#5 3/9 Flashcards Preview

UWorld mixed > #5 3/9 > Flashcards

Flashcards in #5 3/9 Deck (111):
1

Histology of (1) zona glomerulosa (2) zona fasiculata (3) zona retiularis (4) adrenal medulla

(1) rounded/arched cluster (2) foamy-appearing cells in columns (3) basophilic cells in anastomosing cords (4) basophilic cytoplam

2

Adrenal medulla releases...

80% Epi, 20% Norepi

3

Aldosterone secretion from zona glomerulosa regulated by... (2 things)

(1) Angiotensin II (2) extracellular K+ levels

4

TNF-alpha inhibitors treat...

Rheumatoid arthritis (STUDY MORE)
etanercept, inflixamab & adalimumab

5

First-line drug for established rheumatoid arthritis

methotrexate

6

NSAID side effects (3)

GI ulcer and bleeding, fluid retention (block prostaglandin-mediated vasodilation of afferent arteriole)

7

Kallmann's syndrome

Failure of GnRH-secreting neurons to migrate from olfactory lobes to hypothalamus (migration problem)

8

Thyroid development

(1) lower end of pharynx (2) migration along thyroglossal duct, from foramen cecum on dorsal surface of tongue to superior border of thyroid isthmus (can become sublingual if impaired

9

Parafollicular C-cells originate from

ultimobranchial bodies

10

Clinical presentation of hypothyroidism in children

lethargy, feeding problems, constipation, macroglossia, umbilical hernia, large fontanels, dry skin, hypothermia, prolonged jaundice

11

How does an enzyme speed up the reaction rate?

reduce the energy of the transition state (activation energy); cannot alter Gibbs free energy

12

deltaG describes..

direction of a chemical rxn & concentrations of reactants and products at equilibrium

13

deltaG0 describes..

change in free energy that accompanies formation of 1 mol of products from substrate under standard condition
exothermic = -deltaGo (spontaneous)
endothermic = +deltaGo

14

Differentiate mucor/rhizopus from aspergillus on microscopy & affected population

irregular BROAD non-septate hyphae branching at WIDE angles (vs. septate hyphae that branch at 45 degrees).

Aspergillus: chronic granulomatous disease & immunocompromised
Mucor/Rhizopus: diabetic ketoacidotic & leukemic

Both can cause sinusitis in immunosuppressed

15

Dimorphic Fungi

Body Heat Changes Shape: blastomycoses, histoplasma, coccidiomycoses, sporothrix

16

Thyrotoxicosis on serum calcium

hypercalcemia due to increased bone resorption

17

Familial hypocalciuric hypercalcemia (inheritance and defect)

autosomal dominant, defective calcium-sensing receptor on parathyroid cells & kidney

18

Hydrochlorothiazide electrolyte abnormalities:

elevated: glucose, lipid, uric acid, calcium
decreased: potassium, magnesium, sodium

19

Hypothyroid effect on skeletal muscle

myopathy: pale muscle fibers, decreased striation, deposition of mucinous material. atrophy or type II muscle fibers (increase in creatine kinase)

20

Elevated creatinine kinase isoform localize: CK-MB, CK-BB, CK-MM

CK-MB: cardiac muscle
CK-BB: nervous system
CK-MM: skeletal muscle

21

Common causes of elevated creatine kinase (4)

hypothyroidism, HMG-CoA reductase (statins), autoimmune disease (polymyositis, dermatomyositis), muscular dystrophy (Duchenne)

22

evolution of EPS side effects & Rx

4 hr: acute dystonia (muscle spasm, stiff, oculogyric crisis) rx: diphenhydramine
4 day: akathisia rx: propanolol
4 wk: bradykinesia rx: benztropine
4 mo: tardive dyskinesia rx: discontinue

23

localize thyroid hormone receptor

inside nucleus (also, retinoids, peroxisomal proliferating activated receptors, and fatty acids)

24

resistance to rifampin

genetic mutation in DNA-dependent RNA polymerase (RAPID when monotherapy)

25

use of rifampin (3)

(1) prophylactic monotherapy for H. flu and N. meningitidis; combo: (2) mycobacterium TB (3) leprosy

26

Rx: MAC

macrolide (clarithromycin or azithromycin)
rifampin
ethambutol

27

Rx: penicillin-resistant pneumococcus

ceftriaxone & vancomycin combination

28

Rx: staphylococcal endocarditis

IV penicillin & rifampin or aminoglycoside (synergistic)

29

Use of colchine & mechanism of action

rx: for acute gout & prophylaxis
binds & stabilizes tubulin, inhibiting leukocyte chemotaxis and degranulation
also reduces LTB4

30

-1st line Rx: acute gout
-preferred Rx in elderly/renal failure

-NSAID (anti-inflammatory, analgesic, anti-pyretic)
-intra-articular glucocorticoids

31

Side effect of colchine

GI

32

Use of leukotriene modulators (zileuton, montelukast, zafirlukast)

preventing recurrent of asthma & allergic rhinitis

33

ADH signal transduction

V2 receptor on principal cells in collecting duct -> increased cAMP -> fusion of endosomes with aquaporin 2 to luminal side -> increased water reabsorption

34

-highest & lowest tubular fluid osmolarity location (in presence of ADH? in absence?)
-osmolarity in PCT

highest: bottom of loop of henle (1200mOsm when ADH is high)
lowest: DCT (100mOsm)
PCT equivalent to serum (300mOsm)

in absence of ADH, most dilute in collecting ducts (as low as 50mOsm)

35

Cause of focal brain lesions in HIV+patients
(& other causes in any pt)

toxoplasma, CNS lymphoma (B cell; related to latent EBV infxn)
& primary brain tumor (globlastoma multiforme), metastatic carcinoma, abcesses (cryptococcus, TB)

36

Irreversible neuronal damage (neuronal shrinkage, eosinophilic cytoplasm) leads to

glial hyperplasia; reactive gliosis (NOT fibroblast)

37

Vertebral level: bifurcation of abdominal aorta
& common iliac vein merge to IVC

L4

38

vertebral level: renal vein entering IVC

L1-2

39

interomediolateral nucleus (lateral horn) levels

T1-L2

40

appetite suppressants (fenfluramine, phentermine, dexfenfluramine) for >3 months causes..

pulmonary HTN -> cor pulmonale -> sudden death from arrhythmia

41

cerebral berry aneurysm associated with which genetic disorders?

ADPKD and Eherlos-Danlos

42

medial calcinosis (affected vessels and prognosis)

calcific deposits in muscular artery >50y/o. affects femoral, tibial, radial, ulnar. and arteries to genital tract. do not narrow lumen, so asymptomatic

43

prominent finding in neonate/fetus with Turner (45X,O) along with others (think: lymph, cardiac, kidney)

- lymphedema of hands and feet
- abnormal nuchal lymphogenesis (subcutanoue nuchal edema and cystic hydroma)
- webbed neck/low posterior hairline
- cardiac abnormalities: coarctation of aorta, bicuspid aortic valve
- horseshoe kidney

44

adult presentation of Turner syndrome

(45 X,O) short stature, broad shield-like chest, webbed neck, primary ovarian failure -- streaked)

45

fetus with Down Syndrome

trisomy 21; flat face, abnormal ears, slanted palpebral fissures, redundant skin at nape of neck, hypotonia, pelvic dysplasia, single transverse palmar crease

46

Edwards syndrome

trisomy 18; edwards: prominent occiput, micrognathia, small mouth, low-set and malformed ears, rocker-bottom feet. CHARACTERESTIC: clenched hands with index overriding the middle finger, 5th overriding 4th

47

1st most common autosomal trisomy in liveborn infants? 2nd? 3rd?

trisomy 21, downs
trisomy 18, edwards
trisomy 13, patau (most severe)

48

Patau syndrome

trisomy 13; patau: holoprosencephaly, microcephaly, polydatyl, rocker-bottom feet. mult facial abnormalities (hypotelorism, micropthalmia, cleft lip, cleft palate, absent or malformed nose)

49

47 XXX

clinically silent, decreased IQ, no increase risk of stillbirth

50

Klinefelter syndrome

47 XXY; mild mental retardation or normal intelligence. tall male with gynecomastia, small testes, and infertility. no increase risk of stillbirth

51

glucose-6-phosphate dehydrogenase catalyzes what rxn?

glucose-6-phosphate --> 6-phosphogluconate (with NADP+ --> NADPH. rate limiting step in HMP shunt

52

glucose through hexose monophosphate (HMP) shunt creates...

(1) oxidative: NADPH as a reducing equivalent
- requires glucose-6-phosphate
(2) reductive: ribose 5-phosphate for nucleotide synthesis & intermediates for glycolysis
- requires transketolase (thiamine-dependent)

53

How do RBCs protect against oxidative injury?

HMP shunt, generates NADPH to maintain glutathione in a reduced state (via gluathione reductase)

54

G6PD histology & precipitants

X-linked; Heinz bodies (denatured hemoglobin from oxidative damage), destroyed in spleen
PAINS: primaquine, aspirin, isoniazid nifuratoin, sulfonamides

55

Ascorbic acid

vitamin C; hydroxylation of proline and lysine residues in collagen: CT maintenance and wound-healing

56

Clinical presentation of orotic aciduria and Rx

impaired de novo pyrimadine synthesis: hypochromic megaloblastic anemia, neurologic abnormalities, growth retardation, excretion of orotic acid in urine; uridine supplementation, inhibit carbamoyl phosphate synthetase II

57

Resting potential of skeletal myocytes? cardiac myocytes?

-75mV for skeletal
-90mV for cardiac (reduced risk of arrhythmia)

58

Plataeu phase of cardiac myocyte action potential

phase 2: opening of L-type DHP-sensitive Ca++ channels and closure of some K+ channels

59

Orchiectomy vs. Orchipexy

removal of abdominal testes vs. surgery that allows descent

60

Effect of having one testicle on (1) androgen levels (2) inhibin B levels

(1) androgen not effected (compensation)
(2) inhibin decrease (FSH increase)

61

High levels of cortisol on GnRH secretion

hypogonadotropic hypogonadism (suppressed GnRH hormone)

62

Lipofuscin pigment

'wear and tear' pigment; finely granular yellow brown pigment granules composed of lipid containing residues of lysosomal degradation (part of normal aging: heart, liver, kidney...)

63

Pathologic ventricular hypertrophy is characterized by... (2)

(1) morphologic changes (increased sarcomere content & volume of myocyte) and (2) gene transcription changes, i.e: ANP

64

ANP vs. BNP (who secretes it, in response to what)

ANP: secreted by atria & sometimes hypertrophic
BNP: predominately ventricles
both in response to volume overload --> natriuesis & diuresis

65

Laplace's law

distending pressure (pressure required to keep a sphere open) proportional to surface tension and inversely proportional to radius

P= 2T/r

as the radius of a sphere with constant ST decreases, pressure increases

66

Surfactant (2 effects)

prevent smaller airways from collapsing during expiration & regulates alveolar expansion (all at similar rates)

67

Chlamydia trachomatis cell wall

Lacks peptidoglycan in cell wall (muramic acid) and has cysteine residues instead (does have a cell wall, but can't be treated with penicillin/cephalosporins)

68

(2) organisms that lack a cell wall

Ureaplasma urealyticum & mycoplasma (increased cholesterol)

69

causes of urethritis

gonococcal & (NGU) chlamydia trachomatic, ureaplasma urealyticum, mycoplasma, trichomonas. Rx: NGU: azithromycin

70

chlamydia anomaly

chlamydia has PBPs and genes for peptidoglycan synthesis, but does not have peptidoglycan on cell wall

71

MRSA survives penicillin by..

modification of PBPs

72

Class IA antiarrhythmics (procainamide) are good for what type of arrhythmia

arising from centers of normal automaticity (rather than areas demonstrating abnormal automaticity)

73

Class IV antiarrhythmics (verapamil) are good for...

atrial tachycardia (i.e. supraventricular tachycardia, bc slows conduction through AV node)

BAD for ventricular tachycardia; exacerbates

74

use of adenosine

paroxysmal supraventricular tachycardia

75

digoxin as an antiarrythmic

slow conduction through AV node

76

Labetolol mechanism & use

blocks alpha and beta adrenergics (decreased PVR, HR, contractility, slow AV conduction). used for refractory HTN, hypertensive urgency / emergency, and patients with pheo

77

Rx: ventricular tachycardia

amiodarone (class III) (used to be lidocarine class IB)

78

Niacin/nicotinic acid/B3 side effects...

acute flare of gouty arthritis (hyperuricemia),
facial flushing (cutaneous vasodilation Rx: aspirin)
hyperglycemia (acanthosis nigricans)
heptatitis

79

Mechanism of Niacin/nicotinic acid/B3

decrease hepatic synthesis of TGs and VLDL, increasing HDL

80

Drugs that increase risk of gouty attacks

HCTZ, cyclosporine, pyrazinamide, Niacin

81

Statin side effects

hepatitis, myopathy

82

First-line Rx: hypertriglyceridemia & side effects

fibrates; gallstones & myopathy (worse w/ statins)

83

Ezetimibe effect

inhibit intestinal absorption of cholesterol

84

Bile acid-binding resins (cholestyramine) side effects

GI upset
Hypertriglyceridemia
malabsorption

85

Acute monoarticular arthritis in septic arthritis vs. gout / pseudogout

septic arthritis (gonococcus) has high WBC (100,000) while gout / pseudogout has <20,000

86

MDD diagnosis vs. Dysthymic

5 symptoms of SIG-E-CAPS for at least 2 wks w/ depressed mood or anhedonia

vs. dysthmic disorder: depressed mood for >2yrs w/ 2 symptoms

both respond to antidepressants

87

Borderline personality disorder

instability in relationships and marked impulsivity
splitting: swing from scorning to idealizing
suicidal / self-mutilating

88

Manifestation of transplant rejection
- hyperacute
- acute
- chronic

- vascular fibrinoid necrosis; neutrophil infiltrate; thrombosis; infarction
- dense interstitial T-cell infiltrate (cell-mediated) OR vasculitis (Ab: in between hyperacute/chronic)
- obliterative intimal smooth muscle hypertrophy and fibrosis

89

Lung mass w/ hyponatremia =

SIADH, EUVOLEMIC
(transient subclinical hypervolemia --> production of natriuretic peptides --> excretion of sodium)

90

Hyponatremia urine osmolarity DDx (2)

- inappropriately concentrated >100mOsm = SIADH
- maximally dilute <100mOsm = polydypsia (appropriately low ADH)

91

Course of adult polycystic kidney disease

asymptomatic; progressively worsening uremia. has renal, pancreatic, and hepatic cysts

92

Risk during pelvic surgery (esp hysterectomy)

ligation of ureter, which runs posterior to uterine artery (ligated during hysterectomy for invasive cervical cancer)

93

Vesicoureteral reflex can occur after what surgeries (2)

prostatectomy or bladder surgery

94

Differentiate (3) Lambert-Eaton from Myasthenia Gravis

LEMS has...
(1) hyporeflexia or areflexia
(2) autonomic symptoms (dry mouth, impotence)
(3) better with stimulation / at the end of the day

95

Myasthenia gravis is associated with what endocrine abnormality, and how does MG happen?

thymoma / thymic hyperplasia
(MG is NOT inherited acquired autoimmune disease)

96

Polymyositis (3 characterizations)

idiopathic inflammatory myopathy characterized by (1) bilateral proximal muscle weakness (2) elevated creatinine kinase (3) electromyographic abnormalities

97

Polymyalgia rheumatica (PMR) (2 characterestics)

sudden onset of stiffness, pain, and tenderness of musculature (esp shoulders, hips, neck, torso)
- classically elevated ESR

98

Amyotrophic lateral sclerosis

(1) upper motor neuron disease -- hyperreflexia, spasticity
(2) lower motor neuron disease -- atrophy, fasiculation

99

Guillain-Barre syndrome; onset and progression

acute post-infectious polyneuropathy (often after Campylobacter jejuni). progressive ascending paralysis

100

Half of all LEMs have...

malignancy (small cell carcinoma usu)

101

Localized amyloidosis in cardiac atria (isolated atrial amyloidosis; form of senile cardiac amyloidosis)

Natiuretic peptide
IAA risk increases w/ age ( >90% by 90)
senile cardiac amyloidosis: transthyretin, also in brain

102

primary systemic amyloidosis deposits

immune globulin light chains (primarily lambda); in mesodermal tissue (heart, muscle, tongue)

103

BRCA-1 gene location and action

AD, chr. 17, tumor supressor; control cell cycle & role in gene repair & transcription

104

APC gene mutation associated w/..

decreased expression of D-cadherin adhesion molecule

105

genome recombination

two defective virus co-infect same host cell yielding cytopathic wild-type genome. exchange of genes between two chromosomes via crossing over within homologous regions

106

viral reassortment

exchange of whole genome sequences

107

transformation

uptake of naked DNA by prokaryotic cell

108

phenotypic mixing

co-infection of a host cell by two viral trains, resulting in a virion w/ nucleocapsid proteins from one strain and genome of other strain (alters infectivity)

109

viral interference

one virus inhibits the replication/release of a second virus infecting the same cell

110

sign of NE extravasation & antidote

cold, hard, pale IV site --> intense alpha-1 vasoconstriction --> local tissue necrosis. infuse phentolamine (reversible alpha-1 blocker)

111

lidocaine is less effective in...

acidic, ischemic tissue (becomes charged)