Mix12 Flashcards
What blood vessel can be affected with midgut volvulus?
SMA. During week 6 gut comes out of stomach, rotates, grows, and then comes back into the stomach around week 8-10 of gestation»_space; full midgut rotation. If this rotation is incomplete fibrinous bands (Ladd’s bands) can compress the second part of the duodenum and the mesentery is vulnerable to twisting around the SMA, compromising intestinal perfusion»_space; bowel necrosis.
Presents as bilious vomiting in the first few days of birth.
How does the cause of duodenal atresia differ from jejunal/ileal atresia?
Duodenal atresia = failure to recanalize»_space; double bubble
Jejunal/ileal atresia = disruption of mesenteric vessels»_space; ischemic necrosis»_space; segmental resorption (“apple peel” bowel)
What is an in-frame deletion?
One or more complete codons (triplets) are removed and this doesn’t affect the reading frame of the subsequent codons.
Missesense and nonsense mutations are single BP mut»_space; incorporation of incorrect AA or formation of a premature stop codon (respectively) in the mRNA.
In nonsense mut, protein length is normally shorter and nonfunctional, but the mRNA length is normal.
Are granulomas in sarcoidosis caseating or noncaseating?
Non-caseating.
What are some possible causes of hepatic centrilobular necrosis?
Hepatic centrilobular necrosis = death of hepatocytes surrounding the terminal hepatic vein. Ischemic injury (like R sided HF), drugs, toxins, and fulminant hepatitis can be causes.
What potassium sparing diuretic can also be used as an antiandrogen?
Spironolactone. Can be used in PCOS because of steroid binding abilities, prevents 17,20 desmolase and 17a hydroxylase.
Ketoconazole works as an antiandrogen in a similar mech.
What cell type mediates the destruction of parietal cells in pernicious anemia?
CD4+ T cells mediate parietal cell destruction (autoimmune)»_space; decreased HCl secretion and ^ gastrin production; decreased IF secretion»_space; decreased B12 reabsorption.
Branched chain ketoacidosis is neurotoxic primarily due to elevation of which AA?
Leucine.
- Val and Isoleucine can also be elevated but these aren’t as toxic.
Homocysteinuria is an autosomal recessive disease marked by deficiency of what enzyme?
Cystathionine synthase (B6 dependent)»_space; elevated levels of homocysteine and methionine.
Celiac trunk comes off the aorta and gives rise to what 3 vessels?
- L gastric (esophageal artery comes off this).
- Splenic (L gastroepiploic and splenic artery come off this)
- Common hepatic (proper hepatic, R gastric, and gastroduodenal come off this).
What’s the function of amikacin in preventing bacterial replication?
Amikacin = aminoglycoside (binds 30s and causes misreading of mRNA). * Needs O2 for uptake.
All the ‘mycins’ work this way (neomycin, streptomycin, etc).
What do you do to prevent maternal transmission of strep aglactiae?
Universal screening at 35-37 weeks gestation. Give intrapartum antibiotic prophylaxis to prevent neonatal GBS sepsis, pneumonia, and meningitis.
Clonidine, guanfacine, and a-methyldopa are considered sympatholytics and are used in hypertension because they bind to:
a2 AR
How can you Dx a vWF deficiency with the ristocetin test?
Ristocetin activates Gp1b R on platelets and makes them available for vWF binding to promote clot formation. When vWF is decreased, there is poor platelet aggregation in the presence of ristocetin.
What component of E coli is responsible for development of toxic shock?
Gram neg sepsis is caused by the release of LPS from bacterial cells during division or bacteriolysis. ‘LPS is NOT actively secreted by bacteria’. Lipid A is the toxic component of LPS»_space; activation of Macs which produce the widespread release of IL1 and TNFa that cause the effects of septic shock (fever, hypotension, DIC, etc).
