Flashcards in 4 Deck (51)
A type 2 diabetic with a HgbA1c of 10% presents to your clinic with many complaints. You are concerned about the effect of the patient’s long-term hyperglycemia. What diabetic complications can be attributed to sorbitol-induced osmotic damage? Which enzyme converts glucose to sorbitol? (FA15 p104) (FA16 p92)
aldose reductase converts glucose-->sorbitol
sorbitol dehydrogenase converts sorbitol to fructose
lack of sorbitol dehydrogenase-->buildup:
osmotic damage: cataracts, retinopathy, and peripheral neuropathy (damage to Schwann cells) seen with chronic hyperglycemia in diabetes
2 mechs of destruction in DM:
glycosylation of BVs
sorbitol induced osmotic damage
Which efferent fibers carry input from the brain that influences the outer hair cells (OHCs) of the cochlea in much the same way that gamma motor neurons influence muscle spindles? What is the result of this input? What is the result of damaging the OHCs (as with antibiotics such as gentamicin and streptomycin)?
olivocochlear bundles: contraction of outer hair cells-->stiffing of basilar membrane in cochlea-->sensitizes inner hair cells to particular frequency
damage of OHCs results in wide deflection of basilar membrane (vs. sharp)-->hearing loss
What is type II (β) error? (FA15 p54) (FA16 p38)
not finding a result that is actually there
Stating that there is not an effect or difference when one exists (null hypothesis is not rejected when it is in fact false)
A child in India is brought to the doctor with symptoms of muscle weakness, malaise, headache, fever, and hyporeflexia. For the past few weeks, he had been swimming in a waterway known to contain sewage. You think this boy has contracted a pathogen via the fecal-oral route. Which area of the body is this pathogen attacking to give the neurologic symptoms seen? (FA15 p471) (FA16 p474)
polio virus: destruction of cells in anterior horn of SC-->LMN signs
What are the risk factors for osteosarcoma? (FA15 p428) (FA16 p429)
Paget disease of bone, bone infarcts, radiation, familial retinoblastoma, Li-Fraumeni syndrome (germline p53 mutation), male sex, age 10-20 yrs
(2nd most common 1o malignant bone tumor after multiple myeloma)
What disorders can cause cotton-wool spots on the retina?
pale areas, infarcts of nerve fiber layer of retina
causes: chronic HTN, DM retinopathy, AIDS, Lutus, Temporal giant cell arteritis, Wegener's, polyarteritis nodosa
Which cardiac valve is most commonly involved in infective endocarditis and acute rheumatic fever?
(FA15 p298-299) (FA16 p293-294)
Tricuspid in IVDU (venous return)
Name the syndromes below that are common causes of anovulation. (FA15 p323, 585) (FA16 p317, 591)
elevated cortisol, central obesity
amenorrhea + hirsutism + obesity
elevated cortisol, central obesity: Cushing's syndrome
amenorrhea + hirsutism + obesity: PCOS: Polycystic ovarian syndrome (Stein- Leventhal syndrome)
PCOS: Hyperinsulinemia and/or insulin resistance hypothesized to alter hypothalamic hormonal feedback response-->^^LH:FSH ^androgens from theca interna cells, dec. rate of follicular maturation-->unruptured follicles (cysts) + anovulation
Which neurotransmitters in the brain are affected in each of the following disorders? Are the levels increased or decreased? (FA15 p507) (FA16 p511)
Alzheimer disease Huntington disease
Parkinson disease: decreased dopamine, ^^ACh, ^^serotonin
Alzheimer disease: dec. ACh, ^^glutamate
Huntington disease: dec. GABA, dec. ACh, ^^dopamine,
Anxiety: ^^NE, dec. serotonin, dec. GABA
Depression: dec. NE, dec. dopamine, decreased serotonin
Huntington's and Parkinsons are close to opposites
tx schizo (trying to dec. dopamine) can induce parkinsonism: opposite dopamine fluctuations
What is the underlying cause of DiGeorge syndrome? What are the manifestations of DiGeorge syndrome? (FA15 p88, 214, 566) (FA16 p76, 208, 570)
thymic aplasia: 22q11 deletion; failure to develop 3rd and 4th pharyngeal pouches-->absent thymus and parathyroids.
hypoPTH, hypocalcemia (tetany), recurrent viral/fungal infections (T-cell deficiency), conotruncal abnormalities (e.g., tetralogy of Fallot, truncus arteriosus)
absent thymic shadow on CXR
may see cleft palate, abnormal facial features
Which immune response is responsible for hyperacute, acute, and chronic transplant rejection? What is the time frame for each? (FA15 p217) (FA16 p211)
hyperacute (w.in minutes): Pre-existing recipient antibodies react to
donor antigen (type II HSR), activate complement
acute (weeks-mos): Cellular: CD8+ T cells activated against donor MHCs. Humoral: similar to hyperacute, except antibodies develop after transplant.
chronic (mos-yrs): CD4+ T cells respond to recipient APCs presenting donor peptides, including allogeneic MHC.
Both CMI and Hum.
What is the treatment for digoxin toxicity? (FA15 p257) (FA16 p251)
digoxin immune Fab fragments
For which infections is vancomycin a good choice? How does vancomycin resistance develop? (FA15 p183) (FA16 p173)
G+, serious MDR: MRSA, S. epidermidis, ensitive Enteroccocus species, and C. diff (oral dose for pseudomembranous colitis)
resistance: amino acid modification of D-ala D-ala to D-ala D-lac.
“Pay back 2 D-alas (dollars) for vandalizing (vancomycin).”
Do atypical antipsychotics primarily address the negative or positive symptoms of schizophrenia? How does the mechanism of action of typical antipsychotics differ from the mechanism of action of the atypical antipsychotics? (FA15 p509, 521) (FA16 p514, 525)
Schizophrenia—both positive and negative symptoms
atypical MOA: Not completely understood. Varied effects on 5-HT2, dopamine, and α- and H1-receptors
All typical antipsychotics block dopamine D2 receptors (^^[cAMP]).
atypicals: Olanzapine, clozapine, quetiapine, risperidone, aripiprazole, ziprasidone.
"It’s atypical for OLd CLOZets to QUEITly RISPER from A to Z."
A 67-year-old man with new-onset hepatic failure and normal renal function is currently taking a drug metabolized and excreted by the kidneys. Would you need to change the loading dose or maintenance dose of this medication because of this hepatic failure? If this patient were to develop hepatorenal failure, would you need to change the loading dose or maintenance dose of the medicine? (FA15 p243) (FA16 p237)
decrease the maintenance dose, not loading dose if hepatorenal failure, not nec. to adult in hepatic failure
What substances compose the matrix of the bone?
70% crystalline salts: Ca2+, phos, hydrapatite, conjugated ions, Na+, Mg++
30% organic: collagen, chondroitin sulf. hyaluronic acid
While thiazide and loop diuretics are known for wasting potassium in the urine, there are other diuretics that conserve it. Which diuretics are these? What are their mechanisms of action? What are their important side effects? (FA15 p554) (FA16 p558)
aldosterone antagonists: spironolactone, epleronone
Na+ channel blockers: triamterene, amiloride
-both work at cortical collecting tubule
SEs: Hyperkalemia (can lead to arrhythmias), endocrine effects with spironolactone (e.g., gynecomastia, antiandrogen effects).
A 66-year-old woman is being treated in the ER for an acute MI. Nitroglycerin is given with the expectation that it will vasodilate which vessels preferentially? Another patient in the ICU is on hydralazine for acute treatment of his severe hypertension. How does hydralazine function? (FA15 p304-305) (FA16 p298-299)
venodilators (dec. preload)
hydralazine dilates arteries (dec. afterload)
What risk factors are associated with cholesterol gallstones? What risk factors are associated with pigment gallstones? (FA15 p375) (FA16 p372)
cholesterol stone risk factors: obesity, Crohn disease, advanced age, clofibrate, estrogen therapy, multiparity, rapid weight loss, Native American origin
pigment stones risk factors: seen in patients with chronic hemolysis, alcoholic cirrhosis, advanced age, biliary infections, total parenteral nutrition (TPN)
A 35-year-old woman with multiple sclerosis presents to clinic with internuclear ophthalmoplegia. What is internuclear ophthalmoplegia? (FA15 p486) (FA16 p490)
Lesion in MLF, a conjugate horizontal gaze palsy. Lack of communication such that when CN VI nucleus activates ipsilateral lateral rectus, contralateral CN III nucleus does not stimulate medial rectus to fire. Abducting eye gets nystagmus (CN VI overfires to stimulate CN III). Convergence normal
*MLF in MS*
A female infant is brought to the clinic for evaluation of her genitalia. On exam, clitoromegaly and labial fusion is noted. Lab studies reveal elevated 17-hydroxyprogesterone levels. What is the most common form of adrenal hyperplasia? Which hormone levels are altered as a result of this enzyme deficiency? What are the clinical manifestations of this enzyme deficiency? (FA15 p318) (FA16 p312)
increase 17-hydroxyprogesterone, increase androgens, decrease mineralcorticoids
21: dec. BP, inc. sex hormones
11 (B-hydroxylase): increase in BP and androgens ^^
17 (a-hydroxylase): increase in BP, decrease in sex hormones
What is the mechanism of action of the following antiemetics? (FA15 p251, 380) (FA16 p245, 376)
Scopolamine: musc. antag. @ CNS
Promethazine and Prochlorperazine: dopamine (D2) receptor antagonists that belongs to the phenothiazine class
Metoclopramide: D2 receptor antagonist. ^^resting tone, contractility, LES tone, motility. Does not influence colon transport time.
Ondansetron: 5-HT3 antagonist; dec. vagal stimulation. Powerful central-acting antiemetic
A 25-year-old man complains of a scrotal mass and pain made worse by coughing or sneezing. A scrotal exam reveals a palpable scrotal protrusion with the Valsalva maneuver. What type of hernia is this patient experiencing? What type of hernia protrudes through Hesselbach’s triangle? What structures form Hesselbach’s triangle? (FA15 p352) (FA16 p349)
Can't tell via exam
Direct: Protrudes through the inguinal (Hesselbach) triangle. Bulges directly through abdominal wall medial to inferior epigastric artery. Goes through the external (superficial) inguinal ring only. Covered by external spermatic fascia. Usually in older men.
Indirect: Goes through the internal (deep) inguinal ring, external (superficial) inguinal ring, and into the scrotum. Enters internal inguinal ring lateral to inferior epigastric artery. Occurs in infants owing to failure of processus vaginalis to close (can form hydrocele). Much more common in males. covered by all 3 layers of spermatic fascia
"MDs don’t LIe":
Medial to inferior epigastric artery = Direct hernia.
Lateral to inferior epigastric artery = Indirect hernia
Hesselbach triangle: Inferior epigastric vessels, Lateral border of rectus abdominis, Inguinal ligament
How does a decrease in renal artery pressure cause an increase in blood pressure? (FA15 p534) (FA16 p540)
increase in renin to compensate, increase Ang II-->vasoconstriction and increase aldosterone
What are the three endogenous androgens in order from the most potent to the least potent? (FA15 p577) (FA16 p582)
What is Osler-Weber-Rendu syndrome? (FA15 p83) (FA16 p71)
Hereditary hemorrhagic telangiectasia: Inherited disorder of blood vessels. Findings: branching skin lesions (telangiectasias), recurrent epistaxis, skin discolorations, arteriovenous malformations (AVMs), GI bleeding, hematuria
What is the fibrous band attached to the testis and scrotum that aids in normal testicular descent? What is this structure called in females? (FA15 p569) (FA16 p573)
Ovarian ligament + round ligament of uterus.
What are the effects of NSAIDs’ inhibition of PGE2? (FA15 p445) (FA16 p447)
What role do prostaglandins and angiotensin II play on the renal arterioles? (FA15 p530, 532) (FA16 p535, 537)
Block PGE2 synthesis
PGs vasodilate afferent arteriole,
AngII constricts efferent arteriole,
both increase GFR
What is the difference between a case-control study, a cohort study, and a clinical trial? (FA15 p48) (FA16 p32) (SU p17-18)
Which studies use odds ratios, and which use relative risks? (FA15 p48, 50) (FA16 p32, 34) (SU p18)
Case-control: retrospective; Compares a group of people with disease to a group without disease. Looks for prior exposure or risk factor. Asks, “What happened?” (odds ratio)
Cohort: Prospective or retrospective Compares a group with a given exposure or risk factor to a group without such exposure. Looks to see if exposure ^^ the likelihood of asks, “Who will/has develop(ed) disease?” (relative risk)
clinical trial: Compares therapeutic benefits of 2 or more treatments, or of treatment and placebo