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Flashcards in UWorld Deck (494):
1

Pregnancy termination followed by fever, uterine tenderness, foul-smelling discharge

S. aureus or E. coli (septic abortion)

2

Non-pathogenic strain of Flu virus cultured with pathogenic strain, and gains some pathogenic characteristics

Reassortment / genetic shift (segmented genome)

Genetic segments mix → progeny will have the new characteristics

3

Host cell co-infected w/2 viral strains → progeny virions contain unchanged parental genome from one strand and envelope proteins from other strain

Phenotypic mixing

genome unchanged, so subsequent progeny will NOT retain traits

4

Point mutations in virus genes that slightly alter protein products

Antigenic Drift

5

Inflammatory or infectious GI bug followed by continued diarrhea

Secondary lactose intolerance from damage to small intestine microvilli

6

Where is the obstruction if the lateral and 3rd ventricles are enlarged and 4th ventricle is normal?

Cerebral aqueduct

7

Where is the obstruction if all 4 ventricles are enlarged?

Foramen of Magendie and Luschka

8

Where is the obstruction if a lateral ventricle is enlarged?

Foramen of Munro

9

Inferior surface of heart comprised of?

L ventricle (2/3) and R ventricle (1/3), separated by posterior interventricular groove

10

Occlusion of which coronary aa will cause inducible ischemia of inferior surface of heart?

Posterior descending brr of R coronary aa

11

Occlusion of which coronary aa will cause ischemia in anterior 2/3 IV septum?

LAD

12

Occlusion of which coronary aa will cause ischmia of anterior wall of LV?

LAD

13

Occlusion of which coronary aa will cause ischemia of laterial and posterior superior walls of L ventricle?

L circumflex

14

Which coronary aa may provide collateral circulation if LAD is blocked?

R marginal brr of R coronary aa

15

Severe arthritis + blue-black deposits in sclerae + darkening of connective tissue + urine turns black when exposed to air

Alkaptonuria

16

Inheritance of Alkaptonuria

AR

17

Enzyme deficient in Alkaptonuria

Homogentisic acid dioxygenase (normally metabolizes homogentisic acid → maleylacetoacetate; part of tyrosine metabolism pathway)

18

Wrist bone most often affected in fall on outstretched hand

Scaphoid (more lateral, articulates w/radius) or Lunate (more medial, articulates w/radius)

19

Mechanism of eosinophil parasite defense

Ab-dependent cell-mediated cytotoxicity

  • TH2 and mast cells produce IL-5 to activate eosinophils
  • Parasite coated w/IgG and IgE
  • Ab's bind to eosinophil Fc receptors
  • Eosinophil degranulation

20

IL-2 effects

  • NK cell activation
  • Monocyte activation
  • TH cell proliferation & differentiation
  • B cell division
  • T cell growth & IFN-gamma secretion

21

IL-2 produced by?

TH cells

22

Major mechanism of IL-2 anti-tumor effects?

Increased T cell and NK cell activity

23

Most common cause of bloody nipple discharge

Intraductal papilloma

24

Intraductal papilloma histology

Proliferation of papillary cells in cyst wall or duct, poss w/focal atypia

25

Candida antigen skin test response mediated by which cells

Macrophages, CD4+, CD8+ cells (Type 4 HS)

26

Failure to respond to Candida antigen testing suggests?

SCID

27

Timing of hyperacute transplant rejection

Minutes to hours

28

MOA of hyperacute transplant rejection

Preformed Ab's against graft (Type 2 HS)

29

Morphology of hyperacute transplant rejection

  • Gross mottling & cyanosis
  • Arterial fibrinoid necrosis
  • Capillary thrombotic occlusion

30

Timing of acute transplant rejection

6mos

31

MOA of acute transplant rejection

Exposure to donor Ag's induces host immune cell activation

32

Morphology of acute transplant rejection

Humoral:

  • C4d deposition
  • Neutrophilic infiltrate
  • Necrotizing vasculitis

Cellular:

  • Lymphocytic interstitial infiltrate
  • Endothelitis

33

Timing of chronic transplant rejection

Months to years

34

MOA of chronic transplant rejection

Chronic, low-grade immune response -- refractory to immunosuppressants

35

Morphology of chronic transplant rejection

  • Vascular wall thickening & luminal narrowing
  • Interstitial fibrosis
  • Parenchymal atrophy

36

Graft-vs-Host Disease

  • Most often following BM transplant
  • Donor T-cells attack host organs
  • Diffuse maculopapular eruption starting on palms, soles, back, neck

37

Predominant immune cell type in broncheolar lavage fluid in sarcoidosis?

CD4+

38

Steps in granuloma formation in sarcoidosis

Cell-mediated immunity:

  • TH1 cells make IL-2 and IFN-gamma
  • IL-2 stimulates more TH1 cell proliferation
  • IFN-gamma activates Macrophages
  • Macrophages promote granuloma formation

Granulomas = alveolar & interstitial accumulations of CD4+ cells

39

TH2 cell function

Humoral immune response

  • IL-4 → B cell IgE production
  • IL-5 → Eosinophil activation + B cell IgA production

40

Flattening of deltoid + sensory loss in overlying skin suggests what kind of injury?

Anerior dislocation of humerus

41

Nerve most commonly injured in anterior shoulder dislocation?

Axillary nn

42

Most common mechanism of anterior humerus dislocation injury?

Blow to externally rotated & ABducted arm (throwing motion)

43

At L4-L5, IVC is formed by what vessels?

Union of R & L common iliac vv

44

Osgood-Schattler Disease

Overuse injury of secondary ossification center (apophysis) of tibial tubercle -- common cause of knee pain in adolescent atheletes

45

Patellar ligment lower insertion point

Tibial tubercle

46

What ligament attaches at the anterior intecondylar area of tibia?

ACL

47

MOA of noise-induced hearing loss

trauma to stereociliated hair cells of Organ of Corti

48

Bilateral high-frequency hearing loss suggests what kind of injury?

Prolonged noise exposure → damage to Organ of Corti

49

Hearing loss affecting air conduction across all frequencies suggests what kind of defect?

Middle ear ossicle problems (otosclerosis)

50

Tympanic membrane rupture causes what kind of hearing loss?

Unilateral conductive loss

51

L 12th rib fracture likely to injure what organ?

L kidney

52

Gastric ulcers likely to penetrate which arteries?

Most ulcers are on lesser curve of stomach → R & L gastric aa

53

Aspiration while lying supine usually affects which lung area?

R posterior upper lobes & superior lower lobes

54

Aspiration while upright or semi-recumbent usually affects which lung area?

Basilar segments of lower lobes

55

Transesophageal echocardiography probe facing anteriorly is closest to which heart chamber?

L atrium

56

Fracture to fibular neck injures what nerve?

Common peroneal nn

57

Effects of injury to common peroneal nn?

  • Weakness of dorsiflexion (deep) → foot drop
  • Weakness of foot eversion (superficial)
  • Loss of sensation over dorsum of foot
  • Inability to gently lower forefoot on heel strike → "Steppage gait" w/"foot slap"

58

Air in gallbladder and biliary tree suggests obstruction where?

Ileum (gallstone ileus)

Stone passes thru cholecystenteric fistula into small bowel

59

Pancreatitis and/or cholangitis suggests obstruction where?

Common bile duct

60

Lead toxicity affects which enzymes?

Ferrochelatase and ALAD → anemia

61

Elevated zinc protoporphyrin levels suggest?

Lead poisoning

Ferrochelatase/ALAD inhibition → protoporphyrin can't combine w/Fe2+ → protoporphyrin incorporates Zn2+ instead

62

Uroporphinogen decarboxylase defects cause?

Porphyria cutanea tarda

63

Symptoms of porphyria cutanea tarda?

  • Chronic photosensitivity w/blistering
  • Elevated urinary uroporphyrinogen

64

Porphobilinogen deaminase defects cause?

Acute intermittent porphyria

65

Acute intermittent porphyria symptoms

  • Acute attacks of abd pain
  • Neuropsychiatric symptoms
  • Red/brown urine

66

Middle meningeal aa is a brr of which major aa?

Maxillary aa

67

Pterion consists of?

Region where frontal, parietal, temporal, and sphenoid bones meet → overlies middle meningeal brr of maxillary aa

68

Steps in granuloma formation in TB

Macrophages ingest some bacteria & present Ag to naive TH cells

  • Macrophages secrete IL-12 → induce TH1 differentiation
  • TH1 cells secrete IFN-gamma → activate macrophages
  • Activated macrophages have improved ability to kill infected bacteria + secrete TNF-alpha → recruit add'l monocytes/macrophages

Granuloma (walled-off area) creation & maintenance

69

Frameshift mutation

Deletion or insertion of a number of bases not divisible by 3

70

In-frame deletion

One or more AA triplets removed → reading frame preserved

71

Missense mutation

substitution of one AA for another

72

Nonsense mutation

Single AA change that results in premature stop codon

73

Wobble hypothesis

certain tRNAs can recognize multiple different codons for the same AA

  • 1st 2 nucleotide positions require traditional base-pairing, but the 3rd is more flexible

74

Homocystinuria enzyme defect

Cystathionine beta-synthase + Vit B6

75

Homocystinuria symptoms

  • Ectopia lentis (inferior)
  • Intellectual disability
  • Marfanoid habitus
  • Thromboembolic occlusions (1° COD)

76

What feature of eukaryotic DNA replication allows it to happen quickly despite large size & complexity?

Multiple origins of replication

77

Dihydrorhodamine test

 Assesses production of superoxide radicals to test for CGD

  • Measures conversion of DHR to rhodamine
  • Deficient NADPH oxidase → decreased fluorescence

78

Axillary LN dissection can injure what nn?

Long thoracic (C5-7 roots) → impaired shoulder abduction past horizontal + winged scapula

79

Esophageal varices caused by what anastomosis?

L gastric vv → esophageal vv

80

Hemorrhoids caused by what anastomosis?

Superior rectal vv → Middle & Inferior rectal vv

81

Caput medusae caused by what anastomosis?

Paraumbilical vv → Superficial & Inferior epigastric vv

82

Ataxia-Telangiectasia

AR defect in DNA repair → DNA hypersensitivity to ionizing radiation

  • Cerebellar atrophy in 1st year of life
  • Oculocutaneous telangiectasias
  • Severe immunodeficiency → recurrent sinopulm infxns
  • Inefficienct DNA repair → increased cancer risk

83

Xeroderma pigmentosum

DNA hypersensitive to UV radiation

  • Premature skin aging
  • Increased risk skin cancer

84

Fanconi anemia caused by?

DNA hypersensitivity to cross-linking agents

85

Bloom syndrome caused by?

Generalized chromosomal instability → increased risk cancer

86

Internal hemorrhoids drain into which vv?

Middle & superior rectal vv → internal iliac & inferior mesenteric vv

87

External hemorrhoids drain into which vv?

inferior rectal vv → internal pudendal vv → internal iliac vv

88

Foreign bodies lodged in piriform recess can damage which nn and cause what symptoms?

Internal laryngeal nn (brr of superior laryngeal nn, component of CN 10) → impaired cough reflex

89

Protein cal/g?

4

90

Carbohydrate cal/g?

4

91

Fat cal/g?

9

92

EtOH cal/g?

7

93

Ulcers on posterior wall of duodenal bulb can injure which aa?

Gastroduodenal aa

94

which enzyme involved in prokaryotic DNA synthesis catalyzes formation of RNA strands?

Primase

  • RNA polymerase that synthesizes short RNA primer using separated DNA strands as templates

95

which enzyme repairs single-strand breaks in duplex DNA during replication and repair?

DNA ligase

96

3 main aa that supply GI tract?

  1. Celiac trunk
    • stomach
    • part of duodenum
    • gallbladder
    • liver
    • spleen
    • pancreas
  2. SMA:
    • 3rd part of duodenum thru proximal 2/3 of transverse colon
  3. IMA:
    • Distal 1/3 of transverse colon thru rectum

97

2 anastomoses connecting SMA and IMA?

  1. Marginal aa of Drummond
  2. Arc of Riolan

Protect intestines from ischemia!

98

Obturator nn compression symptoms

  • Weakness of thigh ADuction
  • Sensory loss over distal medial thigh

99

Embryonic precursor of ductus arteriosus?

6th aortic arch

100

Cricothyrotomy incision passes through what structures?

Superficial cervical fascia → pretracheal (deep cervical) fascia → cricothyroid membrane

101

Which aa supplies blood to liver?

Proper hepatic aa (brr of celiac trunk)

102

Rheumatoid Factor

IgM that reacts w/Fc portion of human IgG

103

Cutaneous innervation of external ear

  • External ear: Great Auricular nn, Lesser Occipital nn, Auriculotemporal nn
  • Most of ext aud canal: Auriculotemporal brr of CN V3
  • Ext portion of tympanic memb: Auriculotemporal brr of CN V3
  • Post part of ext aud canal: Small auricular brr of CN X

104

Hyperacusis caused by?

  • Injury to Stapedius nn (brr of CN 7) → Stapedius mm paralysis → Wider oscillations

OR

  • Injury to Mandibular brr of CN 5 → Tensor tympani dysfcn → Decreased sound dampening

105

Bladder extra- or intraperitoneal?

Extraperitoneal

106

Most common DNA-binding motif?

Zinc-finger → used by transcription factors

107

Hormones w/intracellular receptors

  • Steroid hormones (estrogen, aldosterone, cortisol) → nuclear receptors
  • Thyroid hormone → cytoplasmic receptor

108

How does immune response differ to live vs inactivated polivirus vaccine?

Live attenuated oral produces stronger IgA response

109

4 enzymes unique to gluconeogenesis

  1. Pyruvate Carboxylase: pyruvate → oxaloacetate (bypasses pyruvate kinase)
  2. PEP Carboxykinase: oxaloacetate → PEP (bypasses pyruvate kinase)
  3. Fructose 1,6-Bisphosphonate (bypasses phosphofructokinase)
  4. Glucose-6-Phosphatase (bypasses hexokinase)

110

Succinate dehydrogenase requires what cofactor?

FAD (derivative of riboflavin / Vit B2)

111

NADH excess will stop which TCA cycle enzymes?

  • Isocitrate dehydrogenase
  • Alpha-ketoglutarate dehydrogenase
  • Malate dehydrogenase

112

Enzyme that catalyzes formation of pigmented gallstones

Beta-glucuronidase (released by injured hepatocytes /  bacteria / C. sinensis → increases UCB levels)

113

Antiphospholipid syndrome can cause what common complications?

Recurrent miscarriages + thromboembolic events

114

most common location of neonatal interventricular hemorrhage?

germinal matrix

115

Superior gluteal nn injury symptoms

Contralateral hip drop → Trendelenburg gait (gluteus medius/minimus fail)

116

Safe injection sites in gluteal region?

Most preferred: Anterolateral region (von Hochstetter triangle)

  • Also okay: Superolateral quadrant of buttock

Other sites:

  • Superomedial quadrant: Risk injury to superior gluteal nn OR sciatic nn
  • Inferomedial or Inferolateral quadrants: Risk injury to sciatic nn

117

Acute compartment syndrome in anterior compartment of leg can affect which structures?

  • Deep peroneal nn
  • Anterior tibial aa
  • Foot extensor mm

118

Structures passing thru superior orbital fissure

  • CN 3
  • CN 4
  • CN V1
  • CN 6
  • Superior ophthalmic vv

119

Lateral ankle sprain (inversion) most commonly injures what structure?

Anterior talofibular ligament

120

Expressive aphasia

Broca's area

121

Receptive aphasia

Wernicke's area

122

Conduction aphasia

Arcuate fasciculus

123

Alpha-galactosidase A deficiency

Fabry disease

124

Fabry disease symptoms

  • Neuropathic pain
  • Angiokeratomas
  • Renal failure
  • Cardia complications
  • Cerebrovascular complications

125

Fabry disease enzyme deficiency and substance accumulation

  • Alpha-galactosidase A
  • Globotriaosylceramide (Gb3) / Ceramide Trihexoside

126

Leptin MOA

  • Decreases production of Neuropeptide Y in Arcuate nucleus of hypothalamus
  • Stimulates production of POMC in Arcuate nucleus of hypothalamus → Alpha-MSH (via POMC cleavage)

Result: satiety

127

Proximal ureter blood supply

Renal aa branches

128

Distal ureter blood supply

Superior vesical aa

129

Middle ureter blood supply

Highly variable and anastomotic; may include gonadal, common iliac, internal iliac, uterine, aorta

130

Appendix removal can damage which nerve and cause what symptoms?

  • Iliohypogastric nn
  • Decreased sensation / burning pain in suprapubic region

131

Sensory innervation of lateral forearm

Musculocutaneous nn

  • C5-C7 roots
  • Biceps mm
  • Brachialis mm
  • Coracobrachialis mm

132

Midshafte humerus injury will affect which nerve?

Radial nn

133

Radial nn damage symptoms

  • Weakness with wrist & finger extension (wrist drop)
  • Sensory loss in posterior arm & forearm

134

Median nn damage symptoms

  • Weakness on wrist flexion
  • Weakness on thumb opposition

135

Ulnar nn damage symptoms

  • Weakness of wrist flexion
  • Weakness in finger aBduction
  • Waekness in thumb aDduction

136

Enteropeptidase

  • Produced by duodenum
  • Trypsinogen → trypsin

137

Trypsin function

  • Degrades complex peptides to dipeptides + AAs
  • Activates other proteases (carboxypeptidase, elastase, chymotrypsin)

138

Telomerase

  • Ribonucleoprotein
  • Adds TTAGGG repeats to 3' end of chromosomes
  • Reverse transcriptase activity
  • TERT + TERC subunits
  • Highly expressed in stem cells → promotes controlled proliferation

139

Location of lung apices

Extend above clavicle and 1st rib thru superior thoracic aperture → injury here may damage pleura, cause (tension) pneumothorax, hemothorax

140

Candida local vs systemic defense

  • Local: T cells (HIV pts)
  • Systemic: Neutrophils (IC pts)

141

Hypoxia can cause acidosis via inhibition of which enzyme?

Pyruvate dehydrogenase (inhibited by intracellular NADH accumulation → increased lactate dehydrogenase activity → lactic acidosis)

142

Procollagen peptidase deficiency

  • Normally cleaves terminal propeptides from procollagen in extracellular space
  • Ehlers-Danlos

143

Essential AA in pts w/homocystinuria

Cysteine

144

Elevated methionine levels in young child suggest?

Homocystinuria: cystathionine synthase deficiency → homocysteine buildup → prothrombotic

145

Bloom Syndrome

  • BLM gene mutations (AR)
  • Helicase dysfcn
  • Chromosomal instability
  • Growth retardation + facial anomalies + photosensitive skin rash + immunodeficiency

146

Tibial nn function

  • Foot plantarflexion
  • Foot inversion
  • Toe flexion
  • Sole sensation

147

Injury to what nerve causes foot dorsiflexion and eversion?

Tibial nn

148

Internal capsule of brain

  • Posterior limb: Separates globus pallidus and putamen from thalamus
    • Corticospinal mortor and somatic sensory fibers
    • Visual and auditory fibers
  • Genu: Btwn anterior and posterior branches
    • Corticobulbar fibers
  • Anterior limb: Separates caudate nucleus from globus pallidus and putamen
    • Thalamocortical fibers

149

Complication of scaphoid fracture

Avascular necrosis

150

Pathway that inhibits prolactin?

Tuberoinfundibular (blocked by many antipsychotics → hyperprolactinemia)

151

Which step in mRNA processing/handling occurs only in cytoplasm?

Interaction w/P bodies: distinct foci in eukaryotic cells involved in mRNA regulation, turnover/degradation, and storage

152

Loss of anal pinprick sensation suggests damage to which nerve roots?

S2-S4

153

Cytokine that promotes class-switching to IgE?

IL-4 (produced by TH2 cells)

154

B6 is a cofactor for which 2 common AA reactions?

  1. Transamination
  2. Decarboxylation

155

Which muscle causes superior displacement of medial fragment in clavicle fracture?

SCM

156

Prolonged kneeling can irritate which bursa?

Prepatellar

157

Pancoast tumor

  • Non-small-cell lung cancer
  • Arise near superior sulcus
  • Brachial plexus compression →
    • Ipsilateral shoulder pain
    • UL parasthesias
    • Areflexic arm weakness
  • Cervical symp ganglia involvement → Horner's Synd

158

ST elevations in leads I, aVL, V5, V6

Left circumflex aa occlusion → lateral aspecf of L ventricle

159

ST elevations in leads V1-V4

Proximal LAD occlusion → anterior aspect of L ventricle + IV septum

160

ST elevations in leads V3-V4

Distal LAD occlusion → anterior aspect of L ventricle + IV septum

161

ST elevation in V1-V4, V5-V6, I, and aVL

L main coronary aa occlusion → anterolateral infarct

162

ST elevations in leads I, III, and aVF

R coronary aa occlusion → inferior infarct

163

Sudden upward stretching of arm at shoulder can injure what structure?

Lower trunk of brachial plexus (C8-T1) → finger clumsiness + total claw hand deformity (Klumpke's Palsy)

164

Blunt aortic injury happens most often at which location?

Aortic isthmus: tethered by ligamentum arteriosum, relatively immobile compared to adjacent descending aorta

165

Unilateral temporal lobe injury likely to cause what VF defect?

Meyer's loop injury → Contralateral superior quadrantanopia

166

Orbital floor fractures can cause what nerve symptoms?

Infraorbital nn → inferior rectus entrapment + parathesias in:

  • Upper cheek
  • Upper lip
  • Upper gingiva

167

Indirect inguinal hernia location

lateral to inferior epigastric vessels → can continue into scrotum

168

Direct inguinal hernia location

medial to inferior epigastric vessels → do NOT protrude into scrotum

169

Vertical diplopia

CN 4 lesion

170

Diplopia resuling in trouble reading, going down stairs

vertical diplopia - CN 4 lesion

171

horizontal diplopia

CN 3 or CN 6 lesion

172

Pancreas: peritoneal or retroperitoneal?

  • Retro: head, neck, body
  • Peritoneal: tail

173

hemorrhage location w/arterial puncture above inguinal ligament?

retroperitoneal

174

niacin synthesis precursor?

tryptophan

175

niacin deficiency

pellagra: dermatitis, diarrhea, dementia

176

location of collagen hydroxylation

RER

177

B cell markers

  • CD19
  • CD20
  • CD21

178

median nn courses through which mm near wrist?

Flexor digitorum superficialis + flexor digitorum profundus

179

proximal median nn lesion symptoms

  • sensory loss in 1st 3 digits
  • weakness on thumb opposition/flexion
  • "preacher's hand" on attempt to make a fist

180

median nn lesion @ wrist

  • sensory disturbance in 1st 3 digits
  • normal sensation in thenar eminence
  • preserved flexion of 2nd/3rd digits & wrist

181

musculocutaneous nn lesion

  • paralysis of elbow flexors (biceps, brachialis, coracobrachialis)
  • loss of sensation in lateral forearm

182

ulnar nn lesion

  • loss of sensation in medial 1.5 digits of hand
  • weakness on wrist flexion/aDduction
  • weakness on finger aB/aDduction
  • flexion of 4th & 5th digits

183

radial nn lesion

  • wrist drop
  • loss of sensation in posterior arm & forearm
  • loss of sensation in dorsolateral hand & dorsal thumb

184

lack of CD18

leukocyte adhesion deficiency

185

what kind of proteins are integrins?

ECM proteins

186

ubiquitin-proteasome role in immune response

degrade foreign intracellular particles (viruses) → particles then coupled to MHCI in ER and presented to CD8 cells

187

most common site of thrombus formation in Afib

Left atrial appendage (small sac-like structure)

188

Hartnup disease

defective intestinal & renal absorption of tryptophan

  • decreased nicotinic acid, serotonin, melatonin
  • aminoaciduria of neutral AAs
  • niacin def symptoms: ataxia, diarrhea, dermatitis

189

Vit B6 deficiency symptoms

  • anemia
  • peripheral neuropathy
  • dermatitis

190

niacin precursor AA

tryptophan

191

MOA of inactivated flu vaccine

induces neutralizing Ab's against hemagglutinin → prevents virus from entering cells

192

lipohyalinosis

leakage of plasma proteins thru damaged endothelium →

  • hyaline thickening of vascular wall
  • collagenous sclerosis
  • accumulation of mural foamy macrophages

193

ovarian torsion affects which ligament?

infundibulopelvic (suspensory)

194

cystic degeneration of putamen

Wilson's disease

195

major structure passing thru greater sciatic foramen

piriformis mm

196

pinealoma symptoms

  • obstructive hydrocephalus
  • dorsal midbrain / Parinaud Synd

197

Parinaud Syndrome

Dorsal midbrain compression

  • Upward gaze paralysis
  • Ptosis
  • Pupillary abnormalities

198

surgical landmark for appendectomy

teniae coli

199

Structures passing thru jugular foramen

CN 9, 10, 11

200

Structures passing thru hypoglossal canal

CN 12

201

Structures passing thru foramen magnum

  • Spinal roots of CN 11
  • brainstem aa
  • vertebral aa

202

Structures passing thru internal acoustic meatus

CN 7, 8

203

Structures passing thru foramen spinosum

middle meningeal aa & vv

204

Structures passing thru foramen ovale

CN V3

205

Structures passing thru foramen rotundum

CN V2

206

Structures passing thru superior orbital fissure

  • CN 3, 4, V1, 6
  • Ophthalmic vv
  • Sympathetic fibers

207

Structures passing thru optic canal

  • CN 2
  • Ophthalmic aa
  • Central retinal vv

208

Structures passing thru cribiform plate

CN 1 olfactory bundles

209

unilateral face & arm swelling + unilateral engorgement of subcutaneous vv on neck

brachiocephalic vv obstruction

210

common location of compression/injury to common peroneal nn

fibular neck

211

elastin rubber-like properties due to?

extensive cross-linking btwn elastin monomers, facilitated by lysyl oxidase

212

branches of splenic aa

  • pancreatic
  • short gastric
  • left gastroepiploic

213

tissue vulnerable to ischemic injury w/splenic aa compression?

superior greater curvature of stomach → short gastric aa supply

214

prokaryotic DNA enzyme with 5' to 3' exonuclease activity

DNA polymerase I → removes RNA primer and repairs damaged DNA

215

renal ammoniagenesis

  • stimulated by acidosis
  • renal epithelial cells metabolize glutamine to glutamate → generates NH4 and HCO3
    • HCO3 reabsorbed → buffers acids in blood
    • NH4 excreted → increased renal acid excretion

216

failure to acidify lysosomes would result in what deficiency in the immune response?

deficient MHC II expression → lack of interaction w/T cells

217

what substance is responsible for the synchronization of glycogenolysis with skeletal mm contraction?

Ca2+ → activation of phosphorylase kinase → stimulation of glycogen phosphorylase → glycogenolysis

218

hyperammonemia + increased urinary orotic acid

ornithine transcarbamylase deficiency

219

orotic acid buildup + megaloblastic anemia + delayed growth

uridine monophosphate synthetase deficiency

220

polycistronic mRNA

codes for more than one protein → most prokaryotic mRNAs

221

lac operon

  • codes for proteins necessary for E. coli lactose metabolism
  • lactose binds repressor, preventing it from binding operator → lactose-digesting enzymes translated
  • regulated by single promoter, operator, and set of regulatory elements

222

what does tRNA have on 3' end?

CCA tail → AA binding site

223

tRNA D loop function

facilitates correct tRNA recognition by proper aminoacyl tRNA synthetase

224

tRNA T loop function

contains TWC sequence necessary for tRNA binding to ribosomes

225

medial foot lesions cause LAD where?

inguinal LAD

226

lateral foot lesions cause LAD where?

popliteal & inguinal LAD

227

repetitive forearm pronation/supination can injure what nerve at what location?

radial nn @ supinator canal

  • weakness on finger & thumb extension
  • no wrist drop
  • no sensory deficits

228

incision of what structure can provide relief in carpal tunnel syndrome?

transverse carpal ligament

229

CN 9 lesion symptoms

  • loss of gag reflex
  • loss of general sensation in
    • upper pharynx
    • posterior tongue
    • tonsils
    • middle ear cavity
  • loss of taste on posterior 1/3 tongue

230

structures running thru hepatoduodenal ligament

Portal triad

  1. Hepatic aa
  2. Portal vv
  3. Common bile duct

231

Hepatic bleeding that persists after occlusion of hepatoduodena ligament

IVC or Hepatic vv injury

232

coronary dominance determined by?

coronary aa supplying posterior descending aa

  • R Coronary aa: 70% (right dominant)
  • L Circumflex aa: 10% (left dominant)
  • R Coronary + L Circumflex aa: 20% (codominant)

233

symptoms of ulnar nn injury @ elbow

  • loss of sensation in medial 1.5 digits
  • weakness of wrist flexion
  • weakness of wrist aDduction
  • weakness of finger aB/aDuction
  • weakness of flexion of 4th/5th digits
  • "ulnar claw"

234

retroperitoneal organs

  1. Adrenal glands
  2. Aorta
  3. IVC
  4. Duodenum (except 1st part)
  5. Pancreas (head & body)
  6. Ureters & Bladder
  7. Colon (ascending & descending)
  8. Kidneys
  9. Esophagus
  10. Rectum (mid-distal)

235

defect in direct inguinal hernia

breakdown/weakness of transversalis fascia

236

ureters in females lie anterior, posterior, and medial to which structures?

  • anterior to Internal Iliac aa
  • posterior to Uterian aa
  • medial to Ovarian vessels (within true pelvis)

237

internal carotid aa aneurysm can affect what structure and cause what defect?

lateral aspect of optic chiasm → ipsilateral nasal hemianopia

238

symptoms of CN 11 lesion

  • shoulder droop
  • impaired arm aBduction above horizontal
  • winging of scapula
  • possibly SCM weakness

239

CN 11 innervates which mm?

  • trapezius
  • SCM

240

chemoreceptor trigger zone

  • acute nausea following systemic chemotherapy
  • located in area postrema of dorsal medulla (near 4th ventricle)

241

RA pt intubated, then develops arfelxic paralysis

vertebral subluxation, usually @ atlantoaxial joint

  • severe chronic RA can involve cervical spine
  • laxity/destruction of transverse ligaments OR progressive erosion of odontoid process → increase atlas anterior movement → SC compression

242

atlantoaxial instability w/subluxation symptoms

  • neck pain
  • neck stiffness
  • neurological findings
    • radicular pain
    • areflexic paralysis
    • loss of SNS tone → hypOtension

243

most important mm in performing Valsalva manuever

rectus abdominis

244

location of SA node

junction of R atrium and SVC

245

location of AV node

R atrium near septal cusp of tricuspid valve & orifice of coronary sinus

246

supracondylar humerus fracture w/anterolateral dsiplacement of proximal fracture fragment

radial nn injury → wrist drop + sensory loss over posterior forearm and dorsolateral hand

247

supracondylar humerus fracture w/anteromedial displacement of fracture fragment

median nn & brachial aa injury → sensory loss over 1st 3 digits + weakness of flexion of 1st 3 digits + weakness of wrist flexion + pulseless hand

248

optic tract lesions causes what VF defect?

contralateral homonymous hemianopia + relative pupillary light reflex defect (swinging flashlight test)

249

frontal eye field lesion causes what VF defect?

eyes deviate toward lesion (contralateral field predominates)

250

lateral geniculate nucleus lesion causes what VF defect?

contralateral homonomous hemianopia w/normal pupillary light reflexes

251

optic radiation lesion causes what VF defect?

contralateral homonomous hemianopia w/normal pupillary light reflex

252

Meyer's Loop lesion causes what VF defect?

contralateral upper quadrantanopia

253

Visual cortex lesion causes what VF defect?

contralateral homonomous hemianopia w/macular sparing

254

Thoracic outlet syndrome

Occurs in scalene triangle: anterior scalene mm + middle scalene mm + 1st rib

  • compression of lower trunk of brachial plexus → upper extremity numbness, tingling, weakness
  • compression of subclavian vv → upper extremity swelling
  • compression of subclavian aa → exertional arm pain

255

hemiballism

wild, involuntary, large-amplitude, flinging movements of proximal limbs or on 1 side of body

  • damage to subthalamic nucleus → decreased excitation of globus pallidus → decreased inhibition of thalamus
  • often in setting of lacunar stroke

256

257

femoral nn lesion symptoms

  • quadriceps weakness
  • loss of patellar reflex
  • loss of sensation over anterior/medial thigh and medial leg

258

femoral hernia location

  • inferior to inguinal ligament
  • lateral to pubic tubercle
  • medial to femoral vv

259

internal capsule stroke symptoms

  • pure motor weakness affecting contralateral arm, leg, and lower face
  • contralateral spasticity
  • hyperreflexia
  • positive Babinski

260

MOA of appendicitis pain

  • afferent pain fibers entering at T10 → dull visceral pain at umbilicus
  • progressive inflammation → irritation of parietal peritoneum + abd wall → more severe  somatic pain shifting from umbilicus to McBurney

261

ARDS Mechanism

  • Injury + inflamm of alveolar pneumocytes + pulm epithelium
  • Neutrophil recruitment
  • Inflamm mediator release → more tissue damage
  • Inc pulm capillary permeability → fluid into alveoli
  • Dec surfactant prod → alveolar collapse
  • Inspissation of protein-rich fluid + necrotic debris → hyaline membrane formation

262

focal periosteal elevation of bone

osteosarcoma

263

bone tumor most associated w/Paget disease

osteosarcoma

264

mosaicism

  • mutation during first stages of embryonic development
  • presence of multiple genetically different cell lines w/i body
  • consider when offspring but not parents affected

265

penetrance

  • probabilty that person with mutant genotype will express phenotype
  • highly penetrant = frequently produces clinical signs
  • incomplete penetrance = only sometimes produces clinical signs

266

pleiotropy

single genetic defect causes multiple, seemingly unrelated phenotypic manifestations

267

somatic mutation

  • acquired alteration of somatic cell lineage
  • cannot be passed on to offspring

268

APL translocation

15;17

269

structure at highest risk w/knee joint anterior/posterior dislocation

popliteal aa

rigidly fixed both proximally (adductor magnus) and distally (soleus) to the joint

270

structure at highest risk w/blunt trauma to lateral knee

common peroneal nn

271

sublimation

mature: channeling unacceptable impulses into more socially acceptable ones

272

displacement

feelings associated w/one situation or person are inappropriately shifted to another

273

acting out

immature: express feelings/impluses through actions

274

projection

attribute own unacceptable thoughts/feelings to another person

275

reaction formation

intense unacceptable feelings transformed into opposites

276

reflection

facilitating interview technique in which physician repeats what the pt has said

277

4 facilitative interview techniques

  1. reflecting on what pt just said
  2. summarizing conversation
  3. open-ended questions
  4. supportive, empathetic statements

278

4 obstructing interview techniques

  1. closed-ended or yes/no questions
  2. minimizing pt concerns
  3. judging pt, offering premature advice
  4. confronting pt in hostile manner

279

location of action of PDE5 inhibitors

corpora cavernosa smooth mm cells

280

Relative Risk

RR = Risk in exposed subjects / Risk in unexposed subjects

281

Number Needed to Treat

NNT = 1/ARR

(ARR = event rate in test group - event rate in control group)

282

acute intermittent porphyria enzyme deficiency

AD defect in porphobilinogen deaminase (converts porphobilinogen → hydroxymethylbilane)

283

porphobilinogen deaminase deficiency

acute intermittent porphyria

284

uroporphyrinogen decarboxylase deficiency

porphyria cutanea tarda

285

porphyria cutanea tarda enzyme deficiency

uroporphyrinogen decarboxylase (converts uroporphyrinogen II → coproporphyrinogen III)

286

uroporphyrinogen III synthase deficiency

congenital erythropoietic prophyria

287

coproporphyrinogen III oxidase deficiency

hereditary coproporphyria

288

protoporphyrinogen oxidase deficiency

variegate porphyria

289

characteristics of pleural fluid in CHF

  • low LDH content
  • low protein content (transudate)

290

characteristics of infxn-driven pleural effusion

  • high protein content (exudate)

291

Rb gene location

Chrom 13

292

DiGeorge cardiac defects

conotruncal abnormalities (TOF, truncus arteriosus)

293

6 metabolic disturbances in DKA

  1. Metabolic Acidosis
  2. Ketonemia
  3. Hyperglycemia
  4. Hyperkalemia
  5. HypOnatremia
  6. Hyperammonemmia (mm degradation)

294

46,XY pt w/female phenotype, blind vagina, inguinal testes

XL Androgen insensitivity

295

46,XX pt w/blind vagina, normal ovaries

Mullerian agenesis (Mayer-Rokitansky-Kuster-Hauser Synd)

296

46,XX pt w/abnormal vagina, normal uterus & ovaries

Malformation of urogenital sinus & Mullerian ducts → transverse vaginal septum

297

45,XO patient

Turner Synd

298

germinal matrix

  • dense cellular & vascular layer of subependymal zone from which neurons & glial cells develop
  • begins to involute at 28wks gestation
  • weak vascular network → spontaneous IVH in preemies (lateral, 3rd, & 4th ventricles)

299

Cisplatin toxicity

  • sensory (high-freq) hearing loss
  • nephrotoxicity (prevent w/amifostine)
  • peripheral neuropathy

300

Etoposide toxicity

  • Alopecia
  • GI irritation
  • BM suppression

301

Doxorubicin toxicity

  • Dilated cardiomyopathy (prevent w/dexrazoxane)
  • Alopecia
  • BM suppression

302

Methotrexate toxicity

  • Severe BM suppression (prevent w/lecovorin)
  • Hepatotoxicity (fatty)
  • Mucositis
  • Pulmonary fibrosis

303

Cytarabine toxicity

  • Megaloblastic anemia
  • BM suppression

304

5-FU toxicity

  • BM suppression that worsens w/leucovorin

305

Bleomycin toxicity

  • Pulmonary fibrosis
  • Skin hyperpigmentation

Minimal BM suppression

306

Busulfan toxicity

  • Severe BM suppression
  • Pulm fibrosis
  • Hyperpigmentation

307

Cyclophosphamide toxicity

  • Hemorrhagic cystitis (prevent w/mesna)
  • BM suppression

308

Nitrosurea toxicity

  • CNS effects

309

Vincristine toxicity

  • Neurotoxicity (incl peripheral neuropathy)
  • Constipation (incl paralytic ileus)

310

Irinotecan toxicity

  • Diarrhea
  • Severe BM suppression

311

Palmitoylation

anchors carboxyl tail FAs to plasma memb cysteine residues → inc hydrophobicity of protein

312

Effects of nitrates

  • Systemic venodilation
  • Dec LV volume
  • Dec LV wall stress
  • Dec myocardial O2 demand
  • Reflex tachycardia

313

GNAS1 defect

Albright Hereditary Osteodystrophy (Pseudohypoparathyroidism Type 1a) 

  • Codes for alpha subunit of Gs protein that mediates PTH effects
  • End-organ PTH resistance

314

3 steps of mRNA processing

  1. 5' capping: 7-methylguanosine added via 5'-5' triphosphate linkage → stabilizes mRNA in cytosol
  2. Poly(A) tail add: poly(A) polymerase adds tail rich in adenosine residues → stabilizes 3' end in cytosol
  3. Splicing: snRNPs facilitate removal of introns

315

Allelic heterogeneity

different mutations at same genetic locus cause similar phenotypes

316

Anticipation

increased severity or earlier onset of inherited disease in successive generations (XL trinucleotide repeat diseases)

317

Epistasis

interactions btwn multiple genes that combine to create a new phenotype or mask/modify the phenotype of one of the genes

ex: pt w/SCD also has mutation causing inc HbF → milder clinical course

318

expressivity

variations in phenotypic severity btwn individuals with the same gene mutation

319

Menkes disease

  • Dec serum copper content
  • Abnormally pigmented, kinky hair
  • HypOpigmented irises

320

cirrhosis can cause increased pressure in which vessels?

  • Splenic vv → splenomegaly
  • Esophageal vv → varices

321

bacterial antibiotic efflux pumps

  • requires energy
  • move protons along gradient + simultaneous expulsion of antibiotic against gradient → out of cell

322

rhizomelia

shortened proximal extremities

323

Achondroplasia features

  • Rhizomelia
  • Brachydactyly in trident config
  • Macrocephaly
  • Midface hypoplasia
  • Frontal bossing
  • Inc risk spinal stenosis

324

COL1A1 gene mutation

Osteogenesis imperfecta

325

FMR1 gene mutation

Fragile X

326

N-terminal peptide signal sequences

  • 15-20 hydrophobic AA residues
  • Indicate proteins destined for RER
  • Removal/dysfcn → inappropriate accumulation in cytosol

327

branched-chain alpha-keto acid accumulation in blood and urine

Maple Syrup Urine Disease

  • defect in branched-chain alpha-keto acid dehydrogenase complex + Vit B1
  • inability to degrade branched-chain AAs (Leu, Ile Val)\
  • CNS toxicity + sweet-smelling urine

328

what is required to maintain high local concentrations of testosterone for sperm prod/maturation?

ABP made by Sertoli cells (makes testosterone & DHT less lipophilic, reducing diffusion out of luminal fluid)

329

Glucagon receptor type

Gs

330

Insulin receptor type

Receptor tyrosine kinase (PI3 kinase)

331

Rx axillary hyperhidrosis

  • Systemic anticholinergics
  • Local anticholinergic injectables
  • Surgical sympathextomy at T2 symp trunk

332

Red safranin O stain

looks for cartilage, mast cell granules, mucin

333

gubernaculum becomes what in females?

  • inferior: round ligament of uterus → passes thru inguinal canal and attaches to labia majora
  • superior: proper ovarian ligament → connects ovary to uterus

334

metabolic disturbances in PE

V/Q mismatch → hypoxemia → hyperventilation

  • Respiratory alkalosis (inc pH)
  • Dec PaCO2
  • Dec PaO2

335

Red Man Syndrome

  • Rapid Vancomycin infusion
  • Widespread release of histamine from mast cells
  • Severe pruritis + rash

336

idiopathic pulmonary arterial HTN

Inc pulm aa pressure + RV failure

  • Pulm endothelial injury
  • Narrowing of pulm vascular bed → RVH
  • Accelerated vascular injury + Inc RV afterload
  • RV dilation

337

right ventricular heave

suggests RVH

338

pelvic heaviness + heavy menstrual bleeding in premenopausal pt

Leiomyomas

339

Why do fibroids cause heavy menstrual bleeding?

biochemical vasoactive growth factor expression → venous ectasia

340

Acyl-CoA dehydrogenase deficiency

  • Most common genetic defect in FA B-oxidation
  • Hypoketotic hypoglycemia after prolonged fasting

341

Acetyl-CoA carboxylase

  • Catalyzes 1st step in FA synthesis
  • Major site of regulation of FA synthesis
  • Naturally inhibited during fasting

342

Glucose-6-Phosphatase

  • Dephosphorylates glucose-6P to free glucose
  • Free glucose released into circulation during glycogenolysis and gluconeogenesis
  • Deficiency: Von Gierke disease → fasting hypoglycemia + glycogen accum in liver/kidneys

343

Glycogen phosphorylase

  • Cleaves alpha-1,4 glycosidic linkage btwn glucose residues in glycogen
  • Liberates glucose-1P
  • Deficiency: McArdle → exercise intolerance + mm pain

344

Increase in enzyme concentration does what to Vmax and Km?

Increases Vmax, no change to Km

345

Carcinoid tumors can cause what vitamin deficiency?

Depletion of Trp stores by tumor as it produces excess 5-HT → Niacin deficiency → pellagra-like symptoms

346

initiation of eukaryotic translation

small ribosomal subunit binds 5' cap of mRNA, facilitated by eIFs, and scans for methionine start codon (AUG) within Kozak consensus sequence [(gcc)gccRccAUGG]

347

Shine-Dalgarno sequence

 

  • AGGAGG
  • facilitates translation initiation in prokaryotes

348

Internal ribosome entry

  • Caspase activation disrupts eIFs → alternative translation method for apoptosis protein synth
  • Internal ribosome entry site (IRES) attracts ribosome to mRNA and allows translation to being in the middle of the mRNA sequence
  • IRES usually located in 5' untranslated region (directly upstream from translation start codon)

349

Thiazolidinediones

  • PPAR-y agonists
  • Decrease insulin resistance by upregulating genes for:
    • GLUT4: increases adipocyte + skeletal mm glucose uptake
    • Adiponectin: increases # insulin-responsive adipocytes + stimulates FA oxidation

350

Rx hepatic encephalopathy

  • Lactulose: acidifies GI tract, aiding conversion of NH3 to NH4+ and trapping NH4+ for excretion
  • Rifaximin: decreases colonic ammoniagenic bacteria
  • Benzoate, Phenylacetate, Phenylbutyrate: bind to NH4+ and increase excretion

351

recurrent laryngeal nn innervates what mm?

  • all intrinsic larynx mm responsible for sound production EXCEPT cricothyroid

352

dsRNA virus

Reovirus

353

ssDNA virus

Parvovirus

354

DNA virus that replicates in cytoplasm

Poxvirus

355

RNA virus that replicates in nucleus

Influenza

356

RPF equation

RPF = MAP / TVR

TVR = afferent arteriole resistance + efferent arteriole resistance

357

Efferent arteriole constriction effect on GFR & RPF

  • Inc GFR
  • Dec RPF

358

Afferent arteriole dilation effect on GFR & RPF

  • Inc GFR
  • Inc RPF

359

Efferent arteriole dilation effect on GFR & RPF

  • Dec GFR
  • Inc RPF

360

Afferent arteriole constriction effect on GFR & RPF

  • Dec GFR
  • Dec RPF

361

Afferent and efferent arteriole dilation effect on GFR & RPF

  • Dec GFR
  • Inc RPF

362

unmyelinated neurons

  • autonomic postganglionic nerves
  • afferent neurons that conduct heat sensation
  • afferent neurons that transmit slow-onset dull, burning, or visceral pain
  • 1st order bipolar sensory neurons of olfaction

363

standard error

measure of variability about the mean

SE = std dev / square root of sample size

364

part of kidney most vulnerable to ischemia

outer medullary regions → relatively low blood flow and high metabolic activity of tubular segments (straight PCT, TALH)

365

Praeder-Willi caused by?

Chrom 15 Paternal deletion

366

Angelman Synd caused by?

Chrom 15 Maternal deletion

367

elevated hormones in PCOS

  • LH
  • Testosterone
  • Insulin

368

HGPRT defect

Lesch-Nyhan Synd

369

Lesch-Nyhan Synd

  • XLR defect in HGPRT
  • Dec purine salvage, inc purine synth, hyperuricemia/uria
  • Self-mutilating behavior
  • Mild intellectual disability
  • Involuntary movements
  • Delayed motor development
  • Nephrolithiasis
  • Gout

370

Cellular differentiation determined by?

transcription factors

371

what can induce cellular dedifferentiation?

transcription factors

372

pernicious anemia effects

  • chronic atrophic gastritis
  • hypOchlorhydria → increase in gastrin secretion
  • parietal cell loss → no IF → B12 deficiency

373

HOXA13 mutation

Hand-Foot-Genital Syndrome

  • malformations of distal limbs
  • Mullerian fusion abnormalities

374

HOX genes

encode transcription factors that guide embryo development along rostro-caudal, limb, and genital axes

375

PAX genes

important for embryologic specification of certain tissues (eye, brain)

376

Vitamin D effects

  • Inc intestinal and renal absorption of Ca & PO4
  • Dec PTH secretion
  • Inc bone mineralization

377

Causes of anion gap metabolic alkalosis

  • Methanol
  • Uremia
  • DKA
  • Propylene glycol
  • INH / Iron
  • Lactic acidosis
  • Ethylene glycol
  • Salicylates / Starvation

378

Steps in thermal cycling PCR

  1. Heating: DNA denaturation
  2. Cooling: primer hybridization
  3. Rewarming: primer extension + DNA synthesis

379

opening to maxillary sinus?

middle nasal meatus

380

visual defect in MCA infarct?

homonymous hemianopsia

381

Posterior cervical LN

  • Scalp & neck
  • Skin of arms & pectorals
  • Thorax
  • Cervical & axillary nodes

382

Postauricular LN

  • External auditory meatus
  • Pinna
  • Scalp

383

Preauricular LN

  • Eyelids & conjunctivae
  • Temporal region
  • Pinna

384

Right supraclavicular LN

  • Mediastinum
  • Lungs
  • Esophagus

385

Left supraclavicular LN

Virchow's node

  • Via thoracic duct:
    • Thorax
    • Abdomen

386

Virchow's node enlargement

Left supraclavicular node → occult abdominal malignancy

387

I band

  • contains Z line and thin actin filaments
  • mm relaxation: lengthens
  • mm contraction: shortens

388

A band

  • sarcomere thick filaments
  • always remains same length

389

M line

  • center of A band
  • thick filaments anchor to structural elements in center of sarcomere

390

H band

  • contains thick filaments that do not overlap with thin filaments
  • mm relaxation: lengthen
  • mm contraction: shorten

391

portal HTN effect on spleen

  • inc pressure in splenic vv
  • splenomegaly
  • red pulp expansion (blood congestion)

392

interscalene nerve block

  • anesthesia for shoulder & upper arm
  • affects brachial plexus roots & trunks
  • transient ipsilateral diaphragmatic paralysis (phrenic nn, C3-5)

393

what is unique about the daughter DNA strand synthesized in opposite direction of replication fork?

Okazaki fragments → synthesis of multiple short fragments still in 5' to 3' direction (needs many RNA primers)

394

Nitrate MOA

  • Vasc smooth mm cells metabolize to NO
  • NO activates guanylate cyclase → increases cGMP
  • Dec intracellular Ca2+ → dec myosin LC kinase activity → myosin LC dephosphorylation
  • Smooth mm relaxation

395

Myosin light chain kinase function

Myosin light chain phosphorylation → smooth mm contraction

396

Protein primary structure

AAs linked by covalent peptide bonds

397

Protein secondary structure

Hydrogen bonds → alpha helix or beta sheet

398

Protein tertiary structure

Ionic bonds + hydrophobic interactions + hydrogen bonds + disulfide bonds → folding

399

disulfide bonds

very strong covalent bonds btwn 2 cysteine residues w/i same polypeptide chain that enhance protein ability to withstand denaturation

400

AV shunt effect on cardiac function

  • Inc preload
  • Dec afterload
  • High-output failure

401

what vessel limits ascent of horseshoe kidney

inferior mesenteric aa

402

test to compare means of 2 groups

T-test

403

test to compare means of 3+ groups

ANOVA

404

test to compare 2+ percentages or proportions of categorical outcomes

Chi-Square

405

which cells synthesize fibrous cap of mature atheroma?

vascular smooth mm cells (collagen + ECM)

406

Neural Crest derivatives

MAGIC COPS (see DIT)

or

MOTEL PASS

  • Melanocytes
  • Odontoblasts/Ossicles
  • Thyroid cartilage
  • Enterochromaffin cells
  • Laryngeal cartilage
  • Parafollicular cells
  • Adrenal medulla + ganglia
  • Schwann cells
  • Spiral membrane

407

dense pigments made of EPI metabolites in hepatic lysosomes + intermittent jaundice

Dubin-Johnson Synd → defective hepatic excretion of bilirubin glucuronides across canalicular memb (inc direct bilirubin)

408

Acyclovir MOA

  • Monophosphorylation by viral thymidine kinase (rate-limiting) → activation
  • Most effective against HSV, VZV

409

viruses that acquire envelopes via budding from nuclear membrane

Herpesviridae (incl EBV, CMV)

410

Virus w/partially double-stranded circular DNA + RNA-dependent DNA polymerase

Hep B

411

Entacapone MOA

  • COMT inhibitor
  • Dec peripheral metabolism of levodopa

412

tumor w/non-membrane-bound clear cytoplasmic vacuoles and nuclear membrane scalloping

liposarcoma

413

DNA Helicase

unwinds double helix

414

DNA gyrase

removes supercoils

415

DNA Topoisomerase II

removes supercoils

416

Single-stranded DNA binding protein

stabilizes unwound template strands

417

Primase

Synthesizes RNA primer

418

RNA polymerase

Synthesizes RNA primer

419

DNA Polymerase III

  • 5' → 3' DNA synthesis
  • 3' → 5' exonuclease activity

420

DNA polymerase I

  • 5' → 3' DNA synthesis
  • 3' → 5' exonuclease activity
  • 5' → 3' exonuclease activity: removes RNA primer and replaces w/DNA

421

DNA ligase

Joins Okazaki fragments (lagging strand)

422

Receiver operating characteristic curve

  • Plots sensitivity against 1-specificity
  • Area under curve = test accuracy

423

Tamm-Horsfall glycoprotein

  • Secreted by renal tubular epithelial cells in ascending LOH
  • May accumulate to form hyaline casts in pts w/prerenal azotemia + low urine flow rate

424

Foam stability index

  • evaluates surfactant functionality
  • EtOH + amniotic fluid → look for highest-value well w/ring of stable foam

425

Slide agglutination test for phosphatidylglycerol

tests for surfactant functionality

426

427

Inferior ectopia lentis

Homocystinuria (cystathione beta-synthase deficiency)

428

Superior ectopia lentis

Marfan

429

cross placenta: water-soluble or lipid-soluble?

lipid-soluble

430

genetic reassortment

  • 2 distinct influenza A viruses (human + animal) infect same cell → HA from one and NA from other packaged into new virion
  • aka Antigenic Shift
  • responsible for Pandemics

431

Parinaud Syndrome

  • Upward gaze palsy
  • Pinealoma

432

bowel epithelial stem cells located where?

Crypts of Lieberkuhn

433

CAAT box

  • transcription promoter
  • binding site for TFs and RNA Pol II
  • same fcn as TATA box

434

lysyl hydroxylase

  • adds hydroxyl groups to lysine and proline in procollagen
  • Vit C cofactor

435

spherical nodules separated by bridging fibrous septae in liver

cirrhosis (regenerating hepatocytes)

436

Stellate cells

  • liver
  • store Vit A
  • support sinusoids
  • can differentiate into myofibroblast w/liver injury
  • large role in production of fibrosis in cirrhosis

437

cystic hygroma

  • cystic lymphatic malformation
  • loose areolar tissue of head and neck
  • more often left-sided
  • painless, compressible mass that transilluminates
  • assoc w/Turner and trisomies 13, 18, 21

438

cause of lactose intolerance later in life

normal downregulation of lactase gene expression by small intestine enterocytes

439

lung volumes increased in COPD pt?

  • Residual volume
  • Functional residual capacity
  • Total lung capacity

440

cells in petri dish pile up into mounds

malignant cells → no contact inhibition

441

contact inhibition

  • normal cells
  • reproduce until petri dish surface covered w/single layer
  • cadherin + catenin-mediated halt in mitosis when they touch each other

442

what happens to GFR and FF with decreased renal perfusion pressure?

  • Inc GFR (efferent aa constriction)
  • Inc FF (GFR/RPF)

443

Orlistat

  • Intestinal lipase inhibitor
  • Decreases intestinal fat absorption
  • Produces modest weight loss
  • Significant GI side effects

444

Jones methanamine silver stain in kidney

can show GBM thickening (capillary walls) of membranous glomerulonephritis

445

venous drainage of rectum superior to pectinate line

sup rectal vv → inf mesenteric vv → portal system

446

venous drainage of rectum inferior to pectinate line

middle & inf rectal vv → internal iliac vv → systemic circulation

447

insulin increases concentrations of which pro-glycolytic substance?

PFK2 → Fructose 2,6-bisphosphate → promotes PFK1 activity

448

Hydrophobic AAs

  1. Alanine
  2. Valine
  3. Leucine
  4. Isoleucine
  5. Phenylalanine
  6. Tryptophan
  7. Methionine
  8. Proline
  9. Glycine

449

What mediates larger increase in insulin release for oral glucose (vs IV)?

GLP-1 → incretin produced by gut mucosa

450

ApoB-48

  • Truncated form of Apo-B100 (premature stop codon)
  • Produced by intestinal enterocytes
  • Incorporated into chylomicrons

451

syncope most often caused by?

decrease in cerebral blood flow

452

cough syncope

  • overweight male pts w/COPD
  • increased intrathoracic pressure → decreased venous return to heart → transient decrease in CO + cerebral perfusion
  • same mechanism as Valsalva

453

micturition syncope

  • during rising at night from sleep to urinate
  • peripheral blood pooling → orthostatic hypOtension

454

carotid sinus-related syncope

carotid sinus stimulation → increased vagal tone → bradycardia

455

Vertebrobasilar insufficiency

  • syncope
  • vertigo
  • visual field defect
  • diplopia
  • hearing loss
  • facial numbness
  • dysphagia
  • dysarthria
  • nystagmus
  • ataxia
  • contralateral P/T defects

456

hyperestrogenemia in cirrhosis

  • decreased metabolism in liver + decreased sex hormone-binding globulin + decreased androgen metabolism
  • spider angiomas
  • palmar erythema
  • gynecoamstia
  • testicular atrophy
  • decreased body hair
  • Dupuytren's contractures

457

hypERammonemia

  • Hepatic encephalopathy
  • Disturbed sleep
  • Asterixis
  • HypERactive DTRs
  • Transient decerbrate posturing

458

Neurofibromas

loose, disorganized proliferations of Schwann cells, fibroblasts, and neurites

459

Latex agglutination test

  • absence of agglutination → positive result
  • agglutination → negative result

460

why is paclitaxel in drug-eleuting stents?

inhibit cell division → inhibit intimal hyperplasia → decrease stent thrombosis

461

ornithine transcarbamoylase deficiency

  • Most common urea cycle defect
  • Accumulation of carbamoyl phosphate → orotic acid
  • Congenital hypERammonemia

462

Intracellular steps in collagen synthesis

  • Preprocollagen into ER
  • Cleaved into procollagen
  • Vit-C dependent hydroxylation of proline + lysine by prolyl hydroxylase + lysyl hydroxylase
  • Glycosylation of select hydroxylysines
  • Triple helix formation

463

Extracellular steps in collagen synthesis

  • Terminal propeptides cleaved by procollagen peptidases → Tropocollagen
  • Collagen fibrils spontaneously assemble
  • Lysyl oxidase forms covalent cross-links

464

hypOkalemia symptoms

  • mm weakness
  • cramps
  • myalgias
  • fatigue
  • respiratory depression
  • ventricular arrhythmias

may be caused by loop diuretics

465

IVC obstruction

can be seen in renal tumors due to intraluminal spread and thrombus formation

  • bilateral lower extremity edema
  • prominently visible abd wall collateral venous circulation

466

fibroadenoma vs fibrocystic change

Fibroadenoma:

  • solitary round mass
  • firm w/clear borders
  • nontender
  • mobile
  • proliferation of stromal + ductal elements surr by fibrous capsule
  • estrogen-sensitive

Fibrocystic change:

  • solitary mobile cyst OR multiple diffuse nodulocystic masses
  • cyclic premenstrual tenderness
  • flattened epithelial/apocrine metaplasia surrounding blue/brown fluid
  • compressed fibrous stroma

467

CDKN2A gene mutations

  • encodes cyclin-dependent kinase inhibitor 2A (negative regulator at G1 → S that binds/inhibits CDK4)
  • mutation → inappropriate cell cycle progression
  • Dysplastic Nevus Synd (inc risk melanoma)

468

CDKN2A gene location

9p21

469

Prosencephalon

  • Telencephalon → Cerebral hemispheres + lateral ventricles
  • Diencephalon → Thalamus + 3rd ventricle

470

Mesencephalon

midbrain + aqueduct

471

Rhombencephalon

  • Metencephalon → Pons + Cerebellum + Upper 4th Ventricle
  • Myelencephalon → Medulla + Lower 4th Ventricle

472

Leucine Zipper

  • Eukaryotic transcription factor
  • 2 alpha-helical proteins that combine to form a dimer
  • Each dimer has:
    • DNA-binding region made of basic AAs → bind in major groove of DNA
    • LZ dimerization domain containing repeated leucine residues every 7th position → hydrophobic interaxns

473

Carbamoyl phosphate synthetase II

  • Catalyzes initial step in de novo pyrimidine synth
  • Located in cytosol
  • CO2 + 2ATP → carbamoyl phosphate

474

Carbamoyl phosphate synthetase I

  • First step in urea cycle
  • Located in mitochondria
  • CO2 + 2ATP → carbamoyl phosphate

475

Iliopsoas test

  • Flex hip against resistance
  • Tests for inflammation of psoas mm or overlying parietal peritoneum
  • Common causes of positive result (pain):
    • Appendicitis
    • Psoas abscess

476

Structures traversing diaphragm

  • T8: IVC
  • T10: Esophagus + Vagal Trunks
  • T12: Aorta + Azygous Vein + Thoracic Duct

477

Glucokinase

  • Preferentially expressed in pancreatic beta-cells
  • Regulatory role in insulin secretion
    • Glucose → Glucose-6P → ATP → K+ channel closure → Ca2+ influx → insulin release
  • Also role in regulation of glycogen synth in liver
  • Mutation → increased glucose threshold necessary for insulin release

478

Maturity-onset diabetees of the young

  • AD group of d/o
  • Mutations in glucokinase gene or associated TFs
  • Impaired insulin secretion w/minimal or no defects in insulin action
  • Non-insulin-dependent diabetes in lean young adults
  • Mild hyperglycemia that usually doesn't require medication

479

von Gierke disease

  • Glucose 6-phosphatase deficiency
  • Hepatomegaly
  • Lactic acidosis
  • Fasting hypOglycemia that does not improve w/fructose or galactose administration

480

Pompe disease

  • Lysosomal acid alpha-glucosidase / acid maltase deficiency
  • Cardiomegaly in infancy
  • Hypertrophic cardimyopathy
  • Diffuse mm weakness
  • Macroglossia

481

Lab findings in DIC

  • Dec fibrinogen (consumption)
  • Inc fibrin degradation products (clot lysis)
  • Inc PT / PTT
  • Thrombocytopenia
  • Schisotcytes (sometimes)

482

Vasogenic edema

  • Disruption of BBB → inc vasc permeability → inc plasma filtration into cerebral interstitium → inc ICP + midline shift
  • Can be caused by intracerebral neoplasm

483

anti-HBc IgG

indicates previous HBV infxn

484

how can hypercalcemia cause nephrogenic DI?

downregulation of aquaporins → inhibition of H2O reabsorption and urine concentration

485

GpIIb/IIIa receptor type

Integrin receptor

486

mechanism of liver injury in HBV infxn

CD8+ T cells destroy infected hepatocytes

487

Connexins

Gap junctions

Coordinate contractions, increase excitability

UW11888

488

aortic arches

UW1750

489

oocyte arrested in which phase until puberty?

Prophase I

490

oocyte arrested in which phase from ovulation to fertilization?

Metaphase II

491

MTHFR deficiency

most common cause of hyperhomocysteinemia → failure to convert to methionine

UW788

492

collagen translation and post-translational processing occur where?

RER

493

collagen proteolytic processing and cross-linking occur where?

extracellular space

494

BUN in liver disease

decreased

ammonia not converted to urea → hyperammonemia