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USMLE Step 1 Prep

Subjects : health-sciences, usmle-step-1

Instructions:

Answer 50 questions in 15 minutes.
If you are not ready to take this test, you can study here.
Match each statement with the correct term.
Don't refresh. All questions and answers are randomly picked and ordered every time you load a test.

This is a study tool. The 3 wrong answers for each question are randomly chosen from answers to other questions. So, you might find at times the answers obvious, but you will see it re-enforces your understanding as you take the test each time.

1. What primary acid - base disturbance is caused by a gain in fixed acid forcing the reaction to shift to the left - decreasing HCO3- and slightly increasing CO2?
Borrelia recurrentis
Albinism. Tyrosine is converted to melanin by the enzyme tyrosinase.
Metabolic acidosis (summary: low pH - high H+ - and low HCO3-)
No change in length

2. What type of acute metal poisoning involves stomach and colon erosion and acute tubular necrosis?
Nigrostriatal pathways (basal ganglia)
Amyotrophic lateral sclerosis (Lou Gehrig's disease) is a LMN lesion at the level of the lesion and UMN lesion below the level of the lesion.
Mercury
Decreases

3. What virus is associated with body cavity large B- cell lymphomas?
Hirschsprung disease
HHV-8
Eosin
Acting out

4. What is the term for a schizophrenic episode lasting longer than 30 days with full return to former functioning capacity?
Osteoblasts (Remember - they modulate the function of osteoclasts.)
Brief psychotic disorder. (In schizophreniform disorder the symptoms last longer than 6 months.)
Supraspinatus and infraspinatus
B cells are mainly found in the peripheral white pulp and germinal centers in the spleen.

5. Name the antimicrobial agent whose major side effect is listed - Dental staining in children
Saltatory conduction
Protease - integrase - and reverse transcriptase
6 ATPs (remember 2 pyruvates per glucose are produced - and 2 NADHs result from production of acetyl CoA - so 6 ATPs)
Tetracycline

6. What type of fiber or fibers are carried in (answer motor - sensory - or both) x Dorsal root ganglion?
Glutamine
Phase 1
Saccule and utricle
Sensory

7. How does ventricular depolarization take place - base to apex or vice versa?
1. Fibrillary protein 2. Amyloid protein 3. Glycosaminoglycans
Glutamine and aspartate
Depolarization is from apex to base and from endocardium to epicardium.
Melanoma - cancer of the stomach and bladder

8. What is the most common one? - Malignancy in children
Arginine
All
Gradient - time system
Displacement

9. How many bases upstream is the eukaryotic TATA box promoter?
Chylomicrons
total body water
Quaternary structure
There are two eukaryotic upstream promoters. The TATA box is -25 base pairs upstream; the CAAT box is -75 bases upstream.

10. With What three enzymes is thiamin pyrophosphate (TPP) associated?
Succinylcholine
Chromosome 5p
Group A Beta- hemolytic streptococci
1. a - Ketoglutarate dehydrogenase 2. Pyruvate dehydrogenase 3. Transketolase Thiamine pyrophosphate (TPP) functions as a coenzyme vital to tissue respiration. It is required for the oxidative decarboxylation of pyruvate to form acetyl - coenzyme A -

11. What is the name of the regulatory protein that covers the attachment site on actin in resting skeletal muscle?
Tropomyosin
eIF-2 in the P site
Succinyl CoA
Zona fasciculata and zona reticularis

12. What changes does more negative intrathoracic pressure cause to systemic venous return and to the pulmonary vessels?
Group A Beta- hemolytic streptococci
For males - HTN; for females - pregnancy.
Splitting
Promotes systemic venous return into the chest and increases the caliber and volume of the pulmonary vessels

13. What part of a neuron receives information?
Dendrites receive information - whereas axons send information.
Acetyl CoA carboxylase
Stylopharyngeus muscle is innervated by CN IX; all other pharyngeal muscles are innervated by CN X.
Increases Remember - the carotid sinus reflex attempts to compensate by increasing both TPR and heart rate. -------------------------------------------------------------------------------

14. Which form of melanoma carries the worst prognosis?
No CHO - AA - ketones - or peptides are left in the tubular lumen.
Increases Remember - the carotid sinus reflex attempts to compensate by increasing both TPR and heart rate. -------------------------------------------------------------------------------
1. Autoimmune hypersplenism 2. Trauma 3. Anemia 4. Spherocytosis 5. Sickle cell anemia
Nodular melanoma

15. What type of hallucination occurs during awakening?
Dopamine levels rise with waking; dopamine is associated with wakefulness.
Strongyloides stercoralis is treated with thiabendazole.
Hypnopompic hallucinations occur during awakening - whereas hypnagogic hallucinations occur while one is falling asleep.
Megaloblastic anemia (decreased absorption of vitamin B12 and folic acid)

16. What is the most widely used class of antidepressants?
Anemic patients have a depressed O2 content because of the reduced concentration of Hgb in the blood. As for polycythemic patients - their O2 content is increased because of the excess Hgb concentrations.
All
SSRIs
Affinity (one of each)

17. Testing of a drug in a small group of volunteers without the disease is a component of which phase of clinical drug testing?
Necrophilia
Phase 1
Phase II
Hypertrophy

18. What enzyme of the purine salvage pathway is deficient in the following? - Selective T- cell immunodeficiency
Hemochromatosis
Purine nucleoside phosphorylase
Omphalocele and gastroschisis
Clostridium botulinum

19. What is the name of the 12- step program believed to be the most successful for the treatment of alcohol abuse?
Acetyl CoA carboxylase
Alcoholics Anonymous
PKU
Niclosamide

20. What two muscles do you test to see whether CN XI is intact?
Trapezius and sternocleidomastoid
Osteoarthritis
Primary spermatocyte
PALS (Parietolateral lymphocytic sheath)

21. What component of the vascular system is most sensitive to the effects of calcium channel blockers?
Leukotriene B4 (LTB4)
Arterioles
Cystadenocarcinoma
Concrete operations (6-12 years)

22. What type of bilirubin is found in neonatal jaundice?
Mitochondria
Indirect or unconjugated
L2 to L4 (L2 to L4 - thigh; L4 to S3 - leg)
Parafollicular C cells

23. What syndrome is characterized by bilateral medial temporal lobe lesion - placidity - hyperorality - hypersexuality - hyperreactivity to visual stimuli - and visual agnosia?
Ritodrine and terbutaline
Medial collateral ligament
Kl
Ribozymes

24. Are the following major or minor Jones criteria of rheumatic fever? - Sydenham chorea
Malingering
Spleen
Major
The resistance increases 16- fold.

25. What type of crystals are associated with gout?
Class IV
Monosodium urate crystals
Alanine and glutamine
Conn syndrome (primary hyperaldosteronism)

26. What enzyme converts androgens to estrogens?
Aldehyde dehydrogenase
Trapezius and sternocleidomastoid
Aromatase
1. Less than 3 cm 2. Clean base 3. Level with the surrounding mucosa

27. What sex cell tumor causes precocious puberty - masculinization - gynecomastia in adults - and crystalloids of Reinke?
Paneth cells
Leydig cell tumor
H1 histones
Phase 1

28. What is the rate - limiting step in a conduction of a NMJ?
Prophase of meiosis I (between 12th and 22nd week in utero)
The time it takes ACh to diffuse to the postjunctional membrane
Rigors - leukopenia - decrease in blood pressure - and increase in temperature
Inulin

29. What is the only excitatory neuron in the cerebellar cortex - and What is its neurotransmitter?
Deferoxamine - penicillamine
Langerhans cells
Simon focus
The granule cell is the only excitatory neuron in the cerebellar cortex - and it uses glutamate as its neurotransmitter. All the other cells in the cerebellum are inhibitory neurons - and they use GABA as their neurotransmitter.

30. What hypothesis states that the findings of a test are a result of chance?
Inhaled anesthetics with low lipid solubility have low potency (directly related) - so they have rapid induction and rapid recovery; vice versa for drugs with high lipid solubility.
Sertoli cell
Null hypothesis (what you hope to disprove)
Primary spermatocyte

31. What is the most common one? - Thyroid cancer
Left coronary artery
Mast cells
Papillary carcinoma
Choriocarcinomas and trophoblastic tumors

32. Do the following structures pick up stain from hematoxylin or eosin? - Nucleoli
There is a difference; it takes about 7 to 8 half - lives to reach mathematical steady state and 4 to 5 half - lives to reach clinical steady state.
Hematoxylin
The rate of Beta- oxidation
Transposons

33. What two sugars can be used to produce cerebrosides?
Glucose and galactose
Streptococcus viridans
G-6- PD deficiency; pyruvate kinase deficiency is second.
Prefrontal cortex; it is in front of the premotor area.

34. What is the enzyme for the oxidative reaction in glycolysis?
Proencephalon diencephalon derivative
Glyceraldehyde dehydrogenase
Semicircular duct
Coxiella burnetii

35. What are the two precursors of heme?
Dapsone
It decreases insulin secretion.
Glycine and succinyl - CoA
Clostridium perfringens

36. What nerve supplies general sensation to the anterior two - thirds of the tongue?
T and B- cells belong to the adaptive branch - whereas PMNs - NK cells - eosinophils - macrophages - and monocytes belong to the innate branch.
Lingual nerve of CN V3
Glyceraldehyde dehydrogenase
CN IX and X

37. Does being a female physician increase or decrease the risk of suicide?
Impotence
Being a female physician increases the risk of suicide nearly four times the general population.
Hyaluronic acid (all sulfates bind to the core protein)
Flucytosine

38. Are the following major or minor Jones criteria of rheumatic fever? - Elevated acute phase reactants (e.g. - ESR)
The fasciculus gracilis (Graceful) - which lies closest to the midline of the spinal cord.
Pseudomonas sp.
Minor
Type III hypersensitivity reaction

39. Regarding the Lac operon - for What do the following genes code? - Z gene
Beta- Galactosidase
S phase
Posterior chamber
Recovery and death

40. What syndrome is associated with the following brainstem lesions? - Contralateral corticospinal and medial lemniscus tract deficits and an ipsilatera medial strabismus secondary to a lesion in CN VI
Pseudohyphae
Medial pontine syndrome
Neisseria gonorrhea (history of STD in patient with monoarticular infectious arthritis: think gonococcus)
Flurazepam

41. Is hirsutism a side effect of estrogen or progestin therapy?
HPV serotypes 16 - 18 - 31 - and 33
28 L - 40% of body weight
Indirect hernia passes in the inguinal canal; a direct hernia passes directly through Hesselbach's triangle.
Progestin

42. At the apex of the lung - What is the baseline intrapleural pressure - and what force does it exert on the alveoli?
Renal failure
Baseline apical intrapleural pressure is -10 cm H2O (more negative than the mean) resulting in a force to expand the alveoli.
Neutropenia - splenomegaly - and rheumatoid arthritis
Penicillamine - EDTA (calcium disodium edetate) - or dimercaprol

43. Name the antimicrobial agent whose major side effect is listed - Hemolytic anemia
Nitrofurantoin
21-Beta- Hydroxylase deficiency leads to hypotension - hyponatremia - and virilization.
Ag - Ab complexes. The alternative pathway protects without use of Abs; the pathogen is the stimulus.
HBcAb IgM - HBV- DNA - HBeAg - HBsAg

44. Abs to what hepatitis B Ag provide immunity?
Abs to HBsAg
Proencephalon diencephalon derivative
Excess estradiol in the blood
unprocessed Ags

45. Are hydrolysis - oxidation - and reduction phase I or II biotransformations?
Osteosarcoma
Phase I
95% in the kidneys; that's why adequate Na+ and fluid intake is essential.
Third week

46. What reflex increases TPR in an attempt to maintain BP during a hemorrhage?
The carotid sinus reflex
Total lung capacity (TLC)
Cardiac output
Somatotrophins are stimulated by IGF-1 - and they inhibit GH secretion. GHRH stimulates GH secretion.

47. What area of the brain is responsible for emotion - feeding - mating - attention - and memory?
In eukaryotes transcription occurs in the nucleus and translation in the cytoplasm.
The limbic system
Myeloschisis All except occulta cause elevated - fetoprotein levels.
Positive reinforcement

48. Name the product or products of arachidonic acid: x Vasoconstriction and platelet aggregation produced by platelets
Kinesins. Dynein generates retrograde transportation of information.
Red pulp (Remember - Red pulp and RBCs begin with R.)
PGE2
TXA2

49. From What embryonic structure are the following structures derived? - The right and left atria
Acetyl CoA carboxylase
Primitive atrium
Dyspareunia. It is a common complaint in women who have been raped or sexually abused.
Common and internal carotid arteries

50. Which hepatitis B Ab indicates low transmissibility?
Transcortical aphasia
Simon focus
Myasthenia gravis
HBeAb