UWorld Sim 1

Question 1

what is the pathogenesis in acute respiratory distress syndrome and what will you see

Answer 1

1. Alveolar insult (sepsis, aspiration, pneumonia, trauma, pancreatitis)
2. pro-inflammatory cytokines being released
3. PMNs and release of toxic mediators
4. Capillary endothelial damage and increase in vessel permeability
5. leak of protein rich fluid in the alveoli
6. formation of intra-alveolar hyaline membranes and pulmonary edema

*note loss of surfactant also contributes to alveolar collapse

Abnormal chest x-ray (bilateral lung opacities)
Respiratory failure within 1 week of alveolar insult
Decreased PaO2/FiO2 (<300, hypoxemia due to increased intrapulmonary shunting and diffusion abnormalities)
Symptoms of respiratory failure are not due to HF/fluid overload

-impaired gas exchange, decreased lung compliance, pulmonary hypertension

Question 2

globus sensation/hystericus/pharyngeus

Answer 2

common abnormal sensation of foreign body, tightness, or fullness in throat without accompanying findings of esophageal obstruction

• worsens when swallowing spit but better when eating and drinking
• considered a functional disorder of the esophagus

Question 3

what is the one vitamin you do NOT want in excess when pregnant?

Answer 3

vitamin A

• accumulates in the stellate cells of the liver and is not readily excreted in the urine
• too much in the first trimester (during organogenesis) can result in fetal microcephaly, cardiac anomalies, early epiphyseal closure, growth retardation, and spontaneous abortion

Question 4

DNA laddering

Answer 4

• appearance of DNA fragments in multiples of 180 base pairs

- sensitive indicator of apoptosis

Question 5

what are the filaments used in each type of cell connection

Answer 5

tight junction: claudin and occludin

adherens junction: cadherins

desmosome: cadherins with intermediate filaments

gap junction: connexons made up of connexins

hemidesmosome: integrin, fibronectin/laminin, ECM/collagen

Question 6

what is the primary concern of both anterior and posterior dislocations of the knee join

Answer 6

injury to the popliteal artery

Question 7

what should you be concerned about in a case with:

penetrating trauma to the popliteal fossa

OR

blunt trauma to the lateral knee

Answer 7

tibial nerve

OR

common peroneal nerve

Question 8

nummular eczema

Answer 8

pruritic, coin-shaped, erythematous patches

Question 9

being an angry person then going and playing sports to get the aggression out

Answer 9

sublimation

Question 10

ligand binding to a tyrosine kinase receptor results in formation of….

Answer 10

receptor dimers and a conformational change that exposes tyrosine kinase active sites

Question 11

Chiari I vs Chiari II vs Dandy-Walker

Answer 11

Chiari I –> ectopia of cerebellar tonsils inferior to foramen magnum (1 structure), usually asymptomatic in childhood but with cough/headaches in adulthood and cerebellar symptoms

Chiari II –> herniation of cerebellar vermis and tonsils (2 structures) through foramen magnum with aqueductal stenosis, noncommunicating hydrocephalus, usually with lumbosacral myelomeningocele and may present as paralysis/sensory loss at and below the level of the lesion

Dandy-Walker –> agenesis of cerebellar vermis leads to cystic enlargement of 4th ventricle that fills the enlarged posterior fossa, associated with noncommunicating hydrocephalus and spina bifida

Question 12

female with primary amenorrhea, absent uterus and upper vagina, cryptorchid (undescended testes), minimal to absent pubic hair, yes to breast development

Answer 12

x-linked defect of androgen receptor (complete androgen insensitivity)

Question 13

premature neonate with impaired BP in premature infants, altered level of consciousness, bulging fontanelle, hypotension, seizures, coma

Answer 13

Neonatal intraventricular hemorrhage

• bleeding into ventricles
• increased risk in premature and low-birth-weight infants
• originates in germinal matrix (highly vascularized layer within the subventricular zone)
• due to reduced glial fiber support and impaired autoregulation of BP in premature infants

Question 14

cisplatin and carboplatin

Answer 14

cross-links DNA

-used for testicular, bladder, ovary, and lung carcinomas

adverse effects: nephrotoxicity, peripheral neuropathy, and otoxicity (tinnitus and hearing loss by damaging hair cells within the organ of corti of the cochlear membranous labyrinth)

prevent nephrotoxicity with amifostine (free radical scavenger) and chloride (saline) diuresis

Question 15

which medications can cause interstitial lung diseases

Answer 15

bleomycin, busulfan, amiodarone, methotrexate

Question 16

how do nitrates affect heart and blood vessels

Answer 16

increase heart rate and decrease end-diastolic left ventricular volume

*just think about it… since it causes venodilation the amount of blood going to the heart will decrease so the heart will have to pump faster to compensate for that

Question 17

what mutation will you see in achondroplasia

Answer 17

AD mutation of FGFR3 gene

Question 18

what is the purpose of the N-terminal sequence of mRNA

Answer 18

this is what signals it to go to the RER and if not then it’ll get translated in the cytosolic ribosomes and will accumulate in the cytoplasm

Question 19

fetal ultrasound with ascites, large bilateral pleural effusions, and small pericardial effusions from a couple who are from southeast asia

Answer 19

hemoglobin barts (4 gene loss: alpha thalassemia)
-this means both parents must have 2 gene losses and their phenotype would be a mild microcytic anemia

Question 20

what cell is messed up if a male pt has fertility troubles, normal serum testosterone, and low gonadal testosterone

Answer 20

Sertoli cells cause they do not release androgen binding protein like they should in order to keep the testosterone concentration high in the testes/seminiferous tubules thats needed for normal sperm production and maturation

Question 21

what should you expect to see in a pt with exertional dyspnea and right ventricular hypertrophy

Answer 21

this pt has pulmonary arterial hypertension

you will see pulmonary endothelial dysfunction

Question 22

what should be top on your differential if you have a young woman with VERY heavy menstrual periods (to the point where blood transfusions are needed after menses)

Answer 22

leiomyoma (uterine fibroids)–> benign uterine smooth muscle tumor that can result in endometrial venous ectasia which can lead to heavy menses

note: submucosal/intracavitary fibroids are particularly associated with anemia
distortion of the intrauterine cavity can result in reproductive difficulties

Question 23

tumor composed of polygonal, eosinophilic cells that stain positive for neuropeptides (chromogranin and synaptophysin)

Answer 23

carcinoid tumor
-typically arise in GI tract or bronchus and can be associated with dramatically elevated levels of vasoactive compounds like serotonin leading to carcinoid syndrome (facial flushing and diarrhea)

Question 24

most frequently involved site of crohns

Answer 24

terminal ileum

-may also have aphthous ulcers of the mouth and perianal disease (fissures and abscesses)

Question 25

alpha1 and 2 along with beta1 and 2

what are their second messengers when stimulated

Answer 25

a1 = IP3 (increase)
a2 = cAMP (decrease)

beta1 and 2 = cAMP increase

Question 26

where does the recurrent laryngeal nerve lie and what does it supply

Answer 26

circles around the aortic arch off of the vagus nerve

All the intrinsic muscles of the larynx

• posterior and lateral cricoarytenoid
• oblique and transverse arytenoid
• thyroarytenoid

Question 27

patient with fatigue and painless goiter

Answer 27

hashimotos

• diffuse lymphocytic infiltration of thyroid gland by B and T cells specific for thyroid antigens (lymphoid germinal centers and destruction of thyroid follicles)
• hurthle cells also seen

Question 28

inheritance of duchenne muscular dystrophy

Answer 28

x-linked recessive

Question 29

birds beak on barium swallow and food feeling like its stuck in throat

Answer 29

achalasia

-inflammation and degeneration of neurons in esophageal wall

Question 30

as sample size increases what value decreases

Answer 30

standard error (less variability in data points)

Question 31

peutz-jeghers syndrome

Answer 31

AD

• numerous hamartomas throughout GI tract along with hyperpigmented macules on mouth, lips, hands, and genitalia
• associated with increased risk of breast and GI cancer

Question 32

what can acanthosis nigricans be a sign on

Answer 32

insulin resistance or malignancy

-more likely to be malignancy if it appears suddenly and spreads quickly (usually GI or lung malignancy)

Question 33

transduction

Answer 33

transfer of genes via bacteriophage

Question 34

transformation

Answer 34

naked DNA uptake from surrounding areas

Question 35

conjugation

Answer 35

bacterial sex with pilus

Question 36

homeobox (HOXA13) gene expression

Answer 36

hand-foot-genital syndrome

-hypoplastic fingers and mullerian fusion abnormalities (uterus didelphys)