Q Banks: Week of 02/27/17 Flashcards
A patient has a communication between the atria. How can you tell if it is aplasia of the septum secundum or failure of fusion between the septum secundum and septum primum?
ASD results from aplasia of the septum secundum, while PFO results from failed fusion. ASD can lead to Eisenmenger’s, while PFO just raises risk of emboli.
How can you detect PFO in a bubble study?
Have the patient release a Valsalva maneuver which will increase RA pressure and lead to right-left flow.
What’s the difference between suppression and repression?
Suppression is voluntary and conscious while repression is not.
Explain how telomerases work.
They add TTAGGG repeats to the 3’ end of chromosomes, primarily in stem cells.
(Think, they TAG repeats of 3 –that is, TTA and GGG – to chromosomes.)
Explain how ventilators can be used to lessen cerebral edema.
The brain is able to autoregulate blood flow in the range of 50 mm Hg to 140 mm Hg, so when pressures exceed 140 mm Hg the risk of cerebral edema increases. pCO2 is a potent vasodilator because it indicates heavy usage. As such, increasing ventilator settings to make the patient have slight metabolic alkalosis can decrease cerebral vasodilation and thus decrease the risk of cerebral edema.
The most common leukemia in children presents with what cell surface receptors?
CD19 and CD10
___________ can persist for years after a CNS injury.
Myelin debris
The blood-brain barrier and astrocytes prevent microglia from clearing away myelin. The bodies of oligodendrocytes go away soon through apoptosis.
The rate-limiting step in the synthesis of epinephrine is _____________, while the regulated step is ____________.
tyrosine hydroxylase; PNMT
PNMT is upregulated by cortisol from the zona fasciculata. If you resect the pituitary or damage the adrenal cortex, then PNMT levels will fall.
How can you differentiate arginase deficiency from the other urea cycle defects?
Arginase breaks down arginine to urea and ornithine. (It is the last enzyme in the urea cycle before ornithine re-enters the mitochondria.) Defects in arginase lead to high arginine levels and spastic diplegia.
Uniquely for the urea cycle defects, it does not present with hyperammonemia. The other urea cycle defects, like ornithine transcarbamylase deficiency, present with hyperammonemia and elevated orotic acid.
What does ornithine transcarbamylase do?
It takes carbamoyl phosphate (made from ATP, NH3, and HCO3 in the mitochondria) and adds it to ornithine to make citrulline which gets exported to the cytoplasm and ultimately converted to urea and back to ornithine.
IRS mediates the ____________ effects of insulin, whereas PI3K mediates the ____________ effects.
nuclear transcription and cell growth; anabolic and glucose lowering
What is the best approach to a patient demanding medically unnecessary treatment (such as a patient demanding antibiotics for a likely viral illness)?
Acknowledge the patient’s concerns, explain that that treatment might be harmful, and offer other treatments (such as relief of symptoms).
What does a bright border on the gallbladder in a CT indicate?
Porcelain gallbladder: a complication of chronic cholecystitis that presents with calcification
This increases the risk of gallbladder adenocarcinoma.
Describe the most classic presentation of inflammatory breast cancer.
Inflammatory breast cancer invades lymphatic tissue and so causes lymphadenopathy in the axilla (most often). It causes a rash that is characteristically rough, indurated, and itchy.
True or false: a two-year-old who has 40 words but only uses one at a time is within normal limits.
False. At two, children should have between 50 and 200 words and should be able to make two-word sentences.
The inferior epigastric branches off ____________, while the superficial epigastric branches off ____________.
of the external iliac superior to the inguinal ligament; of the femoral artery inferior to the inguinal ligament
Other than the inferior epigastric, what artery branches off of the external iliac?
Deep circumflex iliac
People with trochlear nerve palsy have diplopia when looking _____________.
down (because the trochlear nerve innervates the superior oblique)
True or false: the spleen is a retroperitoneal organ.
False.
Suprarenal glands (adrenal glands) Aorta Duodenum (except 1st part) Pancreas Ureter and bladder Colon (ascending and descending) Kidneys Esophagus Rectum
Which of the following indicates irreversible cell injury?
• Polysomal disaggregation
•Mitochondrial swelling
•Clumping of nuclear chromatin
•Mitochondrial vacuolization
•Disaggregation of granular elements in the nucleus
Mitochondrial vacuolization
Mitochondria can swell reversibly, but if they are true vacuoles then they cannot make ATP and the cell will die.
The rest of the findings are normal.
CD14 is a marker of _______________.
macrophages
What does stimulation of alpha-1 receptors do to the eye?
Mydriasis
Looking at a graph of pulse pressure, how can you differentiate norepinephrine from dobutamine?
Norepinephrine presents with elevated systolic and diastolic pressures, while dobutamine presents with elevated systolic pressure (B1) and decreased diastolic pressure (B2).
Morphine binds to a ____________ receptor.
Gi
This leads to increased K efflux and decreased Ca influx.
ST elevations in aVL and I indicate blockage of ____________.
the left circumflex artery
Capillary wall thickening in the glomerulus is characteristic of which disorder?
Membranous nephropathy
Explain the embryology of the pancreas.
The dorsal and ventral pancreatic buds arise from the duodenal portion of the foregut. The ventral portion rotates 270º around (to the right first and then back around to the left side of the body) and fuses with the dorsal bud. The dorsal bud is larger and gives rise to the tail, body, and head of the pancreas. The ventral bud is smaller and gives rise to the uncinate process and main duct.
A neonate has an intracranial bleed. You’re trying to figure out what might have contributed. How can you decide if vitamin K deficiency or germinal matrix fragility is more likely?
The germinal matrix involutes around 28 weeks gestation and is thus a problem for premature infants. Neonatal vitamin K deficiency presents in those born at home because vitamin K is given to babies born in hospitals; the clotting deficiency can persist for up to one month after birth.
What is the membrane potential of chloride?
- 75 mV
What is the membrane potential of calcium?
+ 125 mV
What does ANP do?
- Induces natriuresis
- Relaxes arteries
- Restricts the secretion of aldosterone
True or false: ketone generation is used to maintain blood glucose from 30 hours of fasting on.
False. Ketones are themselves used to generate acetyl-CoA and cannot make glucose.
Glycogenolysis maintains blood glucose for the first 12 hours and then gluconeogenesis maintains it after that.
How long must the SIGECAPS criteria be present to qualify as major depression disorder?
Greater than 2 weeks
What’s the difference between persistent depressive disorder and major depression disorder?
PDD is MDD that has lasted for more than two years.
Adjustment disorder with depressed mood is ________________, compared to MDD.
less severe
Recurrent ____________ are suggestive of sickle cell anemia.
abdominal and bone pain
What are some clinical symptoms of PKD?
- Hypertension
- Hematuria
- Flank pain
“Infiltration of the [intestinal] lamina propria with atypical lymphocytes” describes what condition?
MALT lymphoma
Keloids result from overexpression of what cytokine?
TGF-beta
If you injure the nerve that passes through the popliteal fossa, what motor and sensory deficits are you likely to have?
Lesions of the tibial nerve in the popliteal fossa will lead to loss of the following:
•Motor: plantarflexion and inversion
•Sensory: plantar surface of the foot, lateral surface of the foot, and posterior calf
The ____________ dermatome covers the anterior surface of the knee.
L4
Which two dermatomes cover the posterior leg?
S1 (lateral) and S2 (medial)
The Romberg test stresses the patient’s ______________.
proprioception
Why does left-heart failure lead to dyspnea?
The increased fluid present in the pulmonary veins leads to increased fluid in the lung interstitium. That amount of extra fluid decreases the lung compliance and can mimic restrictive lung disease.
A patient undergoes a cardiac stress test. While resting, his QRS is normal duration. At near-maximal heart rate, however, his QRS is prolonged. What class of drug is he likely taking for his atrial fibrillation?
IC
All of the class I drugs can prolong the QRS complex, particularly in a use-dependent manner.
Three genetic mutations can caue pheochromocytoma: _______________.
RET, VHL, and NF-1
Three children have the same genetic disorder. One of them, however, has it more severely than the others. What principle can likely explain this?
It could be two things:
- The disorder might have variable expressivity.
- Heteroplasmy: there are many mitochondria in an ovum. Some may be affected while others aren’t. All children of an affected mother will be affected, but some may be less affected if they inherited fewer mutated mitochondria.
What kind of protein does hydrochlorothiazide inhibit?
NaCl cotransporter that generates a gradient that pulls calcium into the interstitial fluid.
Migraines result from ____________ sumatriptan causes _______________.
vasodilation; vasoconstriction (from 5-HT1b agonism)
What does agonism of 5-HT1b (by sumatriptan) cause?
Decreased release of vasoactive peptides
The dexamethasone suppression test tells you if ______________.
the ACTH-secreting tumor is in the pituitary –in which ACTH will be suppressed –or ectopic –in which ACTH won’t be suppressed
Yellow-brown pigment in the cardiac myocytes of a 78-year-old likely are ___________.
lipofuscin (peroxidized lipids)
Glioblastoma multiforme arise from ____________.
astrocytes
In addition to central necrosis and palisading cells around the periphery, glioblastoma multiforme presents with _____________.
vascular proliferation
Mutations in ___________ cause early adenomas (in the colon) to mature into late adenomas, while mutations in __________ promote the transition to carcinoma.
KRAS; p53
Mutations in APC/beta-catenin promote ____________.
development of early adenomas (while KRAS and p53 are later)
Myofibroblasts and matrix metalloproteases might be present in what kind of wound healing stage?
Contracture
Note: MMPs although for tissue remodeling and for making space for myofibroblasts.
Psoriasis presents with a thin or absent stratum ________.
granulosum
What cells might be present in the tissue of someone with psoriasis?
Neutrophils (attracted from the T cells)
What is an important concept to know regarding cilia and glands in the airway?
The airway is set up to prevent the accumulation of mucus in the alveoli. As such, cilia continue past ALL of the epithelial glands so that they can catch any mucus that slides down.
The cilia extend through the terminal bronchioles.
What does withdrawal from cocaine and the other amphetamines look like?
- Hypersomnia (because they weren’t sleeping)
- Hyperphagia (because stimulants are appetite suppressants)
- Depression (crashing)
- Vivid dreams
Note: withdrawal from cocaine does not produce specific physical signs (as in the cases of alcohol and opiate withdrawal)
Describe pyruvate kinase deficiency.
Pyruvate kinase (which converts PEP to pyruvate and generates one ATP) is important in the maintenance of RBCs because they do not have mitochondria. Patients with this will thus have lots of hemolysis and expanded RBCs.
Why does the spleen expand in hemolytic disorders?
If the reticuloendothelial cells are forced to work extra (as they would in a patient with pyruvate kinase deficiency), then they undergo hyperplasia. Specifically, the red pulp undergoes hyperplasia.
What protein disassembles viral glycoproteins for expression in MHC I receptors?
Ubiquitin and proteasomes
Areas of necrosis in the brain will usually be repaired by ______________.
glial hyperplasia
Describe what levels of posterior rib fractures can lead to liver, spleen, and kidney lacerations.
- Spleen: left 9, 10, and 11 (“spleEN = tEN”)
- Kidneys: left and right 12
- Liver: right 9, 10, and 11
Explain the biochemical mechanism of how the intestines inhibit acid secretion.
The arrival of food in the intestines leads to release of peptide YY which binds to the enterochromaffin-like cells. ECLs usually secrete gastrin, but PYY inhibits this.
What is lobar sequestration?
A congenital lung malformation in which lung tissue does not communicate with the airway
What is a key inhibitory molecule in beta-oxidative metabolism?
Malonyl-CoA
Think about it: malonyl-CoA represents the anabolic production of fatty acids. Thus, having this molecule inhibit carnitine acetyltransferase –which takes fatty acids from the cytoplasm to the mitochondria –serves to prevent the breakdown of newly formed fatty acids in the cytoplasm.
How can aortic dissection lead to discrepancies in the BP of the left and right arms?
Aortic dissection leads to bleeding around the artery. The hematoma can put pressure on arteries and even occlude whole branches. Thus, a dissection in the ascending aorta can lead to occlusion of the brachiocephalic trunk and thus low BP in the right arm.
Aortic dissections are acutely caused by ___________.
tears in the intima
True or false: medical calcific stenosis can lead to aortic dissection.
False. Generally, medial calcific stenosis leads to hypertension due to arterial inflexibility.
What is the greatest risk factor for aortic dissection?
Hypertension
In a positively skewed plot, the mean is _________ the mode.
greater than
In an older patient, _________________ should be included in the hospital admission process.
discussion of advanced directives
The extrahepatic symptoms of HBV are said to be ___________.
serum-sickness like (as in arthralgia, fever, lymphadenopathy, and kidney issues)
What is the effect of nitroprusside?
It is a balanced venous and arterial vasodilator. As such, it decreases preload and afterload and roughly maintains stroke volume.
In which patients is pO2 the dominant driver of respiration?
Those with COPD
People with COPD have chronic hypercapnia and thus become desensitized to pCO2. Also, they’re more likely to have extreme hypoxemia and have their respirations driven by pO2.
Pulmonary stretch receptors and C fibers sense _______________.
the degree of expansion and thus they control how much the lungs expand in normal breathing
The carotid bodies (mediated by which nerve?) sense _______________.
H+, pO2, and PCO2
The nerves are mediated by the glossopharyngeal nerve.
Explain the mechanisms of hypercalcemia in multiple myeloma.
- MM directly metastasizes to the bone and causes the release of calcium, thereby raising serum calcium levels.
- Because the PTH system is still intact, PTH is suppressed.
- Amyloid cast nephropathy leads to kidney damage.
- The kidney damage and low PTH leads to low vitamin D.
- PTHrp is not present.
- Low PTH and hypercalcemia lead to increased urinary excretion of calcium.
True or false: carvedilol should not be used in systolic heart failure due to vasodilatory effect.
False. It is safe and recommended in SHF.
What is a normal post-void residual urine volume?
50 mL or less
To what action potential value does QT prolongation correspond?
Lengthening of the phase 2 plateau
As such, drugs that prolong the plateau –such as class IA antiarrhythmics and the class III drugs – can lead to QT prolongation.
How might you hear torsades de pointes described?
As “polymorphic QRS complexes of varying amplitude and duration”
The hallmark histologic sign of acute viral hepatitis is _________________.
hepatocyte necrosis with ballooning degeneration
True or false: chlordiazepoxide should not be used to treat delirium tremens because of its long half-life.
False. It is preferred because of its self-tapering effect. Caution: do not use in patients with liver failure.
