
Protoplasmic extensions from osteocytes by which maintenance of bone is performed
canaliculi
Connects one Haversian canal to another
Volkmann’s canal
Developing and growing bones, hard callus of bone fractures, immature/primary/bundle bone, newly calcified
woven bone
Remodeled from woven bone, adult bone, mature/secondary bone
lamellar bone
80% of lamellar bone, thick outer region beneath periosteum, cortical bone
compact bone
20% of lamellar bone, inner region, adjacent to marrow cavities, spongy/trabecullar/medullary bone
cancellous bone
Intramembranous Ossification
mesenchyme → osteoprogenitor cells → osteoblasts → osteoid
Endochondral Ossification
erosion of pre-existing hyaline cartilage by osteoblasts → osteoid
Type I collagen defect
Osteogenesis Imperfecta
Lack of GH
Pituitary Dwarfism
Excess GH in adolescents
Gigantism
Excess GH in adults
Acromegaly
Permanent flexion contracture of the hand at the wrist (claw-like deformity) commonly caused by a fracture in the elbow or upper arm
Volkmann’s Contracture
Artery occluded in Volkmann’s Contracture
brachial artery
Muscles affected in Volkmann’s Contracture
flexor digitorum profundus, flexor pollicis longus
Most common primary bone cancer
Osteosarcoma
Sun-burst appearance on x-ray
Osteosarcoma
Area of new subperiosteal bone that is created when a new lesion raises the periosteum away from the bone
Codman Triangle
