test #10 3.24 Flashcards
major component of pulmonary surfactant? released triggered by?
dipalmitoyl phosphatidylcholine; calcium dependent fusion of lamellar body membrane w/ type II pneumocyte cell membrane.
what can cause bronchoconstriction (5)?
(1) alveolar hypocapnia, (2) bronchial inflammation, (3) parasympathetic (cholinergic) (4) efferent nerve activity, and (5) inhaled / aspirated irritants
bladder carcinomas are often (1)? which (2) are possible, but rare?
urothelial (transitional cell) carcinomas compose 90% of malignant bladder neoplasms. squamous cell and adenocarcinomas are rare.
classic presentation of bladder carinoma
painless gross hematuria. mass grows as papillary or sessile mass.
diagnosis of bladder carcinoma
cystoscopy
squamous cell carcinoma of bladder is associated with..
rare; associated w/ schistosoma haematobium infection
best predictor of malignant potential of bladder carcinoma?
tumor stage / penetration of bladder wall
biotin serves as..
CO2 carrier on surface of carboxylase enzyme. (encompasses enzymatic subtypes acetyl-CoA carboxylase [ACC], pyruvate carboxylase [PC], propionyl carboxylase [PCC], beta-methylcrotonyl CoA carboxylase). important in carbohydrate and lipid metabolism.
biotin deficiency can cause what two metabolic derangements
(1) metabolic acidosis: in tissues responsible for gluconeogenesis, pyruvate carboxylase (and biotin) is needed for conversion of pyruvate to oxaloacetate. in deficiency, pyruvate levels rise and converted to lactic acid instead. (2) fatty acid excess: propionyl CoA carboxylase (and biotin) needed to synthesize succinyl CoA from amino acids like valine. biotin-deficient –> propionyl CoA builds up and instead metabolized into surplus of odd-chain fatty acids.
biotin deficiency results from.. (3)
poor diet, excessive raw egg white consumption (high levels of biotin-binding avidin in egg whites) and congenital disorders of biotin metabolism
delayed puberty + anosmia
Kallmann syndrome. failure of GnRH neurons to migrate from origin in olfactory placode (situated outside CNS) to normal anatomic position in hypothalamus. will have some pubic hair bc normal adrenarche occurs normally
mutation in Kallmann syndrome (2)
KAL-1 gene or the FGFR-1 gene (required for GnRH neuron migration)
US definition of delayed puberty in boys & girls
absence of incomplete development of secondary sexual characteristics by 14 in boys and 12 in girls.
first sign of puberty in boys? girls?
testicular enlargement in boys. breast enlargement in girls.
megaloblastic anemia w/ peripheral neuropathy
cobalamin deficiency. (folate alone cannot cause peripheral neuropathy)
usage of folate alone w/ B12 deficiency?
can moderately improve hemoglobin levels, but will worsen demyelination & abnormal myelin synth by depleting concentration of unmethylated cobalamin available for methymalonyl-CoA processing.
high dose folate can have what drug interaction
may antagonize phenytoin
major cause of abdominal aortic aneursym?
atherosclerosis. intimal fatty streaks –> progress enough to weaken underlying media of aortic wall.
intimal fatty streaks
earliest lesion of atherosclerosis – intimal lipid-filled foam cells, derived from macrophages and SMCs that have engulfed LDL.
medial degeneration
characterized by fragmentation of elastic tissue and separation of the elastic and fibromuscular components of tunica media by small, cleft-like spaces. less common than atheroscerlosis
medial inflammation
results in arteritis (i.e. giant cell or takayasu). can promote aortic aneursym, but rare
dense periaortic fibrosis w/ inflammatory reaction
unusual variant of abdominal aortic aneursym, rich in lymphocytes, plasma cells, macrophages, and often giant cells. unclear cause.
squamous cell carcinoma of the anus
pain, itch, rectal bleeding, visible ulcerative mass. linked to HPV infection w/ 16 and 18.
reactivation of EBV in HIV+ can manifest as.. (2)
(1) non-hodgkin’s lymphoma and (2) oral hairy leukoplakia [white plaques on lateral tongue margins]
presentation of lymphogranuloma venereum
ulcerative / vesicular lesion on external genitalia –> regional PAINFUL lymphadenopathy. could have proctitis w/ tenesmus and bloody discharge. not common.
aortic dissection A vs. B
type A: any portion of the ascending aorta. type B: descending aorta.
aortic dissection blood pressure discrepancy?
as dissecting intramural hematoma spreads along aortic wall can compress major arterial branches
primary risk factor for aortic dissection. describe pathogenesis
hypertension (medial hypertrophy of aortic vasa vasorum, consequently, reduced blood flow to aortic media. can cause medial degeneration w/ loss of smooth muscle cells –> aortic enlargement and increased wall stiffness. exacerbate aortic wall stress. synergistic increase in aortic WALL STRESS greatly increases risk of INTIMAL tearing & blood entering dissect through MEDIA.
monckeberg sclerosis (medial calcific sclerosis)
form of arteriosclerosis characterized by calcific depositis in MEDIAL layer of MUSCULAR arteries. usu pts > 50y/o. can cause isolated systolic HTN due to arterial hardening.
severe megaloblastic anemia precursors
90% of erythroid precursors are destroyed w/o ever entering circulation. bone marrow is hypercellular
can peripheral neuropathy in B12 deficiency occur in the absence of frank anemia?
YES! and folate can make neuro symptoms worse.
MCV > 100 fL? MCV > 110?
MCV > 100 can be seen with liver disease, hypothyroidism, alcoholic liver disease, and B12/folate def. MCV > 110 typically only seem w/ B12 and folic acid deficiency.
consumption of fish in japanese restaurant? symptoms? rx?
think pufferfish – TTX ingestion (block voltage-gated sodium channels) symptoms: dizziness, weakness, loss of reflexes, paresthesia of face and extremities, nausea, vomiting, diarrhea, severe hypotension, general paralysis, death. rx: supportive care & intestinal decontamination w/ gut lavage and charcoal.
what are 4 toxins that block voltage gated Na+ channels? by what mechanism?
(1) tetrodotoxin (puffer-fish) (2) saxitoxin (dinoflagellates in “red tide”) —-> 1 & 2 bind Na+ channels and inhibit Na+ influx, preventing AP conduction.
(3) ciguatoxin (exotic fish, Moral eel) (4) batrachotoxin (south american frogs) —–> 3 & 4 bind to Na+ channels and deep open, causing persistent depolarization.
power. positively correlated with what?
the probability of seeing a difference when one truly exists (1-beta) beta = probability of being blind to a true difference. power is positively correlated w/ SAMPLE SIZE
foamy, frothy urine caused by.. (2)
proteinuria or bile salts in urine
most common cause of coronary sinus dilatation?
elevated right-sided heart pressure secondary to pulmonary artery HTN. usu coronary sinus is not visible.
5 causes of accelerated bone loss (which can lead to pathological fractures)
(1) hyperprolactinemia –> hypogonadism (2) hyperparathyroidism (3) hyperthyroidism (4) chronic glucocorticoid excess (5) vitamin D deficiency
stomach ulcers can occur w/ which 2 things?
(1) isolated hyperparathyroidism or (2) Zollinger-Ellison syndrome
purposeless extremity movement w/ restlessness 3 months after a sore throat?
Sydenham chorea (most common acquired chorea of childgood, sole neurologic manifestation of acute rheumatic fever) hyperkinetic extrapyramidal movement disorder.
sydenham chorea caused by… abs?
CNS autoimmune reaction precipitated by group A beta-hemolytic strep throat after 2-3 month latency. anti-neuronal antibodies binding to caudate and subthalamic nuclei.
chronic rheumatic heart disease
mitral and aortic valve involvement
major and minor jones criteria for diagnosis of acute rheumatic fever
2 major. or 1 major & 2 minor. major: polyarthritis (joint), carditis, subcutaneous nodules, erythema marginatum, sydenham chorea. minor: fever, arthralgia, elevated acute-phase reactants (ESR or CRP), prolonged PR
polyarthritis in acute rheumatic fever
migratory & transient. rarely, if ever, deforming!
3 ways kidney corrects disturbances in acid-base balance
- excess H+ excreted 2. bicarbonate recycled [carbonic anhydrase in proximal tubule lumen combines H+ & HCO3- —> H2CO3 —> H20 and CO2 (reabsorbed by epithelial cells) –> in cell, H2O and CO2 rejoin to make H2CO3, which dissociates into H+ and HCO3-. HCO3- is reabsorbed, H+ is returned to lumen. 3. titratable acids are excreted {limit to urinary excretion of free H+ (pH 4.5), some H+ is bound by HPO4- and NH3 to form titratable acids H2PO4- and NH4+. allows for excretion of acid w/o rapid decrease in urinary pH
minimum urinary pH
limit to urinary excretion of free H+. pH = 4.5
stab in left sternal border, fourth intercostal space (level of nipple)
(1) skin and subcutis (2) pectoralis major muscle (3) external intercostal membrane (4) internal intercostal muscle (5) internal thoracic artery and veins (6) transversus thoracis muscle (7) parietal pleura (8) pericardium (9) right ventricular myocardium
how could one stab the IVC?
stab wound to the back immediately to the right of the vertebral bodies
most common inborn error of methionine metabolism?
homocystinuria
presentation of homocystinuria
present at 3-10y w/ ectopia lentis (dislocated lens). about 1/2 experience intellectual disability. marfanoid habitus (elongated limbs, arachnodactyly, scoliosis) and osteoporosis. high risk for thromboembolic episodes involving both large and small vessels (esp brain, heart, and kidney).
major cause of morbidity and mortality in homocystinuria?
thromboembolism
most freq cause of homocystinuria?
deficiency in cystathione synthetase (requires pyridoxine B6 as a cofactor).
rx for homocystinuria
many respond dramatically to pyridoxine B6 supplementation (improves residual enzymatic activity and reduces plasma homocysteine levels) & restriction of methionine. methionine cycle.
vitamin K is involved in..
post-translational conversion of glutamate to gamma-carboxyglutamic acid. modification needed for many clotting factors & regulatory proteins in coagulation cascade.
