uWorld 32 Flashcards

1
Q

what is seen in a newborn with midgut malrotation

A

cecum wil rest in the right upper quadrant instead of the right lower quadrant

LADD’S (FIBROUS) BANDS connect the retroperitoneum to in the RLQ to the right colon/cecum by PASSING OVER the SECOND PART of the DUODENUM, causing INTESTINAL OBSTRUCTION in the process

obstruction presents as BILIOUS VOMITING during the FIRST DAYS of life

mesentery is vulnerable to tWISTING around the SUPERIOR MESENTERIC ARTERY- midgut VOLVULUS which comprises intestinal profusion and may lead to life-threatening bowel necrosis

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2
Q

what is seen if a lower cutoff point is used (in terms of sensitivity and stuff)

A

increase in number of overall positive results

sensitivity of the test increases

true positive values increase but false positive increase more

positive predictive value decreases

false negatives decrease

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3
Q

anovulation is a common cause of infertility how can this be treated

A

menotropin (human menopausal gonadotropin) is a treatment option that acts like FSH and trigger the formation of a dominant ovarian follicle

ovulation is then induced by administration of human chorionic gonadotropin which mimics the LH surge

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4
Q

when during menstruation are peak progesterone levels

A

mid luteal phase

after ovulation when the corpus luteum is formed

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5
Q

nitric oxide is formed from what

A

ARGININE, NADPH, and O2 by eNOS (endothelial nitric oxide synthase)

NO activates guanylyl cyclase → cGMP → less cytosolic coliseum and RELAXATION of vascular smooth muscle cells

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6
Q

arginine is used to make what

A

nitric oxide
urea (w/ help of aspartate)
creatine (w/ help of glycine and SAM)

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7
Q

aspartate is used to make what

A

urea (w/ help of arginine)
pyrimidines (w/ help fo glutamine
purines (w/ help of glycine and glutmaine)

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8
Q

glycine is used to make waht

A

heme (w/ help of succinyl CoA)
creatine (w. help of arginine and SAM)
purines (w/ help of glutamine and aspartate)

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9
Q

glutamine is used to make what

A

pyridines and purines

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10
Q

what is glutamate used to make

A

GABA

glutathione

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11
Q

what all is derived form tyrosine (which comes from phenylalanine itself)

A
dopamine
epinephrine
norepinephrine
thyroxine
melanin
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12
Q

what is asymmetrical dimethyarignine

A

an endogenous analog of arginine that work as a competitive inhibitor of eNOS

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13
Q

what is nor present in all tRNAs

A

variable loop (lies between the T and anticodon loops)

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14
Q

what is the T loop of tRnA

A

has the T(psi)C sequence- necessary for BINDING of tRNA to RIBOSOMES

(ribothymidine and pseudouridine, and cytidine presence tells you this is around)

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15
Q

what are ApoE3 and ApoE4 responsible for

A

found own CHYLOMICRONS and VLDL

binding hepatic apolipoprotein receptors for their removal

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16
Q

what is ApoA1 required for

A

esterification of free cholesterol in HDL particles by lecithin-cholesterol acyltransferase (LCAT)

ApoA1 and LCAT deficiencies result in low HDL levels and increased circulating free cholesterol levels

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17
Q

what is familial chylomicronemia syndrome and what causes it

A

AR disorder of defective LIPOPROTEIN LIPASE or ApoC3 (which activates LPL)

increased synthesis and decreased clearance of chylomicron particles (and VLDL)

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18
Q

why is DNA polymerase I unique

A

only prokaryotic polymerase that also has 5’ to 3’ EXONUCLEASE ACTIVITY

functions to REMOVE the RNA PRIMER reacted by RNA primase and REPAIR DAMAGED DNA sequences

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19
Q

what is the major early biochemical consequence of total myocardial ischemia and when does it happen

A

cessation of aerobic glycolysis and initiation of anaerobic glycolysis

transition occurs within seconds

although TOTAL ATP levels remain normal during first few minutes of ischemia, ATP is rapidly depleted form areas of cell with high demand

the DEPLETION of ATP in CRITICAL CELLULAR areas and the ACCUMULATION of TOXINS results in LOSS of CONTRACTILITY within about 60 seconds of total myocardial ischemia

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20
Q

when does ischemia become irreversible

A

after about 30 minutes of TOTAL ISCHEMIA

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21
Q

what are benign lung tumors

A

HAMARTOMAS
“coin lesions” found incidentally on chest x-ray

mature hyaline cartilage mixed with connective tissue, smooth muscle, and fat

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22
Q

what is seen in adenocarcinoma in site (aka bronchioloalveolar carcinoma)

A

consists of WELL-DIFFERENTIATED, dysplastic COLUMNAR CELLS (with or without MUCIN) that line the INTACT alveolar septa without vascular or stromal invasion

tendency to undergo erogenous spread and can progress to invasive disease if not resected

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23
Q

what causes edwards syndrome (trisomy 18)

A

MEIOTIC NONDISJUCNTION

error in oocyte division occurs prior to ovulation and fertilization and increases with maternal age over 35

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24
Q

what is seen in cri-du-chat syndrome

A

microdeleiton of 5p

cat-like cry as well as hypotonia, failure to thrive, developmental delay

microcephaly
low-set ears
hypertelorism
broad nasal bridge

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25
Q

anti-Rh immune globulin consists of what

A

IgG anti-D antibodies that opsonize Rh+ fetal erythrocytes, promoting clearance by material reticuloendothelial macrophages and preventing maternal Rh sensitization

giben at 28 weeks gestation and immediate postpartum period

26
Q

what is ANASTROZOLE (and letrozol, exemestane)

A

ATOMATASE INHIBITOR

reduce synthesis of estrogen from androgens, surpassing estrogen levels in post menopausal women and SLOWING PROGRESSION of ER-POSITIVE TUMORS

less effective in premenopausal women become ovarian aromatase is unregulated substantially in response to gonadotropins

27
Q

what diuretics work as the thick descending loop of henle

A

osmotic (also work at proximal convoluted tubule)

28
Q

what is seen in Jugular Foramen (Vernet) Syndrome

A

CN IX, X, XI dysfunction

loss of ease from posterior 1/3 of tongue (CN IX)
loss of gag reflex (CN IX, X)
dysphagia (CN IX, X)
dysphonia/hoarseness (CN X)
soft palate drop with deviation of the uvula toward the normal side (CN X)
sternocleidomastoid and trapeius muscle paresis (CN XI)

29
Q

what causes the shift of pain in appendicitis to shift from the umbilicus to McBurneys point (2/3 form umbilicus to ASIS)

A

the appendix becomes more inflamed and ti irritates the PARIETAL PERITONEUM and abdominal wall and causes a MORE SEVERE SOMATIC PAIN

30
Q

an inflamed appendix lying against what would cause RLQ pain with INTERNAL ROTATION of the RIGHT HIP

A

RIGHT OBTURATOR INTERNUS

31
Q

an inflamed appendix lying against what would cause RLQ pain with HIP EXTENSION

A

PSOAS

32
Q

how does botulism usually present

A

3D’s:
DIPLOPIA, DYSPHAGIA, DYSPHONIA usually 12-36 hours after consumption

descending paralysis

HEAT-LABILE disease that can be prevented by thoroughly heating food prior to consumption

33
Q

what does hemicholinium do

A

blocks choline uptake by the presynaptic neuron

prevents ACh synthesis through depletion of intracellular choline

34
Q

what does bromoacetylcholine do

A

inhibits acetyltransferase

blocking the synthesis of ACh from acetate and choline

35
Q

what id VESAMICOL

A

non competitively blocks the vesicular ACH transporter, preventing ACh from ENTERING SECRETORY VESICLE

36
Q

patient with microcytic anemia and low ferritin (suggesting iron deficiency anemia) and history of heavy menstrual periods and nosebleeds as a kid
whats she got

A

von Willebrand factor deficiency (bleeding from skin and mucosal sites)

iron deficiency from occult blood loss due to above

37
Q

what is the role of vWF

A

promoter fo platelet adhesion at sites of vascular injury by binding platelet glycoproteins (Gp1b) to sub endothelial collagen on injured blood vessel walls

protective carrier for factor VIII

38
Q

what is PARANEOPLASTIC CEREBELLAR DEGENERATION (subacute cerebellar degeneration)

A

paraneoplastic syndrome associated with SMALL CELL LUNG, breast, ovarian, and uterine malignancies

progressively worsening DIZZINESS, LIMB, and TRUNCAL ATAXIA, DYSARTHRIA, and VISUAL DISTURBANCES (diplopia, oscillopsia)

immune reaction against tumor cells that CROSS-REACTS with PURKINJE neuron ANTIGENS, leading to acute-onset rapid degeneration of the cerebellum

39
Q

Anti-Yo, anti P/Q and anti-Hu antibodies are seen in what paraneoplastic syndrome

A

PARANEOPLASTIC CEREBELLAR DEGENERATION (subacute cerebellar degeneration)

(seen in SMALL CELL LUNG, breast, ovarian, and uterine malignancies)

40
Q

Wegeners (granulomatosis with polyangitis) does what in the kidney

A

rapidly progressive (crescent) glomerulonephritis (RPGN) type 3 (pouci immune)

41
Q

serrates anterior is innervated by what, what is its action

A

LONG THORACIC nerve (C5-C7_

stabilize and ROTATE the SCAPULA UPWARD

42
Q

paralysis of serratus anterior (knife wound to side of chest, radical mastectomy) does what

A

winged scapula

weakness abducting the arm able horizontal due to impaired rotation of the scapula

43
Q

what are the side effects of amphotericin B

A
renal toxicity:
severe hypokalemia and hypomagnesemia (likely reflecting increased distal tubular membrane permeability)
can decrease EPO production 
vasoconstriction and ↓ GFR
acute tubular necrosis
renal tubular acidosis
44
Q

what is a side effect of daptomycin

A

rhabdomyolysis (increased creatine phosphokinase)

45
Q

TSH monitoring is recommend for people on what drugs

A

amiodorone

lithium

46
Q

what do aprepitant and posaprepitant do

A

neurokinin 1 (NK1) receptor antagonists

inhibit substance P and help prevent both acute vomiting and delayed emesis

47
Q

what do Golgi Tendon Organs do

A

sensory receptors located at the junction of the muscle and tendon that are innervated by GROUP IB sensory axons

connected in series with contrasting extrafusal skeletal muscle fibers

when a muscle actively contracts against resistance, the increase in tension is transmitted through the tendon activating the GTOs in the process

not sensitive to muscle length change (happens primarily at the fibers not the tendon)

48
Q

muscle spindles (intrafusal muscle fibers) are innervated by what

A

innervated by GROUP IA and GROUP II sensory axons and are sensitive to changes in muscle length

mediate the STRETCH REFLEX (MYOTATIC reflex) which is commonly tested (deep tendon reflexes) during the neurologic examination

when the muscle is stretched there is a monosynaptic reflex activation of the alpha motor neuron (of the same muscle), causing contraction that resists the stretch

connected in parallel with extrafuscal fibers

49
Q

what do pacinian corpuscles do

A

RAPIDLY adapting mechanoreceptors
subcutaneous tissue of the skin as well as the mesentery, peritoneum, and joint capsules

mediate touch, proprioception and vibratory sensation

inverted by MYELINATED A-beta fibers

50
Q

what are Ruffini’s end organs

A

SLOWLY adapting mechanoreceptor that exist in the skin, subcutaneous tissue and joint capsule

mediate touch, proprioception and vibratory sensation

inverted by MYELINATED A-beta fibers

51
Q

what are A-delta fibers

A

thin, myelinated nerve fibers whose FREE NERVE ENDINGS detect TEMP and NOCICEPTIVE stimuli

acute (sharp) pain and constitute afferent portion of the REFELX ARC that mediates WITHDRAWAL from NOXIOUS STIMULI

52
Q

colitis-associated carcinoma is more likely to have what features (compared to sporadic colorectal carcinoma)

A
  1. affect YOUNGER patines
  2. progress from FLAT and NON-POLYPOID DYSPLASIA
  3. histologically appear MUCINOUS and/or have SIGNET RING morphology
  4. develop EARLY p53 mutations and LATE APC gene mutations, opposite that of sporadic disease
  5. be distributed within the PROXIMAL COLON (esp in Crohns or primary sclerosing cholangitis)
  6. be MULTIFOCAL in nature
53
Q

collitis-asociated carcinomas are more likely to arise from non-polypoid dysplastic lesions, be multifocal in nature, develop early p53 mutations and late APC gene mutations, and be of a higher histological grade

A

know that

54
Q

what is the most effective strategy at preventing neonatal tetanus

A

vaccination of pregnant woman (and those of childbearing age)- this provides TRANSPLACENTAL IgG to the fetus

hygienic delivery and cord care

55
Q

clump of soli on umbilical cord

A

TETANUS

56
Q

how its tetanus treated

A

antibiotics to kill C tetani and administration of tetanus immune globulin to neutralize unbound toxin

57
Q

what is pure red cell aplasia (PRCA)

A

rare form of marrow failure characterized by severe hypoplasia of marrow ERYTHROID elements in the setting of normal granulopoiesis and thrombopoisesis

58
Q

what causes pure red cell aplasia (PRCA)

A

inhibition of erythropoietic precursors and progenitors by IgG autoantibodies or cytotoxic T lymphocytes

associated with immune system diastase such as THYMOMAS and LYMPHOCYTIC LEUKEMIAS

PARVOVIRUS B19 (can detect anti-B19 IgM antibodies)- virus preferentially attacks and destroys proerythroblasts

59
Q

what does IkappaB do

A

bind NF-kappaB and keeps it in a latent, inactive state

activation of IkappaB KINASE results in UBIQUITINATION and subsequent destruction of IkappaB with the release of free NK-kappaB

once free, NK-kappaB enters the nucleus and promotes the synthesis of a number of INFlAMMATORY PROTEINS such as cytokines, acute phase reactants, cell adhesion molecules, and leukocyte related growth factors

60
Q

what is TNF-alphas role in response to infection

A

increase neutrophil chemotaxis and stimulating macrophage phagocytosis

unregulated by NF-kappaB

61
Q

how does HBV increase risk for hepatocellular carcinoma

A

integrates into host DNA
(this allows for transcription of viral oncogenic proteins like HBc PROTEIN which disrupts cell-cycle control by activating multiple gtowth-proming genes an inactivating p53 TUMOR SUPPRESSOR PROTEIN)