musculo-skeletal review Flashcards
what is the medullary cavity?
this is the area where hematopoiesis occurs within bone
compact bone has inner sections to it… what are they
they are made up of Rods called Haversian Canals / Osteons. the ring of the canal is called the lamellae. witin the lamellae exist lacunae which act as tiny lakes for osteocytes to sit in.
what is alkaline phosphate?
an enzyme which helps blast function
- high serum levels may indicate blast cancer
what is RANK ligand and osteoprotegrin (OPG)
both are produced by blast cells
RANK L –> binds clasts, activates NF-kB and activates the clast
OPG –> acts as decoy protein to sequester RANK L before they bind RANK receptors on clasts
opposite functions
What is estrogens role in bone?
estrogen promotes OPG release –> post-menopausal woman don’t produce estrogen and are at risk of osteopenia
what does PTH do? (3 mechanisms)
overall, PTH is released to increase Ca++ serum levels
- increases Ca+ reabsorption in kidneys
- decreases phosphate reabsorption in kidneys
- stimulates RANK ligand release from osteoblasts
what does vitamin D do (activated calcitriol via kidneys)?
vitamin D promotes GI uptake of BOTH calcium and and phosphate –> provides body with resources to build bone
note: vitamin D can also stimulate RANK ligand release (i.e. osteoclasts) but this occurs to allow Ca++ to be freed up and used for deposition somewhere else
what does cortisol do with bone?
it removes the matrix (collagen)
what are... comminuted segmented spiral greenstick impacted compression Colle's Pott's fractures?
comminuted –> broken into loose, messy pieces
segmented –> several fractures, clean pieces
spiral –> broken while twisting
greenstick –> bent bone with small brake (incomplete)
impacted –> bone hits other bone
compression –> bone collapses on self (osteoporosis)
Colle’s –> tip of wrist fracture
Pott’s –> tip of anke fracture
–> Pott = putt where your ankle is
crepitus is?
bone grating on bone
explain bone healing (5)
- development of hematoma in the periosteum (membrane that surrounds bone)
- granulation tissue - formation of new tissue after damage - fibrosis, angiogenesis, etc.
- pro callus - chondrocyte makes cartilage
- boney callus - osteoblasts make bone
- remodelling - 4 months of clast remodelling
what is non-union?
when two bones dont align properly after a break
what is reduction? what is traction and debridement?
reduction = to lead back the bones into original pieces –> done through casts
traction - stretch bone slightly to counter muscle spasms that interfere with reduction
debridement –> removal of foreign material (inflammation)
tendons vs ligaments
tendons –> bone to muscle, strain
ligaments –> bone to bone, sprain
what are subluxations and avulsions?
types of dislocations
subluxation = partial dislocation
avulsion = full ligament / tendon separation from bone
what is repetitive strain?
overuse injury of a LIGAMENT –> exception that ligaments are always ‘sprains’
carpel tunnel syndrome is an example of a repetitive strain
explain what and causes of…
kyphosis
lordosis
scoliosis
kyphosis –> increased convexity of back –> caused by TB or osteoporosis –> aka hunchback
lordosis –> increased concavity of back –> caused by frontal weight - pregnancy / obesity. aka sway back
scoliosis –> S curved back caused by
- structural problems with bone - congenital
- functional problems - nerve / muscle problems
in terms of location, small molecules, and progression how does normal RA differ from juvenile RA?
normal RA
- slow progression
- rheumatoid factor ab’s
- affects small joints first
Juvenile RA (20 yrs or younger)
- fast / acute progression
- ANA antibodies (anti-nuclear) –> NO RF found
- affects larger joints
explain the progression of RA starting with small reactions of RF with joint elements (6)
- RF reacts with joint elements
- synovitis
- pannus formation –> granulation tissue that covers the joint (actually makes problem worse)
- increased pannus causes cartilage erosion –> can lead to crepitus
- fibrosis laid down
- joint fixation
the last step of RA may be joint fixation –> aka ?
ankylosis
what is contracture?
when antagonist muscles have different effects on a joint and may pull it one way
explain swan neck and boutonniere
swan neck - most distal joint in finger is affected - bends tip of finger up
boutonnière –> bends thumb into a boot
what are RA nodules?
granuloma’s in RA patients –> not the same as pannus
what is uveitis, when does it occur?
uveitis is iris inflammation seen in juvenile RA
