pathophysiology of skeletal muscle disorders, deficiency disorders and metabolic bone disorders (wrapping up)

Question 1

what are contractures

Answer 1

chronic, progressive loss of joint ROM secondary to tightening of non-bony tissues
- hypertrophy or sclerosis of ligaments, musculature, tendons

Question 2

what are contractures typically due to

Answer 2

immobilization
can be congenital disease such as (DM or CP)
Arthritis
CNS injury
ulcers, burns
surgery/trauma

Question 3

how long does it take muscle fiber protein synthesis to decrease

Answer 3

first 6 hours of a joint being immobilized

Question 4

when does muscle fiber shortening occur after a joint is immobilized

Answer 4

first 24 hours

Question 5

what is the most common physical symptom associated with stress/anxiety

Answer 5

stress-induced muscle tension

Question 6

what are tension headaches due to

Answer 6

muscle spasms in the neck

Question 7

what is fibromyalgia

Answer 7

diffuse pain without the classic structural changes that cause discomfort (no inflammation or tissue damage) - disordered pain regulation

Question 8

what is the cause of fibromyalgia

Answer 8

genetic predisposition, serotonin or catecholamine signaling pathway, increase substance P in CSF, decreased grey matter overall

Question 9

what is myositis

Answer 9

disease process that result sin muscle inflammation - muscle fatigue and weakness

Question 10

what causes myositis

Answer 10

viral: typically influenza A&B or enteroviruses
Bacterial: pyomyositis - typically hematogenous spread
Parasitic: most commonly associated with trichinosis, cysticercosis, toxoplasmosis - associated with travel

Question 11

what can extreme viral myositis lead to

Answer 11

rhabdomyolysis or compartment syndrome

Question 12

what is polymyositis

Answer 12

immunite-mediatedd myopathy
most commonly affects proximal muscle groups and is symmetrical muscular weakness

Question 13

what is dermatomyositis

Answer 13

immune mediation myopathy
most commonly affects the proximal muscle groups, symmetrical muscular weakness and presents wtih skin involvement

Question 14

what is the skin involvement in dermatomyositis

Answer 14

gottron papules
heliotrope eruption
facial erythema
holster sign

Question 15

what is rhabdomyolysis

Answer 15

disease process in which muscle necrosis occurs leading to the release of intracelluar contents

Question 16

what is injured during rhabdomyolysis

Answer 16

myocytes and their membranes

Question 17

what is myoglobin

Answer 17

O2 binding protein (contains heme- why the urine will be + for blood) that stores it until needed for ATP and muscle contraction

Question 18

what are complications of rhabdomyolysis

Answer 18

acute kidney injury - secondary to renal tubular obstruction from heme casts
compartment syndrome - may be a secondary issue or cause rhabdo
disseminated intravascular coagulation- rare and may develop associated with release of thromboplastin

Question 19

what is the primary causes of phabdo

Answer 19

crush injury
alcohol
opiates
seizures
marathons/military basic training

Question 20

what is the presentation of rhabdo

Answer 20

myalgias
red/brown urine
malaise
fever
tachycardia
N/V

Question 21

what is ostomalacia

Answer 21

metabolic bone disease leading to ‘bone softening’
reduced bone mineralization that can occur at any age

Question 22

what is the presentation of osteomalacia

Answer 22

bone and muscle pain, increased frequency of fractures and fatigue

Question 23

what does osteomalacia result in

Answer 23

unmineralized osteoid

Question 24

what is ostoemalacia associated with

Answer 24

vitamin D deficiency, malabsorption, hypophophatemia, ETOH abuse, tumors and drugs

Question 25

what is Rickets

Answer 25

insufficient mineralziation of the growth plate congenital or aquired

Question 26

what is rickets associated with

Answer 26

inadequate calcium and or phosphate growth plate enlarges and disorganized

Question 27

what does rickets lead to

Answer 27

weakness and bowing of the bones - occurs prior to closure of the growth plates

Question 28

what is osteoporosis and osteopenia

Answer 28

low bone mass - continuum of disease

Question 29

what does osteoporosis and osteopenia lead to

Answer 29

bone fragility because of the low bone mass and micro-architectural disruption

Question 30

what are the deficiencies in osteoporosis/osteopenia

Answer 30

both nutritional supply as well as hormonal support will cause a decrease in bone integrity

Question 31

How does thyroid disorders lead to osteoporosis/osteopenia

Answer 31

PTH produces more calcium which increases osteoclast activity

Question 32

what are the causes of osteoporosis/osteopenia

Answer 32

failure to reach peak bone mass worsens throughout later years during times of bone mass genetic predisposition hormonal disorders poor nutrition tobacco use

Question 33

what is Paget's disease also known as

Answer 33

osteitis deformans

Question 34

what is pagets disease

Answer 34

idiopathic dysregulation of bone remodeling results in enlarged, deformed bone - thought to be a cellular abnormality or associated with viral infection such as RSV

Question 35

what does vitamin D deficiency lead to

Answer 35

hypocalcemia and or hypophosphatemia and may result in rickets aor osteomalacia

Question 36

what is Vitamin D

Answer 36

fat soluble vitamin that assists with the absorption of calcium, magnesium and phosphate and helps with homeostasis of bone metabolism

Question 37

how much vitamin D is absorbed through the skin

Answer 37

50-90%

Question 38

what does vitamin D deficiency result from

Answer 38

decrease dietary intake/absorption decreased sunlight absorption decrease endogenous synthesis increased liver breakdown

Question 39

what is neuromuscular junction channelopathies

Answer 39

disease process hallmarked by impaired neuromuscular transmission - deficiency of function between the nerve and muscle cell

Question 40

what are the causes of NMJ channelopathies

Answer 40

genetics toxic autoimmune disorders (myasthenia gravis, lamber-eaton syndrome)

Question 41

how do NMJ channelopathies present

Answer 41

with fatigue and weakness