uWorld 54 Flashcards
symmetrical proximal muscle weakness
increasing difficulty climbing stairs, getting up from chain, carrying heavy objects, combing hair
INCREASED MHC CLASS I expression on the sarcolemma and CD8+ cells
POLYMYOSITIS
EVELVATED MSUCLE ENZYMES (CK, aldolase)
anti- ANA, Jo-1(aka anti-histidyl-tRNA)
ENDOMYSIAL mononucelar infiltrate, patchy necrosis, and regeneration and fibrosis of the muscle fibers
associated with: INTERSTITIAL LUNG DISEASE, MYOCARDITIS
in multiple myeloma what causes the BONE RESORPTION
section of IL-1 (osteoclast activating factor) and IL-6 by neoplastic cells- activates osteoclasts
bone pain, pathologic fractures, “punched out” lytic lesions on X-ray
HYPERCALCEIMIA from bone destruction- CONSTIPATION, CONFUSION, FATIGUE
what is higher in pulmonary vein than artery from the RAAS
ANGIOTENSIN II- potent vasoconstrictor of the systemic circulation and causes a rise in blood pressure (increased after load) that worsens cardiac output
difference in minute vent and alveolar vent is what
dead space (tidal volume times Paco, Peco, Paco)
what causes hereditary pulmonary HTN
INACTIVATION mutation in BMPR2, which is transmitted AD
predisposition for dysfunctional endothelial and SMOOTH MUSCLE CELL PROLIFERATION
second insult (infection, drugs, ion channel defects) is then thought to activate the disease process, which involves increased ENDOTHELIN (vasoconstrictor) and decreased NO (vasodilator) and prostacyclin (vasodilator and platelet inhibitor)- TWO HIT HYPOTHESIS
vasoconstriction with vascular smooth muscle proliferation
increased pulmonary artery pressure can cause what
dyspnea, fatigue, and can be heard as an ACCENTUATION of the PULMONARY component of the SECOND HEART SOUND (P2)
can lead to cor pulmonale (angina, DJP, hepatic congestion, and peripheral edema)
how is relative risk calculated
(a/(a+b))/(c/(c+d))
used in cohort
how is odds ratio calculated
OR: ad/bc
used in case-control
perforating stab wound right above clavicle, what is pierced
LUNG APICES and CERVICAL PLEURA extend above CLAVICLE and FIRST RIB
stab wounds immediately above the clavicle and lateral to the manubrium can puncture the pleura and acute pneumothorax, tension pneumothorax, or hemothroax
how do beta blockers lower BP
reducing myocardial contractility and heart rate
decreasing renin release by the kidney
what are the areas in the colon most susceptible to non-occlusive ischemia (like due to diabetes or atherosclerotic arterial disease)
2 WATERSHED ZONES splenic flexture (SMA and IMA) RECTOSIGMOID JUNCTION (sigmoid and superior rectal arteries)
complications: acidosis, sepsis, gangrene, perforation
pale mucosa and petechial hemorrhages
myxomatous changes of large arteries are found in what
CYSTIC MEDIAL DEGENERATION
characterized by fragmentation of elastic tissue (“basket weave” pattern) and separation of the elastic and fibromusclar components of the tunica media by small, cleft-like spaces that become filled with amorphous extracellular matrix
MARFAN SYNDROME- AORTIC ANEURYSMS and DISSECTIONS
what is beta-aminopropionitrile (a chemical found in certain kinds of sweat peas)
causes inhibition of lysyl oxidase, an enzyme responsible for cross-linking elastin fibers and collagen fibers
ingestion can cause change in elasticity of the aorta that mimics myxomatous degeneration
a PALPABLE but NONTENDER GALLBLADDER (courvoisier sign), weight loss, and obstructive jaundice (pruritic, dark urine, dark stool) are indicative of what
ADENOCARCINOMA of the HEAD of the PANCREAS compressing the biel duct
associated with SMOKING, age, DM, chronic pancreatitis, genetic predisposition (hereditary pancreatitis, MEN 1, HNPCC, FAP)
a low-fiber diet is associated with what kind of cancer
colon adenocarcinoma
what is released from HEMOGLOBIN in the lungs
HYDROGEN ION (the BOHR-HALDANE effect)
in the peripheral tissues relate of O2 from hemoglobin is enhanced by increased pCO2 and the resultant decrease in pH (BOHR effect)- bicarb is sent out of RBC for Cl- and H+ ions remain in the erythrocytes (buffered by HISTIDINE RESIDUES in hemoglobin)
when deoxygenated blood enters the alveolar capillaries of the lung- the rise in pO2 increased the binding of oxygen to hemoglobin and causes release of HYDROGEN IONS and CO2 from hemoglobin (HALDANE EFFECT)
HYDROGEN ions are ON HEMOGLOBIN
CHLORIDE is IN RBC
levels of what decrease in lactase deficiency
pH- the bacterial fermentation of lactose produces short-chain fatty acids (acetate, butyrate, and propionate) which LOWER STOOL pH (less than 6) and HYDROGEN GAS, which cases flatulence
also get INCREASED HYDROGEN in the breath (hydrogen breath test)
elevated stool osmotic gat (over 125mOsm) causing OSMOTIC DAIRRHEA
a non bicuspid aorta may present how (seen in turner syndrome)
early SYSTOLIC, high-frequency CLICK over the right second interspace
these valves at risk for stenosis, insufficiency, and infection
is HPV enveloped
NO
the conversion of alpha-helices to beta sheets requires what
breaking and reforming HYDROGEN BONDS
these are SECONDARY STRUCTURES- hydrogen bonds are primary stabilizing force
what forces stabilize tertiary protein structure
ionic bonds
hydrophobic interaction
hydrogen bonds
DISULFIDE BONDS (strong covalent bonds b/w 2 cysteine residues within the same polypeptide chain that enhance a proteins ability to WITHSTAND DENATURATION)
how do triptans work
5-HTB/D agonists
inhibit release of vasoactive peptides, promote vascoconstricon, blocking pain pathways in brainstem
post-synaptic norepi blockade is used for what in migranes
beta-blockers for prophylaxis
how does bupropion work
dopamine and norepi reuptake inhibitor used for depression and smoking cession
