Mixed review 0502Q Flashcards
anterior surface of heart is mostly which chamber?
RIGHT VENTRICLE
injury at left sternal border in 4th intercostal space would affect….?
[nipple level]
- skin, subcutis
- pec major
- external intercostal memb
- internal intercostal memb
- internal thoracic artery and veins
- transversus thoracis m.
- parietal pleura
- pericardium
- RV myocardium
posterior surface of heart is mostly which chamber?
LEFT ATRIUM
lateral surface of heart is mostly which chamber?
LEFT VENTRICLE
NE effect in heart
stimulate beta 1 receptors to increase cAMP conc within myocytes
*little effect at beta 2 receptors
dilated CM physiology
- ventricular dilation
- LV systolic dysfunction - decreased vent contractility
*may have sx of CHF
common cause of LV diastolic dysfunction
[impaired filling due to reduced LV compliance]
chronic HTN (hypertensive heart disease). concentric LVH with decrease in chamber size.
also seen with restrictive CM
hypertrophic CM physiology
asymm. septal hypertrophy and dynamic ventricular outflow tract obstruction
what does integrin bind in order for cell adhesion?
fibronectin, collagen, laminin - allow binding to BM and ECM
lipoprotein lipase action
hydrolyze dietary lipids in chylomicrons to release triglycerides
hyperlipidemia type 1
lipoprotein lipase deficiency - increased conc of serum chylomicrons.
hyperlipidemia type 1 SX
(lipoprotein lipase deficiency)
- childhood hyperlipidemia
- pancreatitis, abd pain
- lipemia retinalis
- skin xanthomas
- hepatosplenomegaly
what serum TG conc significantly increases risk of pancreatitis
> 1000 mg/dL
what role does heparin play in lipoprotein lipase activity?
heparin releases endo-bound lipases to encourage clearance of TG from circ
LDL clearance from circ occurs by…?
receptor-mediated uptake by liver
defect in LDL receptor
hypercholesterolemia (high LDL)
hypercholesterolemia SX
(defect in LDL receptor)
- accelerated CAD, chest pain
- tubular (tendon) xanthomas
- maybe xanthelasmas and arcus cornea
what is the hallmark of familial hypercholesterolemia?
tubular (tendon) xanthomas
tubular (tendon) xanthomas
nodular lipid deposits in tendons - Achilles, elbow
enterococcal endocarditis
in elderly men who have undergone GI or GU manipulation (cystoscopy, colonoscopy)
enterococci: Gm pos, gamma hemolytic, cultured in hypertonic saline and bile
adverse effects of direct arteriolar vasodilators
[hydralazine, minoxidil]
reflex symp activation leading to tachycardia and edema (via renin)
how to counteract adverse effects of direct arteriolar vasodilators
coadmin with sympatholytics and diuretics
what layer of heart does SLE affect?
PERICARDITIS - pleuritic chest pain that radiates to neck and shoulders, relieved by sitting up. FRICTION RUB
serosal inflammation
what increases pleuritic chest pain with SLE pericarditis?
inspiration
Libman Sacks endocarditis presentation
heart murmur but otherwise asymptomatic
anticoagulant for pregnant women
heparin (warfarin is teratogenic)
DVT presentation
unilateral leg pain, swelling, warmth.
HOMAN’S SIGN: tenderness of calf muscle on dorsiflexion of foot
DIC is a common complication of….?
- Gm neg bacterial sepsis
- acute pancreatitis
- burn injury
mech of DIC in Gm neg sepsis
activation of coag cascade by bact endotoxins - microthrombi cause microangiopathic hemolytic anemia and thrombocytopenia
DIC labs
increase PT
increase PTT
decrease fibrinogen, V, VIII
what does bleeding from venous puncture sites suggest?
DIC
what is transmural inflamm with fibrinoid necrosis most characteristic of?
PAN (polyarteritis nodosa)
sx of PAN
fever malaise weight loss abd pain melena peripheral neuropathy diffuse aches
what infx is PAN assoc with in 10-30% of cases?
HEP B
what age group does PAN most affect?
young adults
which vasculitis is linked to asthma?
churg strauss syndrome
which vasculitis is linked to antibiotic use?
microscopic polyangiitis (leukocytoclastic angiitis, hypersensitivity angiitis)
which anemia commonly occurs in the setting of chronic alcoholism?
FOLIC ACID deficiency megaloblastic anemia - due to decreased synth of purines, thymidines.
smear: macrocytes, ovalocytes, hypersegmented neutrophils
which nutrient deficiency is more common in alcoholics- B12 or folic acid?
FOLIC ACID!!!
which form of anemia has INCREASED MCHC?
hereditary spherocytosis - mild dehydration of RBC with membrane loss
*spherocytes are smaller in size. cytoplasm stains more intensely
general markers of hemolysis
elevated LDH
reticulocytosis
decreased haptoglobin
most commonly affected protein in hereditary spherocytosis
spectrin
immature T lymphocytes
[thymocytes]
express BOTH CD4 and CD8 cell surf Ags
AND complete TCR or pro-TCR.
exist in thymic CORTEX where they undergo pos selection and in thymic MEDULLA where they undergo neg selection
most common cause of fatigue + new onset murmur in young adult
bacterial endocarditis
which bugs produce endotoxin?
GRAM NEGS
common tumors in Li-Fraumeni syndrome
sarcomas
tumor of breast, brain, adrenal cortex
leukemia
*AUTO DOM p53 mutation- inherit one mutated allele. somatic mutation of second allele needed for tumor development
what does mitochondrial vacuolization indicate?
irreversible cell injury.
mito are permanently unable to generate ATP.
HUS triad
- microangiopathic hemolytic anemia
- acute renal failure
- thrombocytopenia
migratory thrombophlebitis — think ____
CANCER
paraneoplastic hypercoagulability
seen with adenocarcinomas of pancrease, colon, lung – produce thromboplastin-like substance that causes intravasc. coagulation
vit K and celiac sprue
vit K deficiency due to malabsorption - can lead to hemorrhagic diathesis
atrophic gastritis
profound hypochlorhydria.
intrinsic factor deficiency (pernicious anemia).
B12 deficiency.
elevated methylmalonic acid levels.
fomepizole
antidote for suspected methanol (rubbing alcohol) or ethylene glycol (antifreeze) poisoning.
competitive antagonist of alcohol dehydrogenase - prevents conversion of methanol and ethylene glycol into toxic metabolites
prednisone in chemotherapy
induces lymphocyte apoptosis.
contributes to tumor lysis syndrome.
probenicid
increases uric acid excretion in urine.
treat gout, hyperuricemia.
only effective in pts with good renal fx (not for nephrolithiasis or uric acid nephropathy)
increased ferritin seen in….?
- iron overload
2. infx/inflamm (acute phase reactant)
infection in sickle cell pts
at high risk, esp for encapsulated orgs - Strep pneumoniae, H.influenzae
osteomyelitis in sickle cell child
- salmonella**
- S.aureus
- E.coli
prophylaxis for asplenic pts
- penicillin prophylaxis
2. pneumococcal vaccine
fenoldapam
selective dopamine 1 receptor agonist (activates adenylyl cyclase to increase cAMP).
causes art. dilation and natriuresis, leading to decreased systemic vasc resistance and BP
special feature of fenoldapam
ONLY intravenous/parenteral agent that improves renal perfusion.
also increases sodium and water excretion.
beneficial in HTN pts with concomitant renal insufficiency. good for emergency.
main use of esmolol
post operative HTN.
effects rapidly reversed after drug is withdrawn.
what cell directly mediates intimal hyperplasia and fibrosis in response to endo injury?
reactive smooth muscle cells that migrate from media to intima - proliferate, synthesize collagen/elastin/proteoglycans
what is the ONE significant non-enveloped ssDNA virus family?
Parvovirus - parvovirus B19 causing erythema infectiosum, aplastic crises, and hydrops fetalis
what viruses cause bronchitis/bronchiolitis?
all are enveloped, RNA viruses:
influenza A, RSV, coronavirus
underdeveloped area of lymph node in DiGeorge
paracortex - due to mature T cell deficiency
underdeveloped area of lymph node in agammaglobulinemia
primary lymphoid follicles and germinal centers (secondary follicles) - due to absence of B cells
left atrial enlargement can affect which nearby structure?
left recurrent laryngeal nerve - impingement leads to NEURAPRAXIA (failure of nerve conduction due to blunt injury, leading to left vocal cord paresis and hoarseness)
Ortner syndrome
left atrial dilatation sufficient enough to impinge on left recurrent laryngeal nerve.
due to MITRAL STENOSIS.
what is the only intrinsic muscle of the larynx NOT innervated by recurrent laryngeal nn?
cricothyroid m
what process is defective in megaloblastosis?
DNA synth
- ex: folate deficiency
- RNA and protein synth may continue as normal (cytoplasm grows)
pathogenesis of neurotoxicity (peripheral neuropathy) with vinca alkaloid tx
disruption of neuronal microtubules which are responsible for transporting organelles and other cellular products between neuronal cell body and axon terminals
burr cells (RBC)
short evenly spaced projections.
assoc. with uremia, pyruvate kinase deficiency, microangiopathic hemolytic anemia, mech damage
what does left shift of Hb-O2 dissociation curve indicate?
increased Hb O2 affinity (O2 is relatively less available to tissues)-
caused by increased pH, decreased 2,3-DPG, decreased temp.
2,3-DPG (diphosphoglycerate)
organophosphate created in RBCs during glycolysis
conditions that increase 2,3-DPG production
(diminished peripheral tissue O2 availability) hypoxemia chronic lung disease anemia CHF
what is the main enz that degrades 6-mercaptopurine?
xanthine oxidase in liver
what enz activates 6-mercaptopurine and 6-thioguanine (prodrugs)?
HGPRT
