Bone Flashcards
a specialized connective tissue that supports the body, protect internal organs
bone
bone is composed of what?
calcified extracellular material, bone matrix, osteocytes, osteoblasts, and osteoclasts.
how many bones are in an adult’s body?
206
how many bones are in an infant’s body?
270
originates from the mesenchymal stem cells; synthesizes and secretes the organic components of the extracellular matrix
osteoblast
what does the osteoblast produce?
proteoglycans and osteonectin
very giant and multinucleated cells involved in removing calcified bone matrix; involved in bone remodeling
osteoclast
where are osteoclasts found?
interfaces involved in selective diffusion, absorption, and secretion
found in the cavitites between bone matrix layers with cytoplasmic processes in the small canaliculi that extend into the matrix
osteocytes
what are the inorganic compounds of bones?
calcium, phosphorus, magnesium, potassium, sodium
crystals that lie alongside collagen fibrils and are surrounded by amorphous ground substance
hydroxyapatite crystals
what are the organic compounds of bones?
collagen type I fibers and amorphous ground substance
where does the osteoprogenitor/osteogeonic cells populates?
inner cellular layer of periosteum
what does osteoprogenitor form?
more osteoprogenitor cells, osteoblasts, and chondrogenic cells
lines the endosteal and periosteal surfaces
osteoblast
synthesize organic components of bone matrix, regulate mineralization of bone matrix and activity of one resorption
osteoblast
what does osteoblast produce?
collagen type I, osteocalcin, multiadhesice glycoproteins, non collagenous bone matrix proteins (GAG, hyaluronan, chondroitin & keratan sulfate)
huge cells derived from the fusion of as many as 50 monocytes; concentrated in the endosteum
osteoclast
bone matrix is composed of?
collagen fibers and hydroxyapatite
gives the bone its hardness and ability to resist compression
bone matrix
consists of thick collar on end compact bones rounding the central marrow cavity
long bone
equal length and width
short bone
flat with two flat blades
flat bone
no definite morphology
irregular
can be found within the substance of tendon
sesamoid
irregular and random arrangement of cells and collagen; lightly calcified
woven bone
also known as newly calcified, immature bone, primary bone, and bundle bone
woven bone
remodeled from woven bone
lamellar bone
all normal regions of adult bone; also known as mature bone and secondary bone
lamellar bone
80% of all lamellar bone
compact bone
also known as cortical bone and is the thick, outer region of bones
compact bone
20% of all lamellar bone
cancellous bone
interconnected thin spicules or trabeculae covered by endosperm; aka spongy bone, trabecular bone, medullary bone
cancellous bone
inner region of bones adjacent to narrow cavities
cancellous bone
what are the two process where osteogenesis occurs?
intramembranous and endochondral ossification
intramembranous ossification is mostly used by?
flat bones
where does endochondral ossification occur?
hyaline cartilage
resting zone composed of typical hyaline cartilage
zone of reserve cartilage
hyaline cartilage will divide repeatedly and will be enlarged and secrete the type II collagen and different proteoglycans
proliferative zone
contains swollen, terminally differentiated chondrocytes
zone of hypertrophy
bone tissue first appears in this zone
zone of ossification
chondrocytes avout to undergo apoptosis and will eventually release matrix vesicles and osteocalcin
zone of calcified cartilage
places where bones meet or articulate allowing at least the potential for bending or movement
joints
joints that are very limited or no movement are classified collectively as?
synarthroses
freely mobile joints are called?
diarthroses
