7.4 Flashcards
bone remodeling
ongoing replacement of old bone tissue with new bone tissue
osteoclasts
remove minerals and collagen
osteoblasts
deposit minerals and collagen
during resorpiton
osteoclasts release enzyme acids
enzymes
digest collagen and organic substances
acids
dissolve mineral salts
what does remodeling and growth depend on
all modeling and growth depends on growth factors
what is a fracture
and break in the bone
what happens when you get a fracture
blood supply is decreased slowing repair
why does cartilage take longer to heal
lack of blood supply
what happens 6-8 hours after an injury
forms a clot called fracture hematoma
-swelling and inflammation occur
osteoclasts
begin to remove damaged tissue (several weeks)
osteoprogenitors
invade the hematoma
fibroblasts
produce collagen fibers help connect broken bone ends
What do chondroblasts do
produce cartilage
how many weeks does it take to bridge bone
3
osteoblasts begin to
produce spongy bone trabeculae
-join living and dead portions of original bone
-lasts 3-4 months
-remodeling of new spongy bone
-dead bone fragments are resorbed by osteoclasts
-compact bone replaces spongy bone at edge of fracture
what are the different types of fracture (8)
-Partial (complete): break across the bone is incomplete
-complete: break across the bone is complete
-simple: bone does NOT break through the skin
-compund: Broken ends protrude through the skin
-Greenstick incomplete: Occurs on bend of bone (common in children)
-comminuted complete: fragments the bone (mult pieces/ surgeury car accidents)
-fissure incomplete: logitudinal break (more rare)
-oblique: diagonal/ slanted break
-spiral: caused by twisting bone excessively
-transverse: perpendicular break
