musculo-skeletal review

Question 1

what is the medullary cavity?

Answer 1

this is the area where hematopoiesis occurs within bone

Question 2

compact bone has inner sections to it… what are they

Answer 2

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.

Question 3

what is alkaline phosphate?

Answer 3

an enzyme which helps blast function

- high serum levels may indicate blast cancer

Question 4

what is RANK ligand and osteoprotegrin (OPG)

Answer 4

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

Question 5

What is estrogens role in bone?

Answer 5

estrogen promotes OPG release –> post-menopausal woman don’t produce estrogen and are at risk of osteopenia

Question 6

what does PTH do? (3 mechanisms)

Answer 6

overall, PTH is released to increase Ca++ serum levels

1. increases Ca+ reabsorption in kidneys
2. decreases phosphate reabsorption in kidneys
3. stimulates RANK ligand release from osteoblasts

Question 7

what does vitamin D do (activated calcitriol via kidneys)?

Answer 7

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

Question 8

what does cortisol do with bone?

Answer 8

it removes the matrix (collagen)

Question 9

what are...
comminuted 
segmented 
spiral
greenstick
impacted 
compression 
Colle's 
Pott's 
fractures?

Answer 9

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

Question 10

crepitus is?

Answer 10

bone grating on bone

Question 11

explain bone healing (5)

Answer 11

1. development of hematoma in the periosteum (membrane that surrounds bone)
2. granulation tissue - formation of new tissue after damage - fibrosis, angiogenesis, etc.
3. pro callus - chondrocyte makes cartilage
4. boney callus - osteoblasts make bone
5. remodelling - 4 months of clast remodelling

Question 12

what is non-union?

Answer 12

when two bones dont align properly after a break

Question 13

what is reduction? what is traction and debridement?

Answer 13

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)

Question 14

tendons vs ligaments

Answer 14

tendons –> bone to muscle, strain

ligaments –> bone to bone, sprain

Question 15

what are subluxations and avulsions?

Answer 15

types of dislocations

subluxation = partial dislocation

avulsion = full ligament / tendon separation from bone

Question 16

what is repetitive strain?

Answer 16

overuse injury of a LIGAMENT –> exception that ligaments are always ‘sprains’

carpel tunnel syndrome is an example of a repetitive strain

Question 17

explain what and causes of…
kyphosis
lordosis
scoliosis

Answer 17

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

Question 18

in terms of location, small molecules, and progression how does normal RA differ from juvenile RA?

Answer 18

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

Question 19

explain the progression of RA starting with small reactions of RF with joint elements (6)

Answer 19

1. RF reacts with joint elements
2. synovitis
3. pannus formation –> granulation tissue that covers the joint (actually makes problem worse)
4. increased pannus causes cartilage erosion –> can lead to crepitus
5. fibrosis laid down
6. joint fixation

Question 20

the last step of RA may be joint fixation –> aka ?

Answer 20

ankylosis

Question 21

what is contracture?

Answer 21

when antagonist muscles have different effects on a joint and may pull it one way

Question 22

explain swan neck and boutonniere

Answer 22

swan neck - most distal joint in finger is affected - bends tip of finger up

boutonnière –> bends thumb into a boot

Question 23

what are RA nodules?

Answer 23

granuloma’s in RA patients –> not the same as pannus

Question 24

what is uveitis, when does it occur?

Answer 24

uveitis is iris inflammation seen in juvenile RA

Question 25

what are tophi?

Answer 25

the swelling’s seen in gout due to uric acid buildup

Question 26

what is xanthine oxidase?

Answer 26

converts purine to uric acid

Question 27

what does allopurinol do?

Answer 27

prevents xanthine (i.e. purine) from being converted to uric acid by xanthine oxidase –> xanthine itself can be excreted.

Question 28

what are osteophytes?

Answer 28

bony spurs that develop in osteoarthritis due to subchondral bone grating

Question 29

what are Heberden’s nodes and Bouchard’s nodes?

Answer 29

Heberden –> distal phalnyx node, last finger joint swelling

Bouchard’s –> proximal (B as in bottom) phalnyx node.

Question 30

t or f
primary osteoperosis: post-menopause and senile
secondary: hyperparathyrodism, Cushing’s syndrome, and malabsorption.

Answer 30

true