6/8 UWorld

Question 1

What is orthopnea

Answer 1

SOB while lying flat

Question 2

What is the only cardiac abnormality that INCREASES with valsalva maneuver

Answer 2

• Valsalva maneuver
  
  • This increases intrathoracic pressure, thus decreasing preload (opposite of inspiration)
  • Decreases all murmurs except increases S4 heard in hypertrophic cardiomyopathy

Question 3

What is pleiotropy

Answer 3

When one gene mutations contributes to multiple phenotypic effects, often in different organ systems

Question 4

What is effect modification

Answer 4

• When the effect of the main exposure on the outcome is modified by the presence of another variable
  
  • E.g. Experimental drug has a significant effect in non-smokers but insignificant effect in smokers
• Effect modification is not a bias

Question 5

What is relative risk and its equation?

Answer 5

• Probability of getting disease in exposed group vs. probability of getting disease in unexposed
  
  • Calculated from cohort studies
• Equation:
  
  • RR = [a/(a+b)] / [c/(c+d)]

Question 6

What is odds ratio and its equation

Answer 6

• Odds that group with disease (case) was exposed to a risk factor vs. odds that group without disease (control) was exposed
  
  • Calculated from case-control studies
• Equation:
  
  • OR = [(a/c) / (b/d)] = ad/bc

Question 7

Occlusion of what artery will cause Wernicke’s aphasia?

Answer 7

Middle cerebral

Question 8

Occlusion of what artery will cause Broca’s aphasia?

Answer 8

Middle cerebral

Question 9

What dietary substance other than fructose should be avoided in aldolase B deficiency?

Answer 9

Sucrose (disaccharide that breaks down into fructose)

Question 10

In what 3 steps of the citric acid cycle is ribaflavin (B2) necessary?

Answer 10

Pyruvate dehydrogenase (TLCFN)

Alpha-ketoglutarate dehydrogenase (TLCFN)

Succinate dehydrogenase (FAD –> FADH2)

Question 11

What is the sublingual drug given to patients with angina

Answer 11

Nitroglycerin

• Venodilation = decreased preload

Question 12

What are the symptoms of Gerstmann Syndrome

Answer 12

• Aka defect in dominant parietal lobe
• Symptoms:
  
  • Agraphia (inability to write)
  • Acalculia (inability to calculate)
  • Finger agnosia (inability to identify individual fingers)
  • Left-right disorientation

Question 13

What is the MOA of phenelzine

Answer 13

Sketchy = wine funnel

• MOA: Monamine oxidase inhibitor (MAOI)
  
  • Increases serotonin, NE, and DA

Question 14

What is the main characteristic of atypical depression

Answer 14

• Mood reactivity - improved mood in response to positive events
• Others:
  
  • Vegetative symptoms (increased sleep and appetite)
  • Leaden paralysis
  • Sensitivity to rejection

Question 15

What disorders are associated with basophilic stippling

Answer 15

• Small dots in the periphery of erythrocytes = visualization of ribosome aggregation in cytoplasm of RBCs
• Seen in:
  
  • Lead poisoning
  • Thalassemias
  • Myelodysplastic syndrome

Question 16

Describe the function of Dynein and Kinesin

Answer 16

• Are both microtubule-associated motor proteins that transport cargo from one end of microtubule to another
• Dynein:
  
  • Transports from (+) to (-) end of microtubule
  • Retrograde transport towards the nucleus
    
    • THINK: Negative end Near Nucleus
  • Defect in Kartagener syndrome
• Kinesin:
  
  • Transports from (-) to (+) end of microtubule
  • Anterograde transport away from nucleus
    
    • THINK: Positive end Points to Periphery

Question 17

MOA of Polyethylene glycol

Answer 17

Osmotic laxative

Question 18

MOA of Psyllium

Answer 18

• Bulk-forming laxatives:
  
  • Is an indigestible hydrophilic colloid = will absorb water = distention = peristalsis

Question 19

MOA of Docusate

Answer 19

• Stool surfactant agents (stool softener)
  
  • Facilitate the penetration of stool by water and lipids

Question 20

What is Meniere disease

Answer 20

• Increased pressure and volume of endolymph
• Features:
  
  • Recurrent vertigo
  • Ear fullness/pain
  • Unilateral hearing loss and tinnitus

Question 21

Describe presentation of Vestibular neuritis

Answer 21

• Vestibular neuritis (labyrinthitis):
  
  • Inflammation of vestibular nerve
  • Features:
    
    • Single episode that can last days
    • Severe vertigo but no hearing loss

Question 22

Is HLA-DR3 and HLA-DR4 associated with Type I or Type II DM

Answer 22

Type I DM

Question 23

MRI findings in multiple sclerosis

Answer 23

Periventricular plaques (areas of oligodendrocyte loss and reactive gliosis)

Question 24

Describe the MOA of glucagon as a treatment for beta blocker toxiciy

Answer 24

\

• Glucagon acts on G-protein coupled receptors, increasing intracellular cAMP, and thus increasing release of intracellular calcium during muscle contraction
• This increases heart rate and cardiac contractility

Question 25

How does hepatitis D use Hep B to cause infection

Answer 25

* Hepatitis D antigen must be coated with Hepatitis B surface antigen (HBsAg) in order to penetrate the hepatocyte to cause infection and multiply

Question 26

Where are the different parts of the stomach (fundus, cardia, antrum, body)

Answer 26

Question 27

Cause of gastric varices within the fundus

Answer 27

Portal HTN Splenic vein thrombosis (often due to pancreatitis, pancreatic cancer, or abdominal tumors - splenic vein runs posterior to pancreas)

Question 28

Describe isolation (psych)

Answer 28

* Separating feelings from ideas and events * E.g. Describing murder in detail without an emotional response

Question 29

Describe sublimation (psych)

Answer 29

* _Consciously_ replacing an unacceptable wish with a similar but acceptable course of action * E.g. Redirection of aggression towards father into sports * Vs. Reaction formation - * _Unconsciously_ replacing warded-off feelings by emphasis on its opposite

Question 30

What drugs can be used for nocturnal enuresis

Answer 30

* Imipramine: * TCA * Decreases Non-REM N3 * Short-term treatment * Desmopressin * Decreases urination * Indomethacin: * Decreases renal blood flow, thus decreasing urine formation

Question 31

What structures are contained in the cavernous sinus Describe the presentation of cavernous sinus syndrome

Answer 31

* Collection of venous sinuses on either side of pituitary * Contains CNs III, IV, V1, VI, and occasionally V2, + internal carotid * Cavernous sinus syndrome: * Can be due to pituitary tumor, infection * Presentation: * Ophthalmoplegia (CN II, IV, VI) * Decreased corneal sensation (CN V1) * Horner syndrome * Decreased maxillary sensation (CN V)

Question 32

Describe each stage of the sleep cycle

Answer 32

* To remember EEG waves THINK: _BATS_ **_D_**ream **_B_**ig * Awake (eyes open) * Beta waves * Awake (eyes closed) * Alpha waves * Meditating * Non-REM N1 * Theta waves * Light sleep * Non-REM N2 * Sleep spindles and K complexes * Bruxism (teeth grinding) * Non-REM N3 * Delta waves (lowest frequency) * Deepest sleep * Sleep-walking, night terrors, bed wetting * REM sleep * Beta waves * Loss of motor tone * Dreaming

Question 33

Describ embryology of brain formation

Answer 33

* Prosencephalon à forebrain * Telencephalon * Walls à cerebral hemisphere * Cavities à lateral ventricles * Diencephalon * Walls à thalamus, hypothalamus * Cavities à third ventricle * Mesencephalon à midbrain * Mesencephalon * Walls à midbrain * Cavity à aqueduct * Rhombencephalon à hindbrain * Metencephalon * Walls à pons, cerebellum * Cavity à upper 4^th ventricle * Myelencephalon * Walls à medulla * Cavity à lower 4^th ventricle

Question 34

Supraoptic nucleus of the hypothalamus

Answer 34

* Produces ADH to be stored in posterior pituitary * THINK: Eyeball cup filled with water

Question 35

Paraventricular nucleus of the hypothalamus

Answer 35

* Produces oxytocin to be stored in posterior pituitary * THINK: near valleys filled with love and happiness

Question 36

Pre-optic area of the hypothalamus

Answer 36

* Secretes GnRH à stimulates release of LH and FSH * THINK: Before you even see (pre-optic), the person for who they really are you start secreting sex hormones

Question 37

Dorsomedial nucleus of the hypothalamus

Answer 37

* Stimulates GI * Stimulation = savage behavior and obesity * THINK: green monster on your back making you angry and eating out of jealousy

Question 38

Arcuate nucleus of the hypothalamus

Answer 38

* Releases dopamine and GHRH * Regulates hunger and satiety * THINK: a smile is an arc so the arcuate nucleus gives you the dopey smile you get when you see delicious dessert

Question 39

What tumors show rosenthal fibers

Answer 39

* Pilocytic astrocytoma * Rosenthal fibers – eosinophilic corkscrew fibers * THINK: Chris Rossman (Rosenthal) putting the star (astrocytes) on the top of a child's (tumor of children) christmas tree, so it has a swirly base (corkscrew fibers)

Question 40

What tumor shows perivascular pseudorosettes

Answer 40

* Ependymoma * Perivascular pseudorosettes (tumor cells surrounding vessel) * THINK: Ependymoma = tumor surrounding ventricles; ventricles are open spaces containing body fluids; pseudorosettes is surrounding a vessel which contains body fluids

Question 41

What tumor shows pseudopalisading (surrounding area of central necrosis)

Answer 41

* Glioblastoma multiforme * THINK: * Pseudopallisading looks like a star = astrocyte * Central area is necrotic/dead so this must be an old people tumor – astocyte tumor of adults = glioblastoma multiforme

Question 42

What enzyme catalyzes the formation of ribose sugars in the HMP shunt pathway

Answer 42

Transketolase

Question 43

Treatment of pyruvate dehydrogenase deficiency

Answer 43

§ Ketogenic diet (high fat, low carb diet with moderate levels of protein) § This forces the production of ketone bodies to fuel the body in place of glucose, so less pyruvate is generated via glycolysis § Lysine and leucine are exclusively ketogenic amino acids and cannot be metabolized to pyruvate

Question 44

Compare and contrast conduction aphasia vs. global aphasia

Answer 44

* Conduction aphasia * Damage to arcuate fasciculus (connection between Broca’s and Wernicke’s area) * Broca and Wernicke’s area are intact = fluent speech with intact comprehension * No connection between what you hear and what you say = impaired repetition * Global aphasia: * Both Broca and Wernicke area affected * Influent speech and impaired comprehension

Question 45

What are the 3 C's to remember about toxicity of TCA's?

Answer 45

Cardiac, coma (anti-H1), convulsions (anti-GABA)

Question 46

Compare Parkinson's to Lewy body dementia

Answer 46

* Lewy body:Early onset dementia + Lewy bodies * Vs. Parkinson’s which has late onset dementia + Lewy bodies * Lewy bodies within the cortex (aggregates of a-synuclein) * Vs. Parkinson’s which affects the substantia nigra * Characterized by dementia and visual hallucinations, followed by Parkinsonian features

Question 47

Presentation of Creutzfeldt-Jakob disease

Answer 47

* Rapidly progressive dementia + ataxia + startle myoclonus

Question 48

Cause and presentation of homocystinuria

Answer 48

* Causes: * o Cystathionine synthase deficiency * o Decreased affinity of cystathionine synthase for B6 * o Methionine synthase deficiency * Presentation: * o Homocysteine in urine * o Marfanoid habitus * o Ocular changes (downward and inward lens subluxation – vs. Marfan which is upward) * o CV effects * Homocysteine is _prothrombotic_, which may lead to premature acute coronary syndrome * o Kyphosis * o Intellectual disability

Question 49

Cause and presentation of phenylketonuria

Answer 49

* Due to: * Deficiency in phenylalanine hydroxylase, or * Deficiency in tetrahydrobiopterin cofactor (BH4) * Tyrosine becomes an essential amino acid * Presentation: * o Intellectual disability * o Growth retardation * o Seizures * o Fair skin = inability to make melanin * o Eczema * o Must body odor