Mix13 Flashcards
Metanephric mesoderm gives rise to which structures of the kidney?
Metanephric mesoderm = metanephric blastema = gives rise to glomeruli, bowman space and all structures until DCT.
Metanephros (ureteric bud) derived from caudal part of mesonephric duct gives rise to everything else (collecting duct»_space; ureter, etc)
Vast majority of cases of Down syndrome happened due to nondisjunction during:
maternal meiosis I
Drug of choice for syphilis
penicillin
Universally sensitive because they are all g- with a peptidoglycan wall.
Rx of choice for bacteroides fragillis infection:
Bacteroides = g- anaerobic rod that produces b-lactamase, so combination of extended spectrum penicillin (i.e. piperacillin) and a b-lactamase inhibitor (tazobactam, clavulnic acid, or sulbactam) is best
Thoracic outlet syndrome»_space; compression of the brachial plexus by what structure?
Scalene triangle.
can also cause compression of subclavian artery (exertional arm pain) and subclavian vein (upper arm swelling)
Porphyria cutanea tarda is due to deficiency of what enzyme
uroporphyrinogen decarboxylase»_space; ^ uroporphyrinogen.
Causes blistering photosensitivity and hyperpigmentation. Autosomal dominant, worse with EtOH
Porphyrinogens react with O2 on excitation by UV light and cause photosensitivity rxns.
What do the d loop and t loop do in tRNA?
D loop has dihydrouridine residues and helps facilitate correct tRNA recognition by the proper aminoacyl tRNA synthetase.
T loop is needed for binding tRNA to ribosome. Has ‘TYC’ (ribothymidine, pseudouridine, and cysteine)
Bipolar I vs Bipolar II
Bipolar I = manic episode(s). Depressive episodes common but not required.
Bipolar II = hypomanic episode(s). Major depressive episodes required.
What part of the heart forms the cardiac apex (PMI)?
Left ventricle forms the apex of the heart.
Why do you get syndham chorea with strep pyogenes infection?
autoab (molecular mimicry) to myosin and n-acteylbeta-d-glucosamine (lysoganglioside, a neuronal cell surface protein) provide the cardiac and neurologic manifestations
How does hypertriglyceridemia lead to acute pancreatitis?
high circulating triglycerides»_space; ^ production of free FA due to activity of LPL in the pancreatic capillaries. These free FA are normally bound to albumin, but if this exceeds binding capacity the free FA can cause direct damage to pancreatic acinar cells.
What’s the major mechanism of pathogenesis for shigella?
Mucosal invasion through M cells. this is the main pathogenesis (shiga toxin plays a minor, nonessential role).
After invasion, it escapes phagolysosome and then uses host cell actin to go to other cells.
Equation for vol of distribution:
Vd = amount of drug given (mg)/plasma [ ] of drug (mg/L)
TBW is 41 L, plasma vol = 4.5L
What’s the mech of using thiazolidinediones in DM patients/
Thiazoledinidiones bind PPAR-g (a transcriptional activator) to promote increased sensitivity to insulin, similar to fibrates. (TZD does not promote insulin release, sulfonylureas and meglitinides do this).
PPARg activation promotes expression of GLUT4 and adiponectin (increases # of insulin responsive adipocytes and stimulates FA oxidation)
Inheritance pattern of G6P Deficiency:
X linked recessive
