UWorld Pics Flashcards
Name the 4 muscles of the rotator cuff
SITS
- supraspinatus
- infraspinatus
- teres minor
- subscapularis
Activity of opoid analgesia
- inhibits intracellular Ca2+ influx at presynaptic neuron
- stimulates K+ efflux at postsynaptic neuron
Differentiate type of virally-acquired resistance:
reassortment vs. recombination
Recombination = crossing over and homologous recombination btwn genes on chromosomes
Reassortment = when segmented viral segments exchange entire segments
Name mechanism by which a drug can exert chronotropic w/o inotropic effects (target which ion transporter)
Drug that can change HR (chronotropy) w/o altering contractility (inotropy) works at the nodal pacemaker cells and not at the ventricular cells
- so need to work on the If (funny current) of phase IV (present in nodal action potential and not ventricular action potential)
- b/c both use L-type Ca2+ channels during phase 2 and K+ rectifier in stage 3
- ventricular cells use rapid Na channels in phase 0
Differentiate structure injured in anterolateral vs. anteromedial humeral fracture
Anterolateral humeral fracture causes injury to the radial nerve
Anteriomedial humeral fracture causes injury to either (or both) brachial artery and median nerve
What structures do you cut thru for a surgical airway?
Cut thru the superficial cervical fascia and the cricothyroid membrane
-not any platysma or thyroid or cartilage (kinda the hole point is to find the place btwn the thyroid cartilage and cricoid cartilage to make the easiest incision)
Name the branches of the external carotid artery
From inferior to superior
Posteriorly: ascending pharyngeal, occipital, posterior auricular
Anteriorly: superior thyroid, lingual, facial, maxillary
Explain the role of fibronectin
(a) Role in malignancy
Fibronectin = part of the cellular adhesion complex
-integrin is a transmembrane protein that binds to intracellular matrix proteins (ex: actin) then connects outside cell to proteins such as fibronectin or laminin
Then fibronectin or laminin connect to ECM collagen
(a) Different integrins can lose ability to bind to fibronectin properly, giving cells malignant potential
What enzyme is responsible for
(a) Green discoloration of few day old bruises
(b) Conjugating bilirubin
(a) Heme –> (heme oxygenase) –> biliverdin
Biliverdin is green in color, so heme oxidase is responsible for greenish hue
Then biliverdin –> biliverdin reductase (in macrophages) –> unconjugated bilirubin
(b) UCB –> UGT (glucuronyl transferase) –> conjugated bilirubin
Then this conjugated bilirubin is excreted into intestinal lumen where bacteria act on it, creating urobilinogen which colors stool and urine
Name the structure that Meckel diverticulum arises from
Meckel diverticulum (true diverticulum containing all 3 layers of the abdominal wall) is 2/2 incomplete obliteration of the omphalomesenteric (also called vitelline) duct
-vitelline duct connects midgut lumen and yolk sac in early embryo
What enzyme catalyzes the first step of base excision repair?
(a) The third?
- Glycosylase cleaves altered base
- Endonuclease cleaves 5’ end
(a) 3. Lyase cleaves 3’ end - DNA polymerase fills single nucleotide gap
- Ligaseseals nick
BP, K+ status seen in
(a) 11-beta hydroxylase deficiency
(b) 21-hydroxylase deficiency
(c) 17-alpha hydroxylase deficiency
(a) 11-beta hydroxylase deficiency => deficient aldo and cortiso, but build up of deoxycorticosterone which is a weak mineralocorticoid => hypertension, hypokalemia, ambiguous genitalia
(b) 21-hydroxylase deficiency: no aldo or cortisol, no aldo deoxycorticosterone => hypotension, hyperkalemia, ambiguous genitalia
- mineralocorticoid deficiency predominates
(c) 17-alpha deficiency = aldo excess => hypertension, hypokalemia
Name key histologic feature of Graves disease
“Scalloping of colloid” materal: see pink material in the lumen not firmly up against follicular cells (see white btwn colloid and follicular cells)
-excess colloid in the lumen scallops up against follicular cells
Key urinalysis finding of primary hyperparathyroidism
Primary hyperparathyroidism: increased urinary cAMP
- PTH receptor medicated by Gs which activates adenylate cyclase (catalyzes ATP –> cAMP)
- so excess PTH effect on kidney = excess cAMP in renal tubules cells that gets excreted out in urine
3 layers of the adrenal cortex and what they produce
‘GFR’- “deeper you go the sweeter it gets”
Zona Glomerulosa- mineralocorticoid (aldo)
Zona Fasciculata- glucocorticoid (cortisol)
Zona reticulata- androgens
Distinguish which enzyme works on pyruvate when O2 is vs. is not present
O2 present: pyruvate makes the most ATP by conversion into acetyl coA by pyruvate dehydrogenase
O2 not present (ex: mesenteric ischemia): intracellular NADH accumulates and inhibits pyruvate dehydrogenase, pyruvate then shunted to make lactate by lactate dehydrogenase, regenerating more NADH
Distinguish microscopic appearance of the following types of kidney stones
(a) Calcium oxalate
(b) Triple phosphate
(c) Uric Acid
(d) Cystine
Microscopic apperance (in order of descending frequency of type of stone)
(a) Calcium oxalate: octahedron: diamoid w/ ‘X’ shape in middle
(b) Triple phosphate (Magnesium ammonia phosphate) stone: rectangular prism, “coffin lid” appearance
(c) Uric acid stones: yellow or red/brown, diamoid or rhomboid
(d) Cystine: flat, yellow hexagon
Actvity of glucokinase
Glucokinase phosphorylates Glucose –> G-6-P
- acts as glucose sensor, b/c has lower affinity for glucose than hexokinase so only takes glucose into pancreatic islet cell when serum glucose is high enough
- once serum insulin high enough, glucose taken into pancreatic islet by GLUT2 then converted into G6P by glucokinase so it stays inside the cell (G6P trapped inside cell while glucose is not)
Activity of pyruvate carboxylase
Pyruvate carboxylase catalyzes pyruvate –> oxaloacetate inside the mitochondria as a key step of gluconeogenesis
Differentiate the histologic features of inflammation seen in UC vs. Crohn Disease
UC: inflammation manifests as crypt abscesses = see neutrophils in the crypts of the SI (crypts are the downward protruding parts)
Crohn disease: lymphoid aggregates w/ non-caseating granuloma formation
Differentiate the gross pathologic features of UC vs. Crohn Disease
UC: ulcers are by definition mucosal and submucosal (not full thickness)- get pseudopolps (bumps from healing ulcers) and ‘lead pipe’ appearance on imaging 2/2 loss of haustra in the colon
Crohn: transmural, so then myofibroblasts come in to repair. Get cobblestoning (scars), creeping fat (myofibroblasts have contractile properties), and strictures (2/2 full wall thickness)
Spinal cord tract damaged in tabes dorsalis
Tabes dorsalis = manifestation of neurosyphilis
-get sharp shooting pains in extremities, loss of proprioception (positive Rombergs), parasthesias
Spirochetes damage the dorsal columns
What is the arcuate fasciculus?
Arcuate fasciculus attaches Broca’s and Wernicke’s area, so Wernicke’s area heps you understand the language, then you can respond w/ fluent language w/ help of Broca’s area
-injury to arcuate fasciculus =pt unable to repeat phrases, speech is fluent and comprehension is intact b/c Broca’s and Wernicke’s areas respectively are not impacted
Differentiate the two proteins used for retrograde vs. anterograde axonal transport
Dynein is used for retrograde transport- aka how HSV-1 gets from skin to the trigeminal sensory ganglia where it lays dormant
Then kinesin molecule transports the virus anterograde for reactivation
