uWorld 19 Flashcards

1
Q

what is train-of-four (TOF) stimulation

A

used during anesthesia to assess the degree of paralysis induced by NMJ-blocking agents
a peripheral nerve is stimulated 4 times in quick succession and the muscular response is recorded
the height of each bar represents the strength of each twitch; higher bars indicate the activation of increasing numbers of individual muscle fibers (myocytes)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

what is seen on TOF stimulation when a NON depolarizing NMJ blocker (vercuronium) is administered

A

competitive inhibition of postsynaptic acetylcholine receptors at the motor endplate prevents some of these fibers from activating, decreasing the strength of the twitch
PROGRESSIVE REDUCTION in each of the 4 responses (FADING PATTERN) as a result of less acetylcholine being released with each subsequent impulse (due to additional effect of presynaptic acetylcholine receptor blockade)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

what is seen on TOF stimulation when a depolarizing NMJ blocker (vercuronium) is administered

A

initially function by preventing depolarization of the motor endplate and show EQUAL REDUCTION of all 4 twitches during TOF stimulation (PHASE I BLOCKADE)
the responses remain equal b/c presynaptic acetylcholine receptor stimulation helps to mobilize presynaptic acetylcholine vesicles for release
persistent exposure to succinylcholine results in eventual transition to PHASE II BLOCKADE as the acetylcholine receptors become desensitized and inactivated (functionally similar to nondeplolarizing blockade)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

succinyl choline is commonly administered for what

A

RAPID-SEQUENCE INTUBATION due to its rapid onset (less than 1 minute)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

twisting injury or blow t the lateral knee while the foot is planted (VALGUS STRESS INJURY) to the knee results in what

A

MEDIAL COLLATERAL LIGAMENT (MCL) injury

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

what is the valgus stress test

A

performed when the knee is extended by placing one hand along the lateral thigh and pressing inward while the other hand is placed not eh medial aspect of the ankle and pushed outward
laxity of the knee and/or medial joint line widening indicate MCL injury

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

how is meniscal injury diagnosed

A

joint line tenderness while the knee is flexed

medial meniscal injury can occur with twisting moment of the knee and often accompanies MCL injury

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

what does the act do and what tests are there for its injury

A

resits anterior movement and the medial rotation of the tibia
injury indicated by increased anterior movement of the tibia in relation to the femur
anterior draw test
Lachman test

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

excessive backward movement of the tibia in relation to the femur indicates what

A

posterior draw test

PCL injury

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

what is ATTRITION BIAS

A

the loss of subjects differ in their rest of developing the outcome compared to the raining subjects
is a form of SELECTION BIAS

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

what is misclassification bias

A

occurs when exposure or the outcome is not identified correctly
random (or nondiffernetial) misclassification affects all the groups the same
Ex: pediatric cuff used on adults in a study but the control and the treatment used the same cuff = random missclassificaiton

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

NADH methemoglobin reductase does what and a deficiency results in what

A
reduces ferric (fe3+) iron to ferrous (Fe2+) iron, regenerating hemoglobin from methemoglobin
deficiency results in methemoglobinemia
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

goblin chain denaturation occurs in what disorder

A

G6PD deficiency

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

what cytokine causes cachexia

A

TUMOR NECROSIS FACTOR-ALPHA (aka cachectin) by suppressing appetite and increases basal metabolic rate
along with IL-1beta and IL-6 are main mediators of paraneopalsic cachexia

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

TNF-alpha is produced by what and mediates what

A
macrophages
fever (along with IL-1), mediates many of symptoms of septic shock, causes hepatic release of ACUTE PHASE REACTANTS (c-reactive protein, fibrinogen, hepcidin)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

what does IL-3 do

A

produced by activated CD4+ Th cells

stimulates growth and fifernetiaiton of myeloid cells

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

what is the main function of TGF-beta

A

inhibition of inflammatory response

decreases T-cell proliferation and cytokine prodcution

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

what is seen histologically in the kidneys from the damage that calcineurin inhibitors (cyclosporine, tacrolimus) do

A

early arteriolar hyalinization and TUBULAR VACUOLIZATION

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

what is seen in wischott aldrich

A

WATER
thrombocytopenia (petechia, purpura, hematemesis and epistaxis)
eczema
recurrent infections (combined B and T-lyphocyte disorder)

increased risk of PYOGENIC INFECTIONS b/c they can’t mount immune response to things with polysaccharide capsule (N. meningitis, H flu, step pneumo)
t-cell defect they get fucked by PCP and HSV

becomes apparent at 6 months
treated with HLA-matched bone marrow

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

what are the important clinical findings of Chediak higashi

A

ocular albinism
peripheral neuropathy
immunodeficiency related to dysfunction of phagolysosome formation

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

what is seen in Krebbe disease

A

galactocerebroside accumulation

progressive neurodegeneration, peripheral neuropathy, optic atrophy

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

what is seen in Fabry disease

A

globotriaosylceramide accumulation

causes angiokeratomas, peripheral neuropathy, and glomerulopathy that typically present in adulthood

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

what is seen in von Gierke disease

A
glucose-6-phosphatase deficiency
hepatomegaly
hypoglycemia
seizures
lactic acidosis
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

what is seen in pompe

A

lysosomal alpha-1,4-glucosidase deficiency
cardiomegaly
severe hypotonia

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

blood supply to the femoral head derives mainly from where

A

ascending cervical and retinaclular branches of the MEDIAL CIRCUMFLEX ARTERY (branch off deep femoral)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
26
Q

what arteries form the trochanteric anastomosis

A

branches of the lateral circumflex and superior and inferior gluteal arteries join with the medial circumflex artery

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
27
Q

what vessel is important in children because it supplies the region of the femoral head proximal to the epiphyseal growth plate

A

artery of ligamentum heres (form the obturator artery)

minimal clinical significance in adults

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
28
Q

abdominal and flank bruits are specific for what

A

renal artery stenosis

but found in minority of patients

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
29
Q

what is a root cause analysis

A

quality improvement measure that aims to identify what, how and why an undesirable outcome occurred
first step is collecting data to obtain complete information about the event or events

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
30
Q

RB tumor suppressor gene (anti-oncogene) is located where

A

Ch 13

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
31
Q

a blood flow curve showing cyclical variation in flow during the cardiac cycle, with MAXIMUM FLOW occurring during DIASTOLE and minimal flow occurring during ventricular systole is unique for what tissue

A

LEFT VENTRICULAR MYOCARDIUM
majority of blood flows through the vascular beds when the myocardium is relaxed and not comprising the vessels

systolic reduction in flow is greatest in subendocardial myocardium (where wall pressure is the highest)- region is prone to ischemia and MI

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
32
Q

the right ventricle blood flow appears how throughout the cardiac cycle

A

relatively constant
pressures in right ventricle are much lower than the left, and as a result the increase in systemic blood pressure during diastole is able to compensate for the rise in right ventricular wall pressure

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
33
Q

what are markers of osteoclast activity and what is the most reliable of the three

A
tartrate-resistant acid phosphatase
urinary hydroxyproline (also found in meat products)
urinary DEOXYPYRIDINOLINE (most reliable)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
34
Q

what is a reflects osteoblastic activity

A

bone-specific alkaline phosphatase

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
35
Q

what does pyridinoline do

A

covalently cross-links collagen fibers

these cross-links are the most commonly used method in assessing osteoclastic activity

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
36
Q

whats the difference between urticaria and angioedema

A

urticaria is due to increased permeability of the micro vasculature leading to edema of the SUPERFICIAL DEMRIS

angioedema is involvement of the deep semis and subcutaneous tissue

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
37
Q

what is dyskeratosis

A

abnormal, premature keratinization of individual keratinocytes
strongly eosinophilic and may have small, basophilic nuclear remnant
found in squamous cell carcinoma

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
38
Q

what is acantholyisis

A

loss of cohesion b/w keratinocytes in the epidermis

seen in pemphigus family of disorders

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
39
Q

what is acanthosis

A

diffuse increase in thickness of the status sinus (prickle cell layer) b/w the granular cell layer and the basal layer of the epidermis

psoriasis, seborrheic dermatitis, acanthosis nigricans

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
40
Q

what is spongiosis

A

intercellular epidermal edema that histologically appears as an increase in the width of places b/w cells
often associated with spongiotic dermatitis, which encompasses a number of conditions (eczematous dermatitis)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
41
Q

URTICARIA a common transient HYPERSENSITIVITY disorder is characterized by intensely pruritic, raised, erythematous plaques (WHEALS) that arise suddenly and resolve over several hours, what causes this

A

IgE-meidated degranulation of mast cells
can also be due to non-IgE-mediated degranulation (opiates, radiocontrast agents, physical urticaria) or mast cell independent mechanisms (aspirin, hereditary andgioeurotic edema)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
42
Q

what does somatostatin do

A

secreted from “delta” cells in the pancreatic islet
decreases secretion of secretin, cholecystokinin, glucagon, insulin, and gastrin
inhibits production of growth hormone from anterior pituitary

43
Q

what is a somatostatinoma

A

rare pancreatic islet cell tumor arising from delta cells
present with:
hyperglycemia
steatorrhea (dec secretin and GI motility)
galbladder stones (dec CCK)
hypochlorhydria (dec gastrin)

44
Q

what is a derivative of the 1st aortic arch

A

maxillary artery

45
Q

what is a derivative of the 2nd aortic arch

A

stapedial artery (typically regresses in humans)

46
Q

what is a derivative of the 4th aortic arch

A

part of true aortic arch and the subclavian arteries

47
Q

what is a derivative of the 6th aortic arch

A

pulmonary arteries and ductus arteriosus

48
Q

serum IgG4 antibodies to the M-type phospholipase A2 receptor (PLA2R), a transmembrane protein abundant on podocytes is indicative of what

A

idiopathic membranous nephropathy

49
Q

minimal change disease is possibly due to what

A

abnormal T cell production of glomerular permeability factor that affects the glomerular capillary wall, leading to fusion of the foot processes and marked proteinuria

50
Q

mixed cryoglobulinemia is seen in patients with what

A

hepatitis C
renal disease likely due to IgM deposition in the glomerulus that leads to basement membrane thickening and cellular proliferation

51
Q

what is the MOA of buspirone

A

partial agonist fo the 5HT1a receptor
no muscle relaxant or anticonvulsant properties
no risk of dependence
slow onset of action

52
Q

what is seen on water deprivation test in patients with partial nephrogenic diabetes insipidus

A

slow but steady rise in urine osmolality with increasing serum osmolality after water deprivation
no further increase in urine osmolality with DDAVP, and the urine osmolality remains low

53
Q

what is seen in patients with primary polydipsia

A

increase in serum and urine osmolality on water deprivation that is similar to partial nephrogenic DI, however the correction in primary polydipsia is more rapid, and the urine osmolality returns t a level closer to normal (but still sub maximal due to washout of the medullar osmotic gradient)

history of psychiatric disorders or medication-induces xerostomia is usually present

54
Q

when and why does one see EUVOLEMIC HYPONATREMIA

A

SIADH
mild increase in extracellular fluid volume surpasses the renin-aldosterone axis and stimulates the production of the natriuretic peptides, leading to excretion of sodium in the urine (natriuresis)- normal body fluid volume and low plasma osmolality

55
Q

anti-A IgG and anti-B IgG is seen with what blood group(s)

A

O blood group (OO)

no antigen on RBC

56
Q

anti-A IgM is seen with what blood group(s)

anti-B IgM is seen with what blood group(s)

A

anti-A IgM: blood group B (B antigen on RBC)

anti-B IgM: blood group A (A antigen on RBC)

57
Q

what blood group has no antibodies in the serum

A

AB

but has A and B antigen on red blood cells

58
Q

what blood type mother can cause ABO hemolysis in a fetus

A

O because they have IgG anti-A and anti-B antibodies in serum which can cross the placenta causing hemolysis in the fetus

can occur in first pregnancy unlike Rh disease which requires a previous pregnancy

59
Q

what is Eptifibatide

A

inhibits platelet aggregation and thrombosis by blocking the glycoprotein IIb/IIIa receptor (binding site for fibrinogen)
typically used in acute coronary syndrome and in patients undergoing percutaneous coronary intervention

60
Q

what is ticagrelor

A

binds DP P2Y12 receptor on platelets, which prevent platelet aggregation by blocking ADP-mediated activation of GP IIb/IIIa receptor complex

61
Q

what are echinocandin antifungals

A

caspofungin- block gluten synthesis

62
Q

how does flu cytosine work

A

inhibits the synthesis of DNA (replication) and RNA (protein synthesis) in fungal cells

63
Q

how does griseofulvin work

A

enters fungal cells and binds microtubules, inhibiting mitosis
CPY450 inducer

64
Q

how does gabapentin work

A

blocking voltage-gated (presynaptic) calcium channels, thereby attenuating excitatory neurotransmitter release

65
Q

basement membrane splitting is seen on light microscopy using silver or PAS stains in what kidney problem

A

membrnaoproliferative glomerulonephritis (MPGN)
glomeruli have lobular appearance with proliferate mesangial cells and increased mesangial matrix
GRANULAR DEPOSITS seen on immunoflourescnece

66
Q

uniform, diffuse capillary wall thickening on LM is a sign of what kidney problem

A

membranous glomerulopathy
granular deposits of IgG and C3 on immunofluorescence
typical nephrotic syndrome presentation

67
Q

what is seen on immunofluorescence of focal segmental glomerulosclerosis (FSGN)

A

IgM and C3 deposits may be seen in the sclerotic areas due to nonspecific trapping of these components

68
Q

what are the deposits made of in good pastures

A
IgG and C3 linear deposits
from anti-GBM antibodies targeting type IV collagen
glomerular crescents (RPGN) on LM (proliferating parietal cells with an infiltration of monocytes and macrophages are seen on LM
69
Q

viral RNase H does what

A

removes the RNA primary, allowing for completion of newly synthesized DNA
important pharmaceutical targets for the treatment of retroviruses such as HIV

70
Q

what is seen on the CSF of herpes simplex encephalitis

A

HEMORRHAGIC LYMPHOCYTIC PLEOCYTOSIS with INCREASED protein and normal glucose
also abnormal MRI signal in the bilateral TEMPORAL LOBES

TX: IV acyclovir

71
Q

what kind of receptor is Human epidermal growth factor receptor 2 (HER2)

A

TYROSINE KINASE

blockade of HER2 w/ trastuzumab downregulates CELLULAR PROLIFERATION and PROMOTES APOPTOSIS

72
Q

what is bevacizumab

A

monoclonal antibody to vascular endothelial growth factor (VEGF) which binds a TYROSINE KINASE

treats METASTATIC cancers (colon, lung)

73
Q

what is denosumab

A

human monoclonal antibody against RANKL

used to reduce skeletal-related events if bets to bone occurs

74
Q

when are aromatase inhibitors (anastrozole, letrozole) used for

A

adjunct therapy for postmenopausal patients who have breast cancer with ER and/or PR tumor expression

75
Q

changes in the concentration and ratios of components such as ______ can shift the balance of urine to cause salt precipitation and stone formation

A
calcium
phosphate
oxalate
uric acid
citrate

increased concentrations of all (BUT CITRATE) promote formation of stones

76
Q

high urine concentrations of what has stone-preventing effect by binding free (ionized) calcium, preventing its precipitation and facilitating its excretion

A

CITRATE

potassium citrate is often prescribed to prevent recurrent calcium stones in adults when dietary modifications are unsuccessful

77
Q

what is required for the formation of uric acid and cysteine stones, and also promotes calcium oxalate crystal formation

A

acidic pH

78
Q

hyperuricosuria is associated with what conditions

A

gout
myeloproliferative disorders
situations of high purine and alcohol intake
can be idiopathic

79
Q

what is a pancreatic pseudocyst

A

common compilation of pancreatitis
collection of fluid rich in enzymes and inflammatory debris
inflammatory reaction in the walls of the surrounding organs

80
Q

what makes up a pancreatic pseudocyst

A

walls consist of granulation tissue and NO epithelial lining

fibrosis, thickening and organization of the walls occur with tie

formation of firm fibrotic pseudocyst walls (“maturation” of pseudocyst) takes about 4 to 6 weeks following the episode of acute pancreatitis

81
Q

what is the most common location for a pseudocyst

A

the lesser peritoneal sac, bordered by the stomach, duodenum and transverse colon
walls are closely adherent to the surrounding hollow organs

82
Q

when are glycogen-rich cuboidal epithelium seen in the pancreas

A

serous pancreatic neoplasms

83
Q

when is columnar mucinous epithelium found in the pancrease

A

mucinous cystic neoplasms of the pancreas

84
Q

when are atypical cells forming papillary projections seen in the pancreas

A

papillary variant of pancreatic adenocarcinoma

85
Q

the blood supply tot he PROXIMAL URETER comes from where

what about the distal ureter

A

proximal ureter: the RENAL ARTERY

distal ureter: superior vesical artery

in between: anastomotic and highly variable, with possible afferent branches form the gonadal, common iliac, aorta, and uterine arteries

86
Q

how is the blood supply established in a kidney transplant

A

anastomosing the DONOR RENAL ARTERY with the RECIPIENT EXTERNAL ILIAC ARTERY

proximal 1/3 of donor ureter is preserved and used to establish continuity from the collecting system of the kidney to the recipients bladder

distal part is susceptible to ischemia due to lack of anastomotic connections

87
Q

what is a recognized complication of renal transplant and causes leakage of urine 5-10 days following transplant

A

distal ureteral ischemia

88
Q

what is an aspergilloma (mycetoma)

A

aspergillus COLONIZATION of a PREEXISTING LUNG CAVITY forming a FUNGUS BALL

may be asymptomatic or may cause cough and HEMOPTYSIS

not contagious

89
Q

when does one see invasive aspergillosis

A

invasive pulmonary aspergillosis occurs in severely immunosuppressed and neutropenic patients and is characterized by primary lung involvement with cough, hemoptysis, pleuritic chest pain, fever

necrotizing pneumonia and granuloma formation also occur

extra pulmonary involvement is common

90
Q

what is a EUNUCHOID BODY HABITUS and when is it seen

A

result of testosterone deficiency
tall stature and gynecomastia
facial and body hair is sparse or absent and muscle mass is decreased

seen in KLINEFELTER

91
Q

when does one see short stature, hypotonia, intellectual disability and obesity

A

prader-willi

microdeletion of paternal ch 15p11-13

92
Q

when does one see macroorchidism, large jaw, and intellectual disability

A

FRAGILE X SYNDROME

X-linked disorder w/ mutations in FMR1 gene

93
Q

arachnodactylyl, scoliosis, and aortic rood dilation are signs of what

A

Marfan

fibrillar defect

94
Q

when are necrotizing inflammation and pulmonary hemorrhage seen

A

granulomatosis with polyangitis

presents sub acutely with cough, dyspnea, and hemoptysis and neuritic syndrome

95
Q

fevers, hemodynamic instability, tachypnea, and evidence of urinary tract infection with urosepsis is likely complicated by what

A

ACUTE RESPIRATORY DISTRESS SYNDROME (ARDS)

sepsis and pulmonary infections are the two most common risk factors for ARDS

96
Q

what is AR ORGANIC ACIDEMIA

A

deficiency of enzyme METHYLMALONYL-CoA MUTASE

result is a build up of methylmalonic acid and propionic acid leading to METABOLIC ACIDOSIS

HYPOGLYCEMIA results from overall increased metabolic rate leading to increased glucose utilization and direct toxic inhibition of gluconeogenesis by the organic acids

KETONES are produced in preens of hypoglycemia

HYPERAMMONEMIA occurs from organic acids directly inhibiting the urea cycle

97
Q

what are the signs of organic acidemia (methylmalonaly-CoA mutase deficiency)

A

anion gap metabolic acidosis
hypoglycemia
ketosis
hyperammonemia

evaluated during METHYLMALONIC ACID AND PROPIONIC ACID

98
Q

wha is propionic acidemia

A

deficiency in propionyl-CoA carboxylase

hyperammonemia
hypoglycemia
metabolic acidosis

NO elevated METHYMALONIC ACID

99
Q

production of ketones in the presence of hypoglycemia is the normal response of what

A

fasting state (as keynotes provide fuel for brain)

100
Q

fatty acid oxidation disorder, like medium-chain acyl-CoA dehydrogenase (MCAD) deficiency, can present with what

A

hypoglycemia
hyperammonemia
metabolic acidosis

101
Q

urea cycle defects typically present with what

A

hyperammonemia without hypoglycemia or ketosis

102
Q

nutritional deficiencies can result in what kind of myopathy

A

dilated

Thiamine (B1) (wet beriberi heart disease) or chronic anemia

103
Q

what is seen histologically in viral myocarditis

A

lymphocytic interstitial inflammatory infiltrate, w/ focal across of myocytes adjacent to areas of inflammatory cells

104
Q

toxic agents like alcohol, cocaine, iron (in hemochromatosis), or doxorubicin may cause what heart problem

A

dilated cardiomyopathy