Flashcards in test #10 3.24 Deck (136)
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
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.
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
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.