things I've gotten wrong Flashcards
alkaptonuria
homgentisate oxidase deficiency that leads to a buildup of homogentisic acid (it can’t be converted to maleylacetoacetic acid). patients have dark CT, brown pigmented sclera, debilitating arthralgias. urine turns black.
normal vaginal pH`
4-4.5
compare roseola, parvovirus B19, and rubella
roseola: HHV-6. causes a HIGH fever (>104), rash that begins on trunk and spreads). rash starts as fever wanes.
parvovirus B19: low grade or no fever, starts all of a sudden, may be itchy, often starts on extremities
rubella: generalized LAD; rash starts on face and spreads down. lasts about 5 days.
measles: koplik spots, cough, conjunctivitis. rash starts on face.
isotretinoin
aka accutane. synthetic cis isomer of ATRA (vitamin A derivative). used for severe acne. teratogenic- causes cleft palate and cardiac abnormalities. inhibits follicular epidermal keratinization- loosens keratin plugs of comedones and facilitates their expulsion. reduces the size of sebaceous glands and inhibits sebum production
ristocetin
test used for von Willebrand disease
activates the GpIb receptor on platelets and makes them available for vWF binding. when vWF is decreased, there is poor platelet aggregation in the presence of ristocetin.
daptomycin
drug used for highly resistant gram positive bacteria (MRSA). punches holes in the bacterial membrane. toxicities: elevated CK and myopathy.
it is inactivated by pulm surfactant, so it can’t be used for pneumonia.
foramen rotundum and foramen ovale and foramen spinosum in the skull
foramen rotundum: CNV2 exits
foramen ovale: V3, lesser petrosal nerve, accessory meningeal artery, emissary veins.
(foramen spinosum has the middle meningeal artery and vein nad the recurrent/meningeal branch of CNV3
What should I know about tricuspid endocarditis in IV drug users? (common bugs, presentation, complications
S. aureus, P. aeruginosa.
presents as high fever, fatigue, dyspnea.
can cause pulmonary red infarcts because of septic embolization from the tricuspid valve to the pulm artery.
describe the regulation of cerebral perfusion
cerebral perfusion is primarily driven by PCO2 as long as BO is 60-140 mmHg. an incr. in PCO2 will cause a linear increase in cerebral blood flow, and a decr. in PCO2 will cause a linear decrease in cerebral blood flow (patients with cerebral edema may benefit from hyperventilation to decrease CO2 and decrease blood flow to brain).
O2 only begins to impact cerebral blood flow when if falls below 50.
Note that hyperventilation will increase O2.
aspergillis vs. mucor and rhizopus
aspergillis: acute angle branching, multicellular hyphae. can cause invasive aspergillosis (immunocompromised, chronic granulomatous disease- problem seen with neutropenia). lung is most commonly affected area; pts have hemoptysis and lung granulomas. will spread hematogenously. septate hyphae. often cuases infarcts in skin, paranasal sinuses, kidneys, heart, and brain.
Can also grow as aspergillomas in old lung cavities. in pts with asthma aspergillis can cause allergic bronchopulmonary aspergillosis- wheezing and migratory pulm infiltrates. incr. IgE and incr. abs against aspergillis. tx is steroids for astham aspergillosis.
mucormycosis: seen in ketoacidotic diabetc or leukemic pts. they proliferate in the blood vessel walls when there is excess ketones and glucose, penetrate the cribiform plate, and enter the brain. may cause frontal lobe absceses. nonseptae, broad angles. headache facial pain, necrotic eschar.
conditions associated with anal atresia
most common condition: urinary tract defects. Without any other known defects, this is the most likely.
anal atresia can also occur as part of VACTERL, a much rarer problem with mesoderm. VACTERL: vertebral defects, anal atresia, cardiac abnormalities, tracheoesophageal fistula, renal defects, limb defects (bone and muscle).
What happens during transcription when the ribosome comes across a stop codon?
releasing factor 1 recognizes it, and stimuates the release of the formed polypeptide chain
describe the anatomy needed to perform a safe thoracentesis
lower border of the pleura:
right: 7th rib in midclavicular line, upper border of the 10th rib in midaxillary line, and 12th rib in the paravertebral line.
left: 7th rib in the mid clavicular line, lower border of the 10th rib in the midaxillary line, and the 12th rib in the paravertebral line.
lower border of the lung is 2 intercostal spaces above the lower border of the pleura. So, for example, in the midaxillary line, insert the needle between the 7th and 9th rib. below the 9th rib, you run the risk of puncturing the liver on the right
What are kussmaul’s sign and pericardial knock
kussmaul sign: paradoxical incr. in JVP with inspiration. usually seen in pts with chronic constrictive pericarditis, a condition that takes months-years to develop. DDx includes restrictive cardiomyopathy, severe right sided heart failure, tricustpid stenosis, (tamponade).
pericardial knock: brief, high freq. precordial sound heard in early diastole (after S2) in pts with constrictive chronic pericarditis. occurs earlier than the S3 gallop and may be confused with the opening snap of mitral stenosis. requires months-years to develop
