uworld missed concepts Flashcards

1
Q

ventromedial hypothalamic nucleus

A

mediates satiety (destruction makes you always hungry)

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2
Q

lateral hypothalamic nucleus

A

mediates hunger (destruction makes you never hungry)

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3
Q

anterior hypothalamic nucleus

A

mediates heat dissipation (destruction makes you always hot)

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4
Q

posterior hypothalamic nucleus

A

mediates heat conservation (destruction makes you always cold)

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5
Q

arcuate hypothalamic nucleus

A

secretes dopamine (inhibits prolactin), secretes GHRH

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6
Q

medial preoptic hypothalamic nucleus

A

secretes GnRH, regulates sexual behavior

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7
Q

paraventricular hypothalamic nucleus

A

secretes oxytocin, TRH, CRH, some ADH

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8
Q

supraoptic hypothalamic nucleus

A

secretes ADH, some oxytocin

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9
Q

suprachiasmatic hypothalamic nucleus

A

circadian rhythm regulation, pineal gland function (melatonin)

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10
Q

ETEC

A

enterotoxigenic - traveler’s diarrhea (watery)
LT enterotoxin (cholera-like toxin, heat labile, increases cAMP)
ST enterotoxin (heat stable, increases cGMP)
colonizes and adheres to small intestine enterocytes via pili
increased chloride secretion and decreased sodium reabsorption by enterocytes

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11
Q

EHEC

A

enterohemorrhagic - bloody diarrhea from contaminated, undercooked meat
shiga-like toxin (inactivates 60s ribosomal subunit in host cells)

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12
Q

anaerobic glycolysis

A

occurs in oxygen-poor states
glucose -> pyruvate -> lactate in the cytosol
net 2 ATP / glucose
occurs in cancer cells and stem cells even in oxygen-rich states (causing tumor cells to take up more glucose, rapid cell division)

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13
Q

oxidative phosphorylation

A

occurs in oxygen-rich states
glucose -> pyruvate -> acetyl CoA -> TCA cycle -> NADH -> ETC
net 36 ATP / glucose

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14
Q

PDE5 inhibitors (sildenafil, tadalafil)

A

erectile dysfunction drugs
increase cGMP (mediates vascular smooth muscle relaxation) in penile corpora
side effect: can also inhibit PDE6 in retina causing vision to tint blue, sudden monocular vision loss with afferent pupillary defect (ischemic optic neuropathy)

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15
Q

phenotypic mixing

A

occurs when a host cell is co-infected with two viral strains
genome of virus A becomes coated with the surface proteins of virus B
progeny of virus A will have type A coat (not type B)

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16
Q

recombination

A

exchange of genes between 2 chromosomes by crossing over within regions of significant base sequence homology

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17
Q

reassortment

A

viruses with segmented genomes exchange an entire segment of genetic material
has potential to cause antigenic shift

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18
Q

complementation

A

1 of 2 viruses infecting a cell has a mutation that results in a nonfunctional protein, the nonmutated virus complements the mutated one by making a functional protein that serves both viruses

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19
Q

interference

A

one virus in a cell inhibits the release or replication of a second virus in the cell

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20
Q

transformation

A

incorporation of viral DNA into a host cell genome, altering genetic composition of host cell but not virus

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21
Q

adenosine action

A

vasodilation

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22
Q

nitric oxide action

A

vasodilation

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23
Q

atropine action

A

muscarinic antagonist

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24
Q

trisomy 13

A

patau syndrome
defect in fusion of prechordal mesoderm (midline defects)
severe intellectual disability, rocker-bottom feet, microphthalmia, microcephaly, holoprosencephaly, cleft lip/palate, polydactyly, cutis aplasia, polycystic kidney disease, omphalocele

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25
Q

trisomy 18

A

edwards syndrome
prominent occiput, rocker-bottom feet, intellectual disability, clenched fists with overlapping fingers, low-set ears, micrognathia, congenital heart disease, omphalocele, myelomeningocele
all prenatal screening markers are decreased

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26
Q

trisomy 21

A

down syndrome
intellectual disability, flat facies, prominent epicanthal folds, single palmar crease, incurved 5th finger, gap between first two tows, duodenal atresia, hirschprung disease, congenital heart disease, brushfield spots, early-onset alzheimer’s disease, increased risk of AML/ALL
increased hCG and inhibin in prenatal screening

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27
Q

affinity maturation

A

B cell process
process of enhancing the hypervariable region antigen binding affinity that occurs after initial binding of antigen to membrane-bound immunoglobulin on a naïve B lymphocyte and subsequent migration of that B-lymphocyte to a lymph node
results in new immunoglobulins with similar, better, or worse affinity for the antigen; only antibodies with better affinity will be selected for
occurs within the germinal center of the lymph node

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28
Q

isotype switching

A

B cell process
switches out the heavy chain of an antibody

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29
Q

negative selection

A

occurs in the thymic medullary epithelial and dendritic cells (after positive selection)
T cells with TCRs that bind with high affinity to self-antigen or self-MHC undergo apoptosis (eliminates overly-autoreactive cells, prevents autoimmunity)

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30
Q

positive selection

A

occurs in the thymic cortex
only double positive (CD4+/CD8+) T cells expressing TCRs that are able to self-bind MHC on cortical epithelial cells are allowed to survive (eliminates non-reactive cells)

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31
Q

sulfonylurea

A

stimulates beta cells to secrete insulin
side effects: hypoglycemia, dark colored urine, upset stomach, skin reactions

32
Q

congenital syphilis

A

rhinorrhea, maculopapular rash, metaphyseal erosions, periosteal inflammation of long bones, pathologic fractures, swelling, pain, and limited movement of extremities, fever, hepatosplenomegaly, lymphadenopathy

33
Q

neonatal chlamydia

A

conjunctivitis or pneumonia

34
Q

neonatal nosocomial staph aureus

A

osteomyelitis w fever; higher risk in prematurity, central line

35
Q

12-24 hours post-ischemic stroke

A

red neurons (eosinophilic cytoplasm, pyknotic nuclei, loss of nissl substance)

36
Q

24-72 hours post-ischemic stroke

A

neutrophilic infiltration

37
Q

3-7 days post-ischemic stroke

A

macrophage/microglia infiltration, phagocytosis begins

38
Q

1-2 weeks post-ischemic stroke

A

reactive gliosis, vascular proliferation around necrotic area (liquefactive necrosis)

39
Q

> 2 weeks post-ischemic stroke

A

glial scar formation (cystic area surrounded by dense glial fibers)

40
Q

HHV8

A

causes Kaposi sarcoma in HIV+ patients

41
Q

molluscum contagiosum

A

firm, shiny round papules with a central indentation
caused by poxvirus

42
Q

first-line treatment for gout attack

A

NSAIDs (inhibits COX, decreases prostaglandins)

43
Q

why are people with silicosis predisposed to TB

A

impaired macrophage function

44
Q

chronic granulomatous disease

A

x-linked recessive mutation of NADPH oxidase -> decreased radical oxygen species -> inhibition of phagocytic intracellular killing
recurrent infections of lungs, skin, liver, lymph nodes
diffuse granuloma formation

45
Q

infantile hemangioma

A

benign proliferation of endothelial cells; lobules of densely packed capillaries
appears days to weeks after birth, proliferates in infancy, involutes and regresses in size throughout childhood

46
Q

abciximab

A

glycoprotein IIb/IIIa receptor antagonist (inhibits binding of platelet to fibrinogen)
used for treatment of unstable angina and acute coronary syndrome

47
Q

glanzmann thrombasthenia

A

autosomal recessive disorder caused by defective glycoprotein IIb/IIIa on platelet

48
Q

short-acting benzos (<6h)

A

triazolam, midazolam

49
Q

intermediate-acting benzos (6-50h)

A

clonazepam, oxazepam, lorazepam, alprazolam (COLA)

50
Q

long-acting benzos (>50h)

A

diazepam, flurazepam, chlordiazepoxide

51
Q

pharyngeal/aortic arch 1

A

trigeminal nerve (CN V), maxillary artery

52
Q

pharyngeal/aortic arch 2

A

facial nerve (CN VII), stapedial artery (regresses)

53
Q

pharyngeal/aortic arch 3

A

glossopharyngeal nerve (CN IX), common carotid artery, proximal internal carotid artery

54
Q

pharyngeal/aortic arch 4

A

superior laryngeal branch of the vagus nerve (CN X), arch of the aorta, subclavian arteries

55
Q

pharyngeal/aortic arch 5

A

obliterated

56
Q

pharyngeal/aortic arch 6

A

recurrent laryngeal branch of the vagus nerve (CN X), pulmonary arteries, ductus arteriosus

57
Q

what causes spina bifida

A

failure in neurulation (vertebral arch fusion)

58
Q

proto-oncogenes

A

one hit causes an oncogenic gain of function
RAS, MYC, ERBB1(EGFR), ERBB2(HER2), ABR, BRAF

59
Q

tumor suppressor genes

A

two hit causes loss of function (no longer protective)
BRCA 1/2, APC, TP53, RB, WT1, VHL

60
Q

RAS

A

proto-oncogene
GTP binding protein
cholangiocarcinoma, pancreatic adenocarcinoma

61
Q

MYC

A

proto-oncogene
transcription factor
Burkitt lymphoma

62
Q

ERBB1 (EGFR)

A

proto-oncogene
receptor tyrosine kinase
lung adenocarcinoma

63
Q

ERBB2 (HER2)

A

proto-oncogene
receptor tyrosine kinase
breast cancer

64
Q

ABL

A

proto-oncogene
nonreceptor tyrosine kinase
chronic myelogenous leukemia

65
Q

BRAF

A

proto-oncogene
ras signal transduction
hairy cell leukemia, melanoma

66
Q

BRCA 1/2

A

tumor suppressor gene
DNA repair genes
breast cancer, ovarian cancer

67
Q

APC (beta catenin)

A

tumor suppressor gene
wnt signaling pathway
colon cancer, gastric cancer, pancreatic cancer (familial adenomatous polyposis)

68
Q

TP53

A

tumor suppressor gene
genomic stability
most cancers (Li Fraumeni syndrome)

69
Q

RB

A

tumor suppressor gene
G1/S phase transition inhibitor
retinoblastoma, osteosarcoma

70
Q

WT1

A

tumor suppressor gene
urogenital differentiation
wilms tumor (nephroblastoma)

71
Q

VHL

A

tumor suppressor gene
ubiquitin ligase component
renal cell carcinoma (Von Hippel Lindau syndrome)

72
Q

MEN 1

A

MEN1 tumor suppressor gene
pituitary tumors, pancreas endocrine tumors, parathyroid adenomas

73
Q

MEN2a

A

RET protooncogene
parathyroid hyperplasia, medullary thyroid carcinoma, pheochromocytoma

74
Q

MEN2b

A

RET protooncogene
medullary thyroid carcinoma, pheochromocytoma, mucosal neuroma (oral/intestinal lesions), marfanoid habitus

75
Q

Lynch syndrome

A

colorectal cancer, uterine cancer, stomach cancer, liver cancer, kidney cancer, brain cancer, skin cancer