USMLE > DIT I: Foundations > Flashcards

DIT I: Foundations Flashcards

(70 cards)

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1
Q

Name the embryonic tissue: epidermis, hair, nail, mammary gland, ant pituitary, lens, inner ear, teeth enamel, anal canal distal to pectinate

A

Surface ectoderm

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2
Q

Name the embryonic tissue: Schwann cells, glial cells, meninges, melanocytes, adrenal medulla, spiral septum, dorsal root ganglia

A

Neural crest cells

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3
Q

Name the embryonic tissue: CNS, retina, post pituitary, pineal body

A

Neural tube

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4
Q

Name the embryonic tissue: nucleus pulposis

A

Notochord

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5
Q

Fetal placental structure that secretes hCG

A

Syncytiotrophoblast

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6
Q

Maternal component of the placenta

A

Decidua basalis

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7
Q

3 germ layers that derive from epiblast

A

Ectoderm, mesoderm, endoderm

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8
Q

Teratogenic effect of: ACE inhibitors

A

Renal malformations

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9
Q

Teratogenic effect of: aminoglycosides

A

Ototoxicity, CN VIII damage

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10
Q

Teratogenic effect of: fluoroquinolones

A

Cartilage damage

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11
Q

Teratogenic effect of: cyclophosphamide

A

Ear/facial abn, limb hypoplasia, absence of digits

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12
Q

Teratogenic effect of: methotrexate

A

NTDs, abortion

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13
Q

Teratogenic effect of: tetracyclines

A

Discoloured teeth

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14
Q

Teratogenic effect of: carbamazepine and valproic acid

A

NTDs

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15
Q

Teratogenic effect of: phenytoin

A

Fetal hydantoin syndrome

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16
Q

Teratogenic effect of: lithium

A

Ebstein anomaly (tricuspid valve displaced downward into RV)

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17
Q

Teratogenic effect of: statins

A

CNS and limb abn

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18
Q

Teratogenic effect of: warfarin

A

Facial/limb/CNS abn, spontaneous abortion

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19
Q

Teratogenic effect of: isotretinoin

A

Spontaneous abortions

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20
Q

Teratogenic effect of: diethylstilbestrol (DES)

A

Clear cell vaginal adenocarcinoma

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21
Q

Teratogenic effect of: thalidomide

A

Phocomelia (limb hypoplasia)

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22
Q

By which week after conception is there fetal movement?

A

Week 8

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23
Q

By which week after conception does fetal genitalia take on visible characteristics?

A

Week 10

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24
Q

1 cause of intellectual disability in U.S.

A

Fetal Alcohol Syndrome

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25
Smooth philtrum, thin upper lip, small palpebral fissures with wideset eyes, cleft lip/palate, developmental delay, microcephaly, holoprosencephaly
Fetal Alcohol Syndrome
26
Role of SHH gene in embryogenesis; what does a mutation cause?
Buds of limbs at zone of polarizing activity, organizes embryo in anterior --> posterior direction. Mut = holoprosencephaly
27
Role of Wnt7 gene in embryogenesis
Organization along dorsal-ventral axis
28
Role of Fgf7 gene in embryogenesis; what does a mutation cause?
Limb lengthening. Mut = short limbs, mut in Fgf receptor 3 = achondroplasia
29
Most common cause of congenital malformations in the U.S.
Alcohol use in pregnancy
30
Embryological origin of tissue just proximal to pectinate line and just distal
Prox = endoderm. Distal = surface ectoderm
31
Nuclear localization signals are rich in which 3 AAs?
Lys, Arg, Pro (+vely charged, can bind to -ve DNA)
32
What enzyme degrades cyclins?
Ubiquitin protein ligase
33
Which tumour suppressor proteins regulate G1 --> S?
Rb, p53
34
Which tumour suppressor proteins regulate G2 --> M?
p53
35
Which cyclins + cyclin-dependent kinases regulate G1 --> S?
Cyclin D + CDK4 --> Cyclin E + CDK2
36
Which cyclins + cyclin-dependent kinases regulate G2 --> M?
Cyclin A + CDK2, Cyclin B + CDK1 (with cdc 25)
37
Coat protein II (COP-II) vs COP-I
COP-II: anterograde trafficking (ER --> cis Golgi). COP-I: retrograde (Golgi --> ER)
38
Which AAs does the Golgi apparatus modify, mainly? (3)
Asn, Ser, Thr
39
3 methods of protein degradation
Lysosomal degradation, proteosomal degradation (via ubiquitin tags), Ca2+ dependent enzymes
40
Deficiency in mannose phosphorylation, death by age 8, corneal clouding, coarse facies, hepatosplenomegaly, skeletal abnormalities, restricted joint movements
I-cell disease (No mannose-6-phosphate tagging --> lysosomal proteins secreted out of cell)
41
Where is vimentin found, and what tumours can a stain of it be used to detect?
Connective tissue (fibroblasts, leukocytes, endothelium). Sarcomas, some carcinomas
42
Where is desmin found, and what tumours can a stain of it be used to detect?
Muscle cells (smooth, skeletal, heart). Myosarcomas
43
Where is cytokeratin found, and what tumours can a stain of it be used to detect?
Epithelial cells (keratin in demosomes and hemidesmosomes). Carcinomas
44
Where is glial fibrillary acid proteins (GFAP) found, and what tumours can a stain of it be used to detect?
Astrocytes, Schwann cells, other neuroglia. Astocytomas (eg glioblastoma)
45
Where is peripherin found?
Neurons
46
Where are neurofilaments (L, M, H molecular weight) found, and what tumours can a stain of it be used to detect?
Axons within neurons. Neuroblastoma, primitive neuroectodermal tumour.
47
Where are nuclear lamins (A, B, C) found?
Nuclear envelope and DNA within
48
Molecular motor proteins: dynein vs kinesin
Kinesin walks toward (+) end, usually anterograde. Dynein walks toward (-) end, usually retrograde.
49
Situs inversus, bronchiectasis, chronic sinusitis
Kartagener syndrome (primary ciliary dyskinesia): due to dynein arm defect
50
How does Rb protein regulate cell cycle?
Phosphorylation of Rb --> allows E2F txn factor to influence txn (G1 --> S)
51
How does p53 influence cell cycle?
Controls activation of p21
52
Subunits of insulin receptor and their function
2 alpha units bins extracellular ligand, 2 beta subunits have tyrosine kinase activity.
53
Role of dynamin in receptor-mediated endocytosis
Pinches off vesicle formed by clathrin-coated pit
54
What is the defect in familial hypercholesterolemia?
Mutant LDL receptor lacks coated-pit binding site but retains functioning LDL-binding site --> can bind LDL but unable to ingest it
55
MOA: zileuton
Inhibits lipoxygenase --> decreased leukotrienes
56
MOA: zafirlukast & montelukast
Inhibit leukotriene receptors
57
Major anti-apoptotic regulator of mitochondrial permeability
Bcl-2
58
What gene product creates channels in mitochondrial membrane, and how is it activated?
Bax (pro-apoptotic), activated by DNA dmaage or apoptotic signal
59
What substance is released from mitochondria in the process of apoptosis, and what does it activate?
Cytochrome C, activates caspases
60
Define: pyknosis, karyorrhexis
Pyknosis = condensation of nuclear chromatin. Karryorhexis = nuclear fragmentation.
61
What substances do cytotoxic T cells and NK cells use to induce apoptosis in cells infected with a virus?
Perforin, granzyme B
62
4 stages of neutrophil extravasation
Rolling, tight binding, diapedesis, migration
63
Which adhesion molecules mediate neutrophil rolling?
Selectins on endothelium (E, P, and L)
64
Which adhesion molecules mediate neutrophil tight binding?
ICAM-1 on endothelium + LFA-1 on leukocytes
65
Which adhesion molecules mediate neutrophil diapedesis?
PECAM-1
66
Neutrophil chemotactic signals (4)
C5a, IL-8, LTB4, kallikrein
67
Disease and defect: delayed separation of umbilicus in newborns, recurrent bacterial infections
Leukocyte adhesion deficiency syndrome: due to abn integrin (LFA-1) affecting tight binding step
68
Things that lower ESR
abnormally shaped RBCs (eg sickle), polycythemia
69
What can elevated CRP predict?
MI, stroke, PAD, sudden cardiac death
70
What cell generates fibrinogen and CRP?
Hepatocyte

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