Bone Physiology Flashcards
functions of bone
-supports body
-muscle attachment zone
-protects soft tissue
-product blood
hematopoiesis
producing blood cells in red bone marrow
epiphyseal line
the line given in a long bone after the epiphyseal plate has died (no more bone growth)
periosteum
the bone’s ‘skin’
bone types
-long
-short
-flat
-irregular
long bone
- longer than they are wide
- long shaft with two bulky ends or extremities
-primarily compact bone but may have a large amount of spongy bone at the ends or extremities - produce least amount of blood
short bone
-roughly cube shaped with vertical and horizontal dimensions approximately equal proportions
-primarily spongy bone covered by a thin layer of compact bone.
-include the bones of the wrist and ankle
-produce most blood
flat bone
-thin, flattened, and usually curved
-no bone marrow
-no internal cavity(ies)
irregular bone
-bones not characteristic of any other of the bones types (no long, flat, or short)
-primarily spongy bone that is covered with a thin layer of compact bone
-vary in structure and shape
what is the bone matrix made out of
-15% H2O, 30% collogen, 55% mineral salts
-Ca(PO4) and Ca(CO3)
why is Vitamin D so important for bones?
No Vitamin D = no Ca intake = no Ca for osteoblast = weak bones (less density)
lamellae
makes up osteons
concentric lamella
lamellae that make up the circle of the osteon
interstitual lamellae
lamellae that make up the ‘inbetween’ of the osteons
haversion canal
systems of blood vessels that travel through the bones
canlicula
where osteocytes ‘reach out’ to communicate with one another
bone cells
-osteoblasts
-osteoclasts
-osteocytes
-osteogenic cells
osteoblasts
-build bone cells
-become osteocytes with age
osteoclasts
-remove/reabsorb bone
-old white blood cells
osteocytes
-manage all other bone cells
-old osteoblasts
osteogenic cells
-‘baby’ bone cells
-become osteoblasts with age
types of fractures
simple
compound
compression
depression
comminuted
impact
spiral
greenstick
simple fracture
-only bone damaged
-little to no soft tissue damage
-complete break
-typically transverse
compound fracture
-fracture off axis
-open = through skin
-closed = not through skin
compression fracture
-crushing/crumbling of bone
-common in vertebrae
depression fracture
-crushing/indent/pushing force on bone
-common in the skull (cranium)
comminuted fracture
-3+ fragments of bone broken off
-requires hardware to heal correctly
impact fracture
-bones crush against one another
-think FOOSH
spiral fracture
-break caused by twisting force
-typically requires hardware to heal correctly
-oblique break
greenstick fracture
-incomplete fracture of immature bone
-only one side of bone broken
-IMMATURE BONE
steps of bone repair
1) hematoma formation
2) fibrocartilaginous callus formation (aka soft callus formation)
3) bony callus formation
4) bone remodeling
hematoma formation
-1st step in bone repair
-blood clot formed by broken blood vessels in the bone
-6-8 hrs after injury
-inflammation occurs
fibrocartilaginous callus formation
-2nd step in bone repair
-days after fracture occurs
-osteoblasts fixes the spongy bone
-fibroblast connect broken bones ends
-phagocytic cels clean away dead cells
bony callus formation
-3rd step in bone repair
-usually within week(s) after break
-bone ‘union’ occurs 6-8 weeks later
-new bone forms soft callus and then converts to a hard (bony) callus
bone remodeling
-4th step in bone repair
-8-10 years after break occurs
-bone is entirely replaced with new cells (like the fracture never happened)
