MS UWorld 2 Flashcards
young man with low back pain and morning stiffness with inflammation and early fusion of sacroiliac joint. Dx, associated with
Ankylosing spolndylitis - associated with HLA B27, which is a specific HLA class I serotype
Anterior mediastinal mass in myasthenia gravis
Majority of MG patients have thymoma or thymic hyperplasia.
Both the thymus and the inferior parathyroids are from the 3rd pharyngeal pouch
Ecthyma gangrenosum
Cutaneous necrotic disease with strong association with pseudomonas bacteremia and septicemia. Bacteria invades perivascularly and release exotoxins that cause vascular destruction and insufficiency to patches of skin.
Function of PCL
Prevents anterior motion of femur relative to tibia (or posterior motion of tibia relative to femur) when the knee is flexed.
Insect (bee) sting hypersensitivity
Type I
Black color of urine upon standing for a while, no other symptoms noted
Alkaptonuria - benign disorder of tyrosine metabolism. Autosomal recessive deficiency of homogentisate oxidase blocks phenylalanine and tyrosine conversion to fumarate. Homogentisic acid accumulates in urine and can oxidize to black color. (it can also cause blue/black pigmentation and arthralgias)
14 y/o boy with conductive hearing loss, multiple fractures after minor trauma. Mutation in type I collagen.
Osteogenesis imperfecta
Thiazide diuretic side effects
Hypokalemic metabolic acidosis, hyperGLUC: glucose, lipid, uric acid, calcium
Antibodies in rheumatoid arthritis
Rheumatoid factor: IgM against Fc portion of self IgG
Cystathionine beta synthase deficiency is enzyme defect present in:
classic homocystinuria
Pleiotropy
occurrence of multiple phenotypic manifestations often in different organ systems as a result of a single genetic defect
Baby with recurrent skin infections without pus formation, delayed separation of umbilical cord
Leukocyte adhesion deficiency, deficiency in CD18 integrin.
____ are multinucleate cells responsible for bone resorption
Osteoclasts
What are the 2 most important factors for osteoclast differentiation, and where do they come from?
RANK-L and M-CSF both come from osteoblasts
Type I (slow twitch) and Type II (fast twitch) fibers - which ones have lots of myoglobin and glycogen?
Type I are aerobic: lots of myoglobin. Postural muslces
Type II are anaerobic, lots of glycogenolysis
Long term serum uric acid lowering therapy
Note: really only used for chronic recurrent cases.
Prebenecid/sulfinpyrazone inhibit resorption of uric acid in PCT
Allopurinol and febuxostat are xanthine oxidase inhibitors. Decreases uric acid production in purine metabolism.
Allopurinol is the best choice for tophaceous gout
Sensory receptors that inhibit contraction when a muscle exhibits too much force
Golgi tendon organ. Negative feedback system that regulates and maintains muscle tension. Sensitive to increases in muscle tension but insensitive to passive stretch.
Muscle spindles
Arranged in parallel with fibers, sensitive to changes in muscle length. Mediate stretch (DTR) reflexes
Upregulation in RANK receptor leads to
increased osteoclast bone resorption
Major toxin of C. perfringes
Lecithinase, aka phospholipase C or alpha toxin: catalyzes splitting of phospholipid molecules, leading to membrane destruction, cell death, necrosis, hemolysis
Damage to radial nerve
Wrist drop, decreased grip strength, loss of sensation over posterior arm/dorsal hand
Comes from midshaft fracture of humerus or compression of axilla (Saturday night palsy)
3 major organisms for necrotizing fasciitis
Strep pyogenes, Staph aureus, Clostridium perfringes
Resting potential of cell depends on conductance of:
high potassium and some sodium conductance
Where does the majority of collagen synthesis take place?
RER
Elderly woman, tea and toast diet, bleeding gums
Scurvy, vitamin C deficiency impairs collagen hydroxylation
TNF-alpha inhibitors - side effects
Etanercept, infliximab, adalimumab - predispose to infection, including reactivation of latent TB
Presentation of Lambert-Eaton syndrome
Proximal muscle weakness, autonomic symptoms like dry mouth, eye stuff, impotence. Often as a paraneoplastic syndrome from small cell lung cancer
Most commonly injured nerve in the leg, effects
Common peroneal nerve. Very superficial when it goes around the neck of the fibula. Injury causes loss of sensation over dorsum of foot, and weakness of dorsiflexion and eversion
Succinylcholine
depolarizing NMJ blocker administered for rapid sequence induction and intubation. Rapid onset. Paralytic action can be reversed by anticholinesterases (stigmines).
What is most responsible for peak bone mass?
Genetic factors
What test should you do before starting etanecept therapy?
PPD - TNF-alpha inhibitors might cause TB reactivation
Sustained involuntary muscle contractions which force certain parts of the body into abnormal, painful movements
Dystonia
Sudden, brief, sometimes shock-like muscle contraction
Myoclonus
Treatment for a pt with hypertension, CHF, and osteoporosis
hctz
Fibromyalgia
Chronic disorder, widespread musculoskeletal pain associated with stiffness, paresthesias, poor sleep, fatigue. Often worse with exercise. Multiple symmetrically distributed tender spots over muscles, joints, tendons (spine of scapula, lateral epicondyle, medial fat pad of knee). Women more than men.
Tx: exercise, antidepressants, anticonvulsants
Child with moderate growth retardation and prominent brown stains on teeth - what did his mom use in pregnancy?
Tetracycline
Musculocutaneous nerve, injury
C5-7. Innervates major upper arm flexors, and sensory innervation to skin of lateral forearm.
Injury causes loss of forearm flexion, loss of sensation over lateral forearm
Gluteus medius gate:
hips dip downwards when ipsilateral foot is lifted off ground.
Safe place for intramuscular injections in gluteal region
Superiolateral region. Superiomedial risk hitting sciatic nerve and gluteal nerves
How are osteocytes connected?
Via gap junctions
Contracture
Deformity in wound and surrounding tissue. Comes from excessive matrix metalloproteinase activity and myofibroblast accumulation in wound margins during wound healing
Erythema infectiosum
Aka fifth disease, caused by parvovirus B19. Bright red rash on cheeks, lacelike rash on trunk and extremities
Subdural hematoma and bilateral retinal hemorrhages in infant is suggestive of
Shaken baby syndrome, child abuse
