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Flashcards in UWorld_2.24 Deck (25)
1

Epithelial structure @ respiratory tract

  • stratified squamous epithelium
    • oropharynx
    • laryngopharynx
    • anterior epiglottis
    • upper half of post. epiglottis
    • vocal folds (true vocal chords)
  • pseudostratified, columnar (mucous-secreting) epithelium
    • nose
    • paranasal sinus
    • nasopharynx
    • larynx
    • tracheobronchial tree

2

Tendons of rotator cuff + injuries

  • Rotater cuff stabilizes glenohumoral joint w/ligaments of GH joint and biceps brachii tendon
  • SITS:
    • Supraspinatus
    • Infraspinatus
    • Teres minor
    • Subscapularis
  • supraspinatus = most common injury
    • most superior muscle ==> 10-15 deg. of arm abduction
    • tested by "empty can test"
    • ==> pain with abduction + flexion

3

Characteristics of the "delta agent"

  • "delta agent" = hepatitis D virus
  • replication-defective RNA virus
  • only capable of causing infection when encapsulate w/HBsAg
  • presentation
    • acute coinfection w/Hep B
    • superinfection of chronic HBV carrier

4

Characteristics of fulminant viral hepatits

  • rare
  • can arise w/any hepatitis virus

5

Impacts of efferent arteriole constriction

  • efferent arteriole constriction ==> increase hydrostatic pressure @ capillaries ==> increased GFR
    • GFR starts to fall from max increase after resistance increases > 2x normal
  • efferent arteriole constriction ==> decrease in RBF
  • efferent arteriole constriction ==> increase in FF
    • FF = GFR/RBF

6

Filtration fraction = 

FF = GFR/RBF

7

Langerhans cell characteristics

  • dendritic cells found at skin and mucous membranes
  • myeloid cell line 
    • myeloid stem ==> granulocyte-monocyte progenitor ==> dendritic
  • antigen-presenting cell
    • express MHC Class II + co-stimulatory B7 cell surface molecules
    • interact w/T lymphocytes
  • Birbeck granules = "racquet-shaped" intracytoplasmic granule

8

Isoniazid side effects

  • peripheral neuropathy (if given w/pyroxidine)
  • hepatotoxicity
    • usually mild ==> transient elevated AST, ALT
    • elevated bilirubin
    • fever, anorexia, nauseau
    • severe ==> liver dysfxn, jaundice, bilirubinuria

9

Hib vaccine + importance

  • composed of polyribosyl-ribotol-phosphate (PRP) = component of Hib capsule
  • [conjugated w/diptheria or tetanus toxoid]
  • ==> lasting immunity against Hib in children
  • H. flu ==> epiglottitis 

10

Incomplete obliteration of precessus vaginalis ==>

  • hydrocele = connection between scrotum and abdominal cavity ==> fluid leakage into scrotum
  • indirect inguinal hernia ==> protrusion of abdominal organs along inguinal canal

11

Frameshift mutation

Missense mutation

Nonsense mutation

Conservative mutation

  • frameshift = deletion/insertion ==> change in reading frame
  • missense = substitution @ point ==> different aa
  • nonsens = substitution @ point ==> premature stop codon
  • conservative = missense where aa is similar ==> normal protein length and possible similar secondary structure and fxn

12

PAH handling @ kidney

Inulin handling @ kidney

  • PAH
    • mostly filtered
    • small amount excreted @ proximal
    • no reabsorb
  • inulin
    • some filtration 
    • no excretion or reabsorbtion

13

Sodium handling @ kidney

Glucose handling @ kidney

Urea handling @ kidney

  • Sodium
    • 99% of filtered sodium reabsorbed
  • Glucose
    • complete reabsorption @ low filtered loads
    • increasing fractional excretion of glucose @ higher plasma concentrations
  • Urea
    • 40-50% of filtered urea is reabsorbed
    • @ fixed GFR and euvolemia ==> constant fractional excretion

14

vWD presentation

  • lifelong history of mucosal bleeding, gingival bleeding
  • epistaxis, menorrhagia
  • normal platelet levels
  • prolonged bleeding time due to impaired platelet fxn

15

S1 injury ==>

  • posterior thigh and leg pain
  • weakness of plantar flexion
  • diminished ankle jerk reflex

16

L4 injury ==>

  • impairment of knee-jerk reflex

17

L5 injury ==> 

  • posterior and lateral thigh and leg pain ==> inner foot

18

Sciatic nerve = 

  • L4 - S3 nerve roots
  • sciatica = commonly L5 or S1 injury

19

Raloxifene: MOA

  • SERM
  • estrogen agonist @ bone ==> prevention of osteoporosis
  • estrogen antagonist @ breast ==> prevention of breast cancer

20

Atenolol: MOA + effects

  • B1 receptor antagonist
  • @ cardiac tissue and JGA, but not @ vascular smooth muscle
  • ==> decreased cAMP @ cardiac/renal

21

Presentation/characteristics of McArdle's syndrome

  • myophosphorylase deficiency:
    • muscle glycogen ==> glucose-1-phosphate
  • ==> failure of glycogenolysis
  • ==> exercise intolerance + myoglobinuria + muscle pain w/activity

22

Clinical presentation of organophosphate poisoning

  • Organophosphate poisoning (e.g. pesticides) ==> irreversible inhibition of cholinesterase @ muscarinic & nicotinic cholinergic synapses
  • muscarinic activation ==>
    • Diarrhea; diaphoresis
    • Urination
    • Miosis
    • Bronchospasm
    • Bradycardia
    • Emesis
    • Lacrimation
    • Salivation
  • nicotonic activation ==>
    • muscle fasciculations
    • paralysis
    • seizures
    • CNS dperession

23

Tx of organophosphate poisoning

  • Atropine: reversal of muscarinic sx; no effect on nicotinic receptors
    • pts still at risk for muscle paralysis
  • Pralidoxime: reverses muscarinic and nicotinic effects of organophosphates
    • effective only if given early after the exposure

24

Metabolism of glucose @ RBCs

  • no mitochondria or nucleus
  • metabolism of glucose via glycolysis & HMP (hexose monophosphate) shunt
  • glycolysis ==> energy fr survival
  • HMP shunt ==> NADPH production to prevent ocidant damage
    • G6PD helps produce NADPH

25

Causes of unregulated oxidative damage in RBCs

  • G6PD deficiency ==> no NADPH to prevent from oxidative damage
  • Glutathione reductase deficiency
    • H2O2 ==> water via oxidation of glutathione
    • NADPH is used by glutathione reductase  to reduce oxidized glutathione
    • glutathione can then  be reused to reduce another molecule of hydrogen peroxide 

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