Crutches–damage which nerve
radial nerve
Weakness in forearm, wrist, and finger extensors caused by
radial nerve damage (wrist drop)
Cochicine tox
GI irritation, agranulocytosis
–inhibits microtubules, affects rapidly growing cells
contraindications to NSAIDs
renal failure
peptic ulcer dz
elderly peeps
Ankylosing spondylitis–RF elevated?
NO
Sx of ank spon
- peripheral enthesitis (insertion of tendon to bone)
- -esp at achilles - Enthesitis of castovertebral junctions–hypoventilation
- -check chest expansion - aortic regurg
- uveitis
First/2nd/3rd line acute therapy for gout
- ibuprofen
- colchicine (if cannot take NSAIDs)
- glucocorticoids (if cannot take NSAIDs)
A band in sarcomere
same length
H band
Only mysoin
I band
only actin
How do you stain for muscle cells?
Actin, caldesmon, desmin
myasthenia gravis: which part of the NMJ is affected?
End motor plate potential decreased. Binding of antibody causes receptor internalization and fewer # of receptors
Perifascicular muscle inflammation
dermatomyositis
Anterior should dislocations will hurt which nerve?
axillary
What does axillary nerve innervate?
deltoid/teres minor with sensory innervation to the skin over the deltoid
Humeral midshaft fracture with swelling and ecchymoses of arm will damage which nerve
radial nerve
Describe pathophysiology of muscle repolarization/relaxation
- L-type calcium channels.
- activates (Ryanodine receptors) in junctional SR - Calcium-induced Calcium Release (CICR).
- myofibrils to contract.
- reuptake of calcium into SR stores
- calcium efflux out of the cell via Sodium-Calcium Exchanger (NCX; ~20%) and via sarcolemmal calcium pump (Ca2+-ATPase).
Ryanodine receptors
When calcium enters cell through voltage gated Cachannels, ryanodine receptors allow release of calcium from the SR
Calmodulin
Activates Ca-ATPase which pumps Ca out of the cell. Also helps to repolarize muscle cell after contraction, although indirectly
typical presentation of reactive arthritis
urethritis, conjunctivitis, arthritis of knees, ankles, and feet of young men
achondroplasia
impaired cartilage proliferation in the growth plate. Short extremities with normal sized head and chest (dwarfts)
–Problem with endochonral, not membranous bone formation
mutation achondroplasia
activating mutation in FGFR3
Inheritance of achondroplasia
auto dom
most mutations are sporadic tho
osteogenesis imperfecta defect
collagen type I
osteogenesis imperfecta inheritance
autosomal dominant
OI presentation
fractures, blue sclera, and hearing loss. (bones of hearing fracture)
Why do OI pts have blue sclera?
exposure of the choroidal veins
osteopetrosis
abnormally thick heavy bone that fractures. Inherited defect of bone resorption
defect in osteopetrosis
carbonic anhydrase II. Creates acidic environment needed to leech Ca from bone
presentation of osteopetrosis
anemia, thrombocytopenia, leukopenia (replaces medulla of bone).
- -hydrocephalus (bone builds up in skull) with hearing problems
- -renal tubular acidosis (carbonic anhyrase deficiency)
Tx: osteopetrosis
bone marrow tranplant
pidgeon breast deformity, frontal bossing, rachitic rosary, and bowing of legs
Rickets
alkaline phosphatase
osteoblast activation. Need alkaline environment to add calcium to bone
Lab findings in osteomalacia
Low serum Ca, low phosphate, increased PTH and alkaline phosphatase
What protects against weight loss after age 30?
Diet
exercise
estrogen
osteoporosis labs
`NORMAL LABS
What is contraindicated in osteoporosis?
Glucocorticoids–these increase bone loss
Paget disease of bone-pathophys
osteoclast goes rogue and starts eating up bone unregulated by blasts. Blast compensates by laying down bone improperly as fast as possible. then osteoclast burns out
Involves ONLY one or two bones!! not systemic
histology of paget’s disease
mosaic pattern of lamellar bone. MOSAIC=bone not fused. Haphazard instead of concentric cement lines
bone pain, increased hat size, lion-like faces and hearing loss in age 60
paget’s disease of the bone
lab finding in paget’s disease of the bone
elevated alkaline phosphatase. EVERYTHING ELSE (including serum calcium) is normal
treatment for paget’s
calcitonin and bisphosphonates
complications of paget’s disease
high output cardiac failure
osteosarcoma
osteomyelitis in kids
metaphysis
osteomyelitis in adults
epiphysis
osteomyelitis in IV drug abuser
pseudomonas
osteomyelitis in dog/cat scratch
pasteurella
vertebral osteomyelitis
TB
osteoma
benign tumor in facial bone. associated with gardner’s syndrome
osteoid osteoma
benign tumor of osteoblasts in cortex of long bones in young adults
bone pain that resolves with aspirin. X ray shows a bony mass with a radiolucent core
osteoid osteoma
osteoblastoma vs osteoid osteoma
over 2 cm
arises in vertebra
bone pane that does NOT respond to aspirin
most common benign tumor of bone
osteochondroma
sticks out from bone surface, continues from medullary
osteosarcoma
proliferation of osteoblasts
age of osteosarcoma pts
teenagers and elderly
High risk for osteosarcoma in teenagers
familial retinoblastoma
High risk for osteosarcoma in elderly
paget’s disease of the bone. radiation
Where do you usually see osteosarcoma?
metaphysis of long bones, distal femur or proximal tibia
X ray finding in osteosarcoma
Codman’s angle: raising of periosteum.
histology of osteosarcoma
pleomorphic cells producing osteoid
soap bubble appearance of bone on X-ray
giant cell tumor
epiphyseal tumor
giant cell tumor
ewing sarcoma derived from
neuroectoderm
ewing grows in
medullary cavity
Onion skin appearance on X-ray
ewing sarcoma
ewing histology
Small round blue cells with an 11,22 translocation
chondroma shows up in
medulla of small bones of hands and feet
chondrosarcoma shows up in
medulla of pelvis or central skeleton
osteolytic lesions
metastatic tumors. most common
prostatic carcinoma in bone
osteoblastic lesion (bone sclerosis)
RA associated with
HLA-DR4
pannus
granulation tissue in synovium. destroys cartilage and ankylosis (fusion) of joints.
complications of RA
anemia of chronic disease
secondary amyloidosis
complication of ank spon
aortitis–>aortic regurg
sausage finger/toe
psoriatic arthritis
Reiter’s occurs after
chalmydia infection
infectious arthritis
S aureus
gonorrhea
Causes of secondary gout
Leukemia
Lesch-Nyhan
Renal insufficiency
negatively birefringent crystals
Yellow when parallel and under polarized light
psuedogout
rhomboid shaped crystals with weak positive birefringence
dermatomyositis associated with
underlying carcinoma, usually GI
malar rash seen in lupus and
dermatomyositis. Will also have gottron lesions and heliotrope rash
antibodies in dermatomyositis
Positive ANA and anti-Jo-1. Make sure you don’t jump to Lupus! Get Anti-Jo-1 or Anti dsDNA
perimysial inflammation and perifascicular atrophy of muscle
dermatomyositis
endomysial inflammation with CD8+ cells
polymyositis
biopsy of skeletal muscle shows a lot of fat
Duchenne’s
inheritance of duchenne’s
X linked
dystrophin
allows cell to links muscle cytoskeleton to ECM
calf pseudohypertrophy with proximal muscle weakness
duchennes
lab in duchenne’s
creatinine kinase elevated
cause of death in duchenne’s
cardiac respiratory failure
Becker
mutation (not deletion) of dystrophin
lipoblast
liposarcoma
most common malignant soft tissue tumor in children
rhabdomyosarcoma
desmin positive tumor
rhabdomyosarcoma
site of rhabdomyosarcoma
head and neck.
Vag in young girls
apocrine gland
milky fluid, axilla, genitalia and areolae
sebaceous glands found in
hari follicle. holocrine secretion.
tight junction made up of
claudins and occludins
adherens junction made of
cadherins.
loss of which cadherin causes metastasis?
E cadherin
desmosomes made up of
keratin and desmoplakin
gap jnction protein
connexons
antibodies to desmosomes
pemphigus vulgaris
antibodies to hemidesmosomes
bullous pemphigoid
integrins
strengthens BM, binds laminin
hemidesmosome binds
keratin in basal cell to BM.
autoantibodies to hemidesmosome
bullous pemphigoid
rotator cuff innervated by
C5/6
most common rotator cuff injury
supraspinatus
action infraspinatus
laterally rotates arm
action teres minor
adducts arm and laterally rotates
action subscap
medially rotates and adducts
dislocation of lunate
carpal tunnel
common wrist fracture
avascular necrosis
intramuscular injection
damage to axillary nerve
supracondylar fracture of humerus
median nerve damage. Pain with pronation
falling and hitting heel of the hand
ulnar nerve damage.
medial forearm skin supplied by
T1
lateral forearm skin supplied by
C6
which nerves travel above flexor retinaculum?
palmar cutaneous branch of median nerve
ulnar nerve
innervates thenar muscles
abductor pollicis brevis
axillary nerve roots
C5,6
Radial nerve roots
C5-T1
Muscles radial nerve
BEST extensors Brachioradialis Extensors of wrist and fingers Supraspinator Triceps
wrist drop
radial nerve
“ape hand” or pope blessing when asked to make a fist
median nerve damage
loss of opposition of thumb, lateral finger flexion and wrist flexion
median nerve
medial finger and wrist flexion deficit
ulnar
radial deviation of wrist with flexion
ulnar nerve damage
median nerve roots
C5-8, T1
ulnar nerve roots
C8, T1
MC nerve roots
C5-7
Upper trunk compression
MC damage
cannot flex arm at elbow
MC nerve
sensory deficit over lateral forearm
MC damage
muscles supplied by MC nerve
biceps, brachialis, coracobrachialis
presentation: erb-duchenne
infant with trauma during delivery
Erb duchenne damages
C5-C6, axillary and musculocutaneous affected
Klumpke’s palsy
embryologic defect in C8, T1
atrophy of thenar/hypothenar, interosseous, with sensory deficit on medial forearm/hand
klumpke’s palsy
disappearance of radial pulse when moving head to ipsilateral side
klumpke
long thoracic nerve roots
C5-C7
ulnar claw=damage to which muscles
medial lumbrical function. Cannot extend digits 4 and 5
Median claw
caused by carpal tunnel
- loss of lateral lumbricals. 2/3 digit claw when extension
- distal median nerve damage
pope’s blessing
proximal median nerve lesion
-loss of opponens pollicis
situation causing long thoracic nerve damage
mastectomy
Thenar muscles
opponens pollicis
abductor pollicis brevis
flexor pollicis brevis
Hypothenar muscles
opponens digiti minimi
abductor digiti minimi
flexor digiti minimi
Dorsal interosseous muscles
abduct fingers (DAB)
palmar interosseous muscles
adduct fingers (PAD)
Peroneal nerve
everts and dorsiflexes
tibial nerve
inverts and plantarflexes
oBTURATOR INJURY
ANTERIOR HIP DISLOCATION
obturator motor deficit
thigh adduction
obturator sensory
medial thigh
femoral injury
pelvic fracture
femoral motor
thigh flexion and leg extension
femoral sensory
anterior thigh and medial leg
common peroneal injury
fibula neck fracture
common peroneal motor
foot eversion and dorsiflexion with foot drop/slap
sensory loss in anterolateral leg and dorsal foot
peroneal
knee trauma
tibial nerve
loss of sense on sole of foot
tibial
posterior hip dislocation
superior gluteal nerve or inferior gluteal nerve
positive trendelenburg
superior gluteal
can’t climb stairs, jump, rise from seated position or push downward
inferior gluteal
L2-L4
femoral obturator
L4-S2
common peroneal
L4-S3
tibial
L4-S1
superior gluteal
L5-S2
Inferior gluteal
slow twitch muscle with red fibers
type 1
fast twitch muscles with white fibers
type 2 muscle
Parathyroid hormone effect low dose vs high dose
low dose: builds bone
high dose: breaks down bone –> osteitis fibrosa cystica
How does estrogen affect bone
inhibits apoptosis in blasts
increases apoptosis in clasts
Type I osteoperosis
postmenopausal.
Fractures in type I osteoporosis
femoral neck fracture distal radius (colles' fracture)
treatment for osteoperosis
pulsatile PTH
SERMS
calcitonin
bisphosphon
osteopetrosis labs
low calcium, high ALP
osteitis fibrosa cystica labs
high calcium low phosphate high ALP high PTH
Osteomalacia labs
low calcium, phosphate
high ALP, PTH
Bone replaced by fibroblasts, collagen, and irregular bony trabeculae
polyostotic fibrous dysplasia
McCune albright
cafe au lait
precocious puberty
polyostotic fibrous dysplasia
Histol: giant cell tumor
spindle shaped cells with multinucleated giant cells
benign tumors of the bone
giant cell tumor and osteochondroma
Expansile glistening mass within medullary cavity
chondrosarcoma
Codman’s triangle (periosteum elevation) and sunburst pattern on x-ray
osteosarcoma
Treatment osteosarcoma
surgical resection and chemo
disease modifying agents in RA
methotrexate, sulfasalazine, TNF-alpha inhibitors
biopsy of sjogren’s glands
lymphocytic infiltration
sjogren’s assoc’d with
RA
Sjogren’s at risk for
B cell lymphoma
Diseases causing gout
Lesch NyHan and von Gierke’s disease
Why do you get gout after alcohol?
metabolites compete for same excretion sites as kidney
pseudogout–men or women?
same. gout affects more men
Tx for pseudogout
steroids, NSAIDs, colchicine
Causes of avascular necrosis
High dose steroids, alcoholism, sickle cell
pencil in cup deformity
psoriatic arthritis
Most common cause of death in SLE
nephritis
dsDNA
Lupus: specific, poor prognosis
anti-smith
Lupus: specific
false positive on syphilis tests
SLE–b/c of antiphospholipid antibodies
antihistone antibodies
SLE–drug induced
Lupus nephritis
diffuse proliferative
Lupus nephrotic syndrome
membranous glomerulonephritis
levels of what enzyme is high in sarcoidosis
ACE
Findings in sarcoidosis
- bilateral hilar adenopathy
- restrictive lung disease
- erythema nodosum
- bell’s palsy
- granulomas with schaumann and asteroid bodies
- hypercalcemia
Polymyalgia rheumatica associated with
temporal cell arteritis
lab findings in PMR
high ESR, normal CK
myositis ossificans
metaplasia of muscle to bone after trauma
Most likely cause of death in scleroderma
pulmonary fibrosis
Scl-70
scleroderma (anti-DNA topoisomerase)
anti-centromere antibody
CREST
Parakeratosis
hyperkeratosis with retained nuclei in stratum corneum
Acanthosis
epidermal hyperplasia
acantholysis
separation of epidermal cells (tombstoning in pemphigus vulgaris)
Causes of albinism
decreased melanin production from reduced tyrosinase activity
OR
neural crest cell migration problem
melasma
hyperpigmentation with pregnancy
melanocyte # in albinism vs vitiligo
albinism: normal melanocyte count
vitiligo: decrease in melanocytes
papular nevi
intradermal
flat nevi
junctional–btw dermis and epidermis
Ephelis
freckle. Has normal # melanocytes, more pigment
Which layers of skin are abnormal in psoriasis?
Increased stratum spinosum
Decreased stratum granulosum
auspitz sign
pinpoint bleeding spots from exposure of dermal papillae when scales are pulled
Leser-trelat sign
sudden appearance of multiple seborrheic keratoses which indicate an underlying malignancy
positive nikolsky sign
pemphigus vulgaris
reticular immunofluorescence
pemphigus vulg
IgG to desmoglein 1/3
pemphigus vulg
IgG against hemidesmosomes
bullous pemphigoid
linear immunofluorescence
bullous pemphigoid
eosinophils with tense blisters
bullous pemphigoid
pruritic papules, vesicles, and bullae with deposits of IgA at the tips of dermal papillae
dermatitis herpetiformis
Dermatitis herpetiformis is associated with
celiac disease
fever, bullae, necrosis, sloughing of skin and high mortality rate after giving a drug
Stevens Johnson
What causes erythema multiforme?
Infections
Drugs
Cancers
Autoimmune
Cause of acanthosis nigracans
visceral malignancy (and hyperinsulinemia)
erythema nodosum is caused by
TB
Leprosy
Crohn’s
Histoplasmosis
Coccidioides
Strep
Sarcoid
collarette scale
pityriasis rosea
sawtooth infiltrate of lymphocytes at dermal/epidermal junction
Lichen planus
Lichen planus associated with:
hepatitis C
UVA vs UVB
UVB=sunburn
UVA=tanning/photoaging
Staph scalded skin histology:
Exotoxin destroys kertinocyte attachment in the stratum granulosum
Toxic epidermal necrolysis histology
Destroys epidermal-dermal junction cells
Gas produced in necrotizing fasciitis
CO2 and methane
pink, pearly tumor with telangiectasias and rolled borders
BCC
palisading nuclei histology
BCC
SCC associated with
arsenic exposure
chronic draining sinuses
These cancers rarely metastasize
keratin pearls
SCC
keratoacanthoma
SCC variant that grows rapidly then spontaneously regress
Melanoma tumor marker
S-100
Treatment for melanoma
excision with appropriately wide margins
Risk of metastasis with melanoma
Breslow Depth!
Which factors tell you if a nevus could be melanoma?
asymmetry border color diameter > 6 Evolution
how to tx melanoma metastatic in pts with BRAF V600E mutation?
Vemurafenib, a BRAF kinase inhibitor
LTC/D/E4
bronchoconstriction
vasoconstriction
contraction of smooth muscle
increased vascular permeability
PGI2
inhibits platelet aggregation and promotes vasodilation
Prostacyclin effect
decreased: platelet aggregation vascular tone bronchial tone uterine tone
Prostaglandin effects
Increased uterine tone
decreased vascular tone
Decreased bonchial tone
aspirin mechanism
Irreversibly inhibits COX through acetylation, decreasing thromboxane A2 and prostaglandins
aspirin overdose
respiratory alkalosis with metabolic acidosis
aspirin tox
tinnitus, acute renal failure
NSAID tox
interstitial nephritis and renal ischemia (PGs dilate afferent arteriole)
COX-1
maintains gastric mucosa
Produces TXA2
Indications for bisphosphonates
hypercalcemia
paget’s disease of bone
tox: bisphosphonates
corrosive esophagitis
osteonecrosis of the jaw
Contraindications in gout
salicylates (probenicid). These depress uric acid clearance.
other allopurinol uses
extends life of Azathioprine and 6-MP which are metabolized by xanthine oxidase
febuxostate
inhibits xanthine oxidase
probenicid
Inhibits reabsorption of uric acid in PCT
colchicine
binds and stabilizes tubulin to inhibit polymerization and inhibit leukocyte chemotaxis
colchicine tox
massive diarrhea
Drugs for acute gout
NSAIDs and glucocorticoids
Entanercept
Fusion of TNF-alpha receptor and IgG1Fc
–binds up TNA alpha which is then phagocytosed
Infliximab/adalimumab
anti-TNF alpha monoclonal antibody
TNF-a indications
Crohn’s, rheumatoid arthritis, ankylosing spondylitis, psoriasis
A young child has his arm pulled and injures:
C8-T1 roots of the brachial plexus
- -Damages median and ulnar nerves
- -Total hand weakness
Sciatic nerve branches
common fibular
tibial
superficial fibular nerve
innervates lateral leg, foot eversion
deep fibular nerve innervates
anterior compartment of leg: dorsiflexors
deep fibular provides sensory to
between first and second toes
presentation of damage to common peroneal
foot drop
tibial nerve actions
plantar flexion and inversion
anterior to medial malleolus
saphenous and great saphenous vein
posterior to the medial malleolus
posterior tibial artery
tibial nerve
tendons of the flexor digitorum longus, flexor hallucis longus, tibialis posterior
matrix metalloproteases role in healing
Scar contractures
Postitive trendelenberg sign indicates
Weakness of gluteus medius/minimus on the leg which they are standing on.
—these are innervated by superior gluteal nerve
Inferior gluteal muscle innervates the
gluteus maximus muscle. Difficulty climbing stairs and rising from seated position
inheritance of duchenne’s
X linked.
calf pseudohypertrophy, replaced by fat
DUCHENNE. Begins with muscle hypertrophy, then changes to fat later on.
Acanthosis
Thickening of the stratum spinosum. Think psoriasis
dyskeratosis
abnormal permature keratinization. Think squamous cell cancer.
hyperparakeratosis
Retention of nuclei in stratum corneum
- -actinic keratosis
- -normal on mucous membranes
Hypergranulosis
lichen planus
Synovial fluid of gout vs septic arthritis
WBC<20,000 in gout, over 100K in septic arthritis
What gives elastin is elasticity?
cross linking of desmosine.
–Elastin is not hydroxylated and does not form a triple helix like collagen
Osteoma arises on
surface of facial bone
Osteoma associated with
gardner syndrome
osteoid osteoma shows up in what part of the bone
arises in cortex of diaphysis