Exam #2 Chapter 6 Flashcards
during long bone growth what happens on the diaphyseal side?
cartilage is replaced by bone at the same rate
if pressure in bones causes electrial changes that increase activity of osteoblasts what does it mean if you have a broken bone and apply weight to it?
it can speed up the heeling process
what does PTH cause osteoblasts to release?
RANK ligand
what does circumferential lamellae do to the bone surface?
it makes it smooth
does increasing mechanical stress on bones increase or decrease osteoblast activity?
increases
what cell becomes more active when blood calcium levels are too high?
osteoblasts
what do blood vessels grow into during endochondral ossification?
the perichondrium
who does the acceleration of bone growth from reproductive organs happen sooner?
females
where are hairline fractures common?
in the skull
how is spongy bone arranged?
into trabeculae
what substance makes up a major portion of the bone?
hydroxyapatite
how much of the weight of bone do bone cells account for?
2%
what type of ossification forms the epiphysis of the clavicle?
endochonral
what does spongy bone contain?
trabeculae of bone oriented on lines of stress
what is the difference between intramembranous and endochondral ossification?
in intramembranous ossification, bone forms from preexisting connective tissue membranes and in endochondral ossification bone forms from a preexisting cartilage model
what type of cells can reabsorb bone?
osteoclasts
what is the epiphysis?
the part of the long bone that develops from a center of ossification distinct from that of the diaphysis
what is the process of events to create woven bone? (3) (COO)
1) Connective tissue membrane is formed
2) osteochondral progenitor cells become osteoblasts
3) osteoblasts produce woven bone
what does compact bone cover?
the spongy bone of the epiphysis
when someone is bedridden or paralyed (reduced stress on bones) what does that do for osteoblast activity?
it decreases, resulting in less bone density
where does cartilage grow in bone?
at the surface underneath the perichondrium or in the center
how is compact bone organized?
into osteons
what is the hollow space within the diaphysis of a long bone called?
the medullary cavity
what is used to produce bone in humans for the first time?
ossification