MSK/Skin Flashcards
What is the function of t-tubules?
To ensure coordinated contraction
What is the pathogenesis of Osteogenesis Imperfecta?
Can’t make proper triple helix
What is the presentation of osteogenesis imperfecta?
Blue sclera, bone fragility, dental imperfections, hearing loss
What is the progression of Paget’s Disease?
Lytic (osteoclastic) –> Mixed (both) –> sclerotic (osteoblastic)
Who gets prepatellar bursitis?
Carpentars, plumbers etc who kneel a lot get erythema and joint pain
What is the MCC of hair loss in men and women?
Androgentic alopecia aka male pattern baldness (polygenic inheritance pattern w/ variable penetrance)
What does a distal ulnar lesion present with?
Can’t undo the fist
What does a proximal ulnar lesion present with?
Can’t form a fist
Distal vs proximal nerve lesion?
Distal: you can’t undo the action of the nerve
Proximal: you can’t do the action of the nerve
What needs to be monitored in ankylosing spondylitis?
Chest wall expansion
What does seborrheic keratosis look like?
Round, greasy, brown lesion that looks like it can be peeled off
What is the major cause of radiation burns?
UVB
What protects against UV light?
PABA
What accumulates in gout?
Monosodium urate crystals
What is the darkest line in a picture of the sarcomere?
Z line
What are the major hip flexors?
Psoas and Iliacus (especially when you sit up)
What does acanthosis nigricans look like?
Velvety, hyperpigmented thicekning
What causes a vertebral crush fracture?
Osteoporosis
What are your serum Ca and PO4 levels in osteoporosis?
Both are normal
What are the key traits of mitochondrial myopathy?
MERRF: ragged red fibers + myoclonic epilepsy
Leber optic neuropathy
MELAS: encephalopathy with stroke like episodes and lactic acidosis
What would be damaged in a anterior dislocation of the humerus?
Axillary nerve
What would be damaged in a humeral neck fracture?
Axillary nerve
What would be damaged in a mid-shaft fracture
Radial Nerve
What are the characteristics of a psoriasis lesion?
High mitotic activity above basale layer, reduced/absent granulosum, neutrophils may form spongiotic clusters in supericial dermis and parakeratotic stratum corneum
What is the action of Colchicine?
Inhibits LTB4 and microtubule polymerization?
What is the histology of Paget’s?
Multinucleate cells w/ 100s of nuclei TRAP + (these are osteocytes)
What does the sensory innervation of the lateral forearm?
Musculocutaneous (becomes lateral cutaneous after innervating the muscles)
What is the inheritance of achondroplasia?
Autosomal dominant
What do heterozygotes with achondroplasia look like?
They are short, large relative to head (membranous ossification unaffected)
What do homozygotes with achondroplasia look like?
They die at birth
Pathogenesis of achondroplasia?
FGFR3 constitutive expression inhibits chondrocyte proliferation
What do Gottron’s papules look like?
Red papules w/ scales over bony prominence (on knuckles of hands)
Where is hematogenous osteomyelitis located?
In the metaphysis
Where else do you get sclerosis from fibrin/collagen besides in skin in Scleroderma/CREST
Renal, GI, CV, pulmonary (get pulmonary HTN)
In what settings would you see Carpal Tunnel Syndrome?
Hemodialysis related amyloidosis (beta 2 microglobulin deposition); also in pregnancy, hypothyroidism, RA, DM
Which gland causes sweat malodor?
Apocrine gland (secrete sweat then smell because of bacteria)
What drugs cause drug-induced lupus?
Isoniazid, Procainamide, Hydralazine
What would skin where glucocorticoid has been applied look like?
Derma atrophy, drying, cracking, tightening (GC reduce collagen and glycosaminoglycan production)
What is the psoas sign?
Pain with extension of the hip?
If something on the skin looks comedomal and nodular, what is it?
Acne
What is the histological finding of eczematous dermatitis?
Spongiosis
What is the diagnosis? Loss of anocutaneous reflex + saddle anesthesia.
Cauda equina syndrome
What is made of claudins and occludens?
Tight junctions
What is the unhappy triad?
MCL, medial lemniscus, ACL tear due to contact on a planted foot
What adducts the arm?
Subscapularis and teres minor
What laterally rotates the arm?
Infraspinatus and teres minor
What is it if you have child with extended elbow and pronated forearm?
Nursemaid’s
What do you see if baby has upward force on arm during delivery?
Horner and klumpke
What does proximal lesion look like?
Can’t do the action of the nerve
What does distal lesion look like?
Can’t undo the action of the nerve
What is the diagnosis? Saddle anesthesia, bladder and rectum flaccid paralysis, impotence
Conus Medularis Syndrome
Which muscle fiber type has more mitochondria and myoglobin?
Type 1
Which muscle fiber does sustained contraction
Type 1
Which muscle fibers do fast twitch and have white fibers?
Type 2
What happens to muscle fibers with weight training?
Type 2 hypertrophies
What do osteoblasts orginate from?
Mesenchymal stem cells
What is the inheritance pattern of achondroplasia?
AD