MSK - OMG - SCURRED - DIES. Flashcards
(111 cards)
1
Q
what are tight junctions composed of?
A
- occludins / claudins
- prevent paracellular solute movement
2
Q
what are cadherins?
A
Ca2+ dependent adhesion proteins –> found in adherins junction & connects actin cytoskeletons of adjacent cells
3
Q
what is the significance of cadherins?
A
loss of E-cadherin –> metastasis
4
Q
what is the disease associated w/ autoantibodies against desmosomes?
A
pemphigus vulgaris
5
Q
what are desmosomes?
A
structural support via keratin interactions
6
Q
what are integrins?
A
membrane proteins binding to collagen / laminin in BM –> maintain “BM integrity)
7
Q
what is the significance of an abnormal passive abduction test (Valgus)
A
MCL injury
8
Q
significance of an abnormal passive adduction? (varus)
A
LCL injury
9
Q
mcmurray test
A
pain on external rotation –> medial meniscus
pain on internal rotation –> lateral meniscus
10
Q
unhappy triad
A
-ACl
MCL
medial meniscus injury
11
Q
where do you inject to relieve delivery pain?
A
pudendal nerve –> ischial spine
12
Q
rotator cuff muscles (4)
A
1) supraspinatus
2) infraspintaus
3) teres minor (axillary nerve)
4) subscapularis
13
Q
supraspinatus function
A
abducts arm
14
Q
infraspintaus function
A
laterally rotates arm
15
Q
teres minor function
A
adducts / laterally rotates arm
16
Q
subscapularis function
A
medially rotates / adducts arm
17
Q
where is scaphoid found and why is ti prone to avascular necrosis?
A
- anatomical snuff box
- most commoonly fractured carpal bone
- avascular necrosis b/c: retrograde blood supply
18
Q
what are the wrist bones / describe what is seen on xray?
A
So Long To Pinky, Here Comes The Thumb Scaphoid Lunate Triquetrum Pisiform Hamate Capitate Trapezoid Trapezium
Trapezium / trapezoid overlap on the base of the thumb. Capitate is the largest, well differentiated bone on the 1st row.
Scaphoid is the biggest bone on the bottom row (right next to distal radius)
Triquetrum/pisiform overlap
19
Q
what nerve runs adjacent to the hook of the hamate?
A
ulnar nerve
20
Q
guyon canal syndrome?
A
compression of the ulnar nerve
21
Q
erbs palsy injury
A
tear of upper trunks C5-C6 roots
22
Q
examples of erb palsy injuries:
A
infants: lateral traction on neck during delivery
adults: trauma
23
Q
functional deficits from erb’s palsy
A
1) deltoid/supraspinatus = no abduction (arm hangs loose)
2) infraspinatus = no lateral rotation (arm rotated medially)
3) biceps = no flexion / supination (arm pronated + extended
24
Q
klumpke palsy injury + causes
A
tear of lower trunk: C8-T1
1) infants: upward force during delivery
2) adults: trauma: grabbing tree to break a fall
25
klumpke deficits
intrinsic hand muscles: lumbricals, interossei, thenar, hypothenar -->
1) total CLAW hand: unable to flex MCP, unable to extend DIP / PIP
26
thoracic outlet syndrome
compression of lower trunk / subclavian vessels
27
typical injury causing thoracic outlet syndrome
cervical rib injury / pancoast tumor
28
deficits in thoracic outlet syndrome
intrinsic hand muscles:
1) lumbricals
2) interossei
3) thenar
4) hypothenar
29
thoracic outlet syndrome presentation
atrophy of intrinsic hand muscles: ischemia, pain, edema due to vascular compression
30
winged scapula injury / causes
axillary node dissection / stab wounds --> long thoracic nerve
31
deficit on winged scapula
serratus anterior: inability to anchor scapula --> cannot abduct arm above horizontal
32
axillary (C5-C6) cause of injury
cause: fractured surgical neck of humerus (or anterior humerus dislocation)
33
axillary presentation
1) flattened deltoid
2) loss of arm abduction at shoulder (>15 degrees)
3) loss of sensation over deltoid muscle / lateral arm
34
musculocutaneous (C5-C7) causes of injury
upper trunk compression
35
musculocutaneous presentation
1) loss of forearm flexion / supination
| 2) loss of snsation over the lateral forearm
36
radial nerve (C5-T1) causes of injury (2)
1) midshaft fracture of humerus
| 2) compression of axilla
37
radial nerve presentation
1) wrist drop (loss of extension along elbow, wrist, fingers)
2) dec. grip strength (limited action of flexors)
3) loss of sensation over posterior arm / forearm + dorsal hand
38
median (C5-T1) causes of injury (2)
1) supracondylar fracture of humerus (Proximal)
| 2) carpal tunnel syndrome via wrist laceration (distal)
39
median nerve presentation
"ape hand" / "pope's blessing
1) loss of wrist / lateral finger flexion, thumb opposition, 2/3 lumbricals
2) loss of sensation over thenar eminence
40
ulnar nerve (C8-T1) causes of injury (2)
1) fracture of medial epicondyle of humerus --> HAHA FUNNY BONE (proximal)
2) hook of hamage (distal)
41
ulnar deficit presentation
Ulnar claw on digit extension
1) if proximal: radial deviation
2) loss of wrist / medial finger flexion, abduction/adduction
3) loss of sensation over medial 1.5 fingers, including hypothenar eminence
42
what nerve deficit best defines clawing?
distal median / ulnar nerves
43
when do proximal ulnar / median lesions present?
voluntary flexion of the digits
44
thenar muscles are controlled by?
median OAF:
Opponens pollicis
Abductor pollicis brevis
Flexor pollicis brevis
45
hypothenar muscles are controlled by?
ulnar nerve
Opponens digit minimi
Abductor digit minimi
Flexor digit minim
46
what are the functions of the thenar / hypothenar muscles?
Oppose
Abduct
Flex
(OAF)
47
DAB
dorsals ABduct
48
PAD
Palmars ADduct
49
causes of obturator nerve injury
pelvic surgery
50
obturator nerve presentation (L2-L4)
dec. thigh sensation (medially) + dec. adduction
51
femoral nerve injury (L2-L4)
pelvic fracture
52
presentation of femoral nerve injury
dec. thigh flexion / leg extension
53
common peroneal nerve (L4-S2) cause of injury
1) trauma / compression of the Lateral Leg
| 2) fibular neck fracture
54
common peroneal nerve presentation
foot drop: inverted / plantarflexed at rest, loss of eversion + dorsiflexion
sensation loss: dorsum of foot
55
tibial (L4-S2) cause of injury:
knee trauma
1) proximal lesion = baker cyst
2) distal lesion = tarsal tunnel syndrome
56
superior gluteal (L4-S1) cause of injury
1) posterior hip dislocation
| 2) polio
57
presentation of superior gluteal injury
1) trendelenburg sign/gait: weight-bearing leg cannot abduct and maintain pelvic alignment
* lesion is contralateral to the side of the hip that drops
58
inferior gluteal injury (L5-S2)
posterior hip dislocation
59
inferior gluteal injury presentation
1) difficulty climbing stairs / rising from seated position
| 2) loss of hip extension (due to deficit in the maximus
60
mnemonic for peroneal nerve
PED: peroneal EVERTS and DORSIFLEXES.
injury = foot dropPED
61
mnemonic for tibial nerve
TIP: Tibial Inverts & Plantarflexes;
injury = no TIP toes
62
where does the sciatic nerve run and how does it split?
posterior thigh --> common peroneal + tibial
63
long thoracic nerve is paired with what artery?
lateral thoracic
64
surgical neck of the humerus has what nerve / artery?
-axillary nerve
| posterior circumflex artery
65
midshaft of the humerus has what nerve / artery?
radial nerve
| deep brachial artery
66
distal humerus = what nerve/artery?
median nerve
| brachial artery
67
popliteal fossa has what nerve/artery?
tibial nerve
| popliteal artery
68
posterior to medial malleolus is what nerve / artery
tibial nerve
| posterior tibial artery
69
muscle contraction steps (6)
1) AP depolarization --> voltage-gated Ca2+ channels open --> NT release
2) post-snayptic binding --> depolarization at motor end plate
3) depolarization down T-tubule
4) depolarization of voltage-sensitive dihydropyridine receptor, mechanically coupled to the ryanodine receptor of the sarcoplasmic reticulum triggers Ca2+ release from SR
5) Ca2+ released binds to troponin C --> conformational change moving tropomyosin out of the myosin-binding groove on actin filaments
6) myosin releases bound ADP + Po4 displacement
70
what bands are shortened during muscle contraction?
H& I bands b/w Z lines
71
what bands remain the same length during muscle contraction?
A band
72
what are the regulators of smooth muscle contraction?
Ca2+ --> MLCK --> contraction
| nitric oxide --> MLCP --> relaxation
73
where does endochondral ossification occur?
axial / appendicular skeleton, base of skull
74
what is mechanism of endochondral ossification?
cartilaginous bone made first by chondrocytes.
osteoclasts / osteoblasts replace w/ woven bone --> remodelled to lamellar bone
75
what is the mechanism of membranous ossification:
woven bone formed directly w/o cartilage --> remodelled to lamellar bone
76
what is the different in origin of osteoblasts and osteoclasts?
1) osteoblasts originate from mesenchymal cells in the periosteum
2) osteoclasts are derived from macrophages / monocytes
77
what is the genetic inheritance of achondroplasia?
constitutively activated FGFR3 --> inhibition of chondrocyte proliferation
autosomal dominant inheritance
78
histology of osteoporosis
trabecular spongy bone loses masses / interconnections
79
what are the lab values for calcium / phos in osteoporosis?
normal Ca / PO4 values
80
what is denosumab?
monoclonal antibody against RANKL
| used for osteoporosis
81
pathogenesis of osteopetrosis
mutations in carbonic anhydrase II impair osteoclast ability to create acidic environment necessary for bone resorption
82
lab findings of osteomalacia
hyperactive osteoclasts --> incr. ALP (osteoblasts require alkaline environment)
83
paget disease of bone histology findings
mosaic pattern of woven / lamellar bone
84
associated risks of paget's disease?
1) incr. blood flow from arteriovenous shunts --> high-output heart failure
2) incr. risk of osteogenic sarcoma
85
what is artery involved in AVN of femoral head?
medial circumflex femoral artery
86
what is osteitis fibrosa cystica?
brown tumors due to fibrous replacement of bone, subperiosteal thinning
87
causes of 1* hyper PTH
1) idiopathic parthyroid hyperplasia
2) adenoma
3) carcinoma
88
2* hyper PTH causes
1) ESRD (dec. Po4 excretion + production of activated vit D)
89
giant cell tumor
1) locally aggressive benign tumor aroud knee.
2) soap bubble appearance on X-ray w/ multinucleated cells
3) 20-40 yo at epiphyseal end of long bones
90
osteochondroma
1) most common benign tumor, affecting males < 25 yo
| 2) mature bone w/ cartilaginous cap, rarely transforms to chondrosarcoma
91
osteosarcoma risks
1) paget disease of bone
2) bone infarcts
3) radiation
4) familial retinoblastoma
5) Li-Fraumeni syndrome (germline P53 mutation)
92
x-ray findings of osteosarcoma
1) codman triangle (due to elevation of periosteum
| 2) sunburst pattern on x-ray
93
ewing sarcoma genetic mutation
11,22
onion skin appearance on bone
anaplastic small blue cell malignant tumor
-extremely aggressive w/ early metastases, but responsive to chemo
94
chondrosarcoma
rare, malignant, cartilaginous tumor --> seen as expansile glistening mass w/in medullary cavity
95
pathophysiology of RA:
cytokines + type III/IV hypersensitivity
96
what is composition of rheumatoid nodules?
fibrinoid necrosis
97
pseudogout findings
basophilic, rhomboid crystals weakly positively birefringent
98
presentation of pseudogout
pain / effusion in a joint, due to deposition of calcium pyrophosphate w/in the joint space (chondrocalcinosis seen on x-ray)
99
what are libman-sacks endocarditis?
wart-like vegetations on both sides of the valve, often seen in SLE
100
what type of hypersensitivity is lupus nephritis?
type III
101
findings for sarcoidosis
- immune mediated, widespread noncaseating granulomas
- elevated ACE
- CXR Bilateral hilar adenopathy / reticular opacities
102
polymyalgia rheumatica symptoms
pain / stiffness in shoulders, hips, associated w/ fever malaise, weight loss
103
what is PMR associated w?
temporal arteritis
104
fibromyalgia
chronic, widespread musculoskeletal pain, associated w/ stiffness, paresthesia, poor sleep, fatigue
105
treatment for fibromyalgia
- exercise
- antidepressants (TCAs, SNRIs)
- anticonvulsant
106
polymyositis
progressive, symmetric proximal muscle weakness, with endomysial inflammation w/ CD8_ T cells
107
dermatomyositis:
polymyositis + malar rash, Gottron papules, heliotrope rash, with increased risk of occult malignancy
108
what's the difference, mechanistically, b/w polymyositis vs. dermatomyositis?
1) polymyositis = endomysial inflammation, CD8+ associated
| 2) dermatomyositis = perimysial inflammation, CD4+ associations
109
comparison of pathophys of myasthenia gravis vs. lambert-eaton?
1) myasthenia gravis = autoantibodies to postsynaptic Ach receptor
2) lambert-eaton = autoantibodies to pres-synaptic Ca2+ channel --> dec. ACh release
110
acantholysis vs. acanthosis?
1) acantholysis = separation of epidermal cells --> i.e.: pemphigus vulgaris
2) acanthosis = epidermal hyperplasia --> i.e.: acanthosis nigricans
111
characteristic of urticaria
superficial dermal edema + lymphatic channel dilation
