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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 area of the posterior aspect of the eye has no photoreceptors?
In the medulla; all the other structures are cortical.
Intrinsic factor (IF)
The optic disk is the blind spot.
IgM; IgD follows shortly thereafter.

2. What three AAs must patients with maple syrup urine disease not eat?
Repolarization is from base to apex and from epicardium to endocardium.
Borrelia recurrentis
Hydatidiform mole
Isoleucine - leucine - and valine

3. What type of collagen is associated with the basement membrane?
Type IV collagen
CD3 molecule. It transmits signals to the inside of the T cell to trigger activation
p -53
Left atrial myxoma

4. What is the most common one? - Location of a duodenal ulcer
Metaplasia (usually to a more protective cell type)
Chromophobe adenoma
Anterior wall of the first part of the duodenum
Rheumatoid arthritis

5. What are the four reasons for hypochromic microcytic anemia with a low MCV?
1. Sideroblastic anemias (i.e. - porphyrin and heme synthesis disorders) 2. Thalassemia 3. Iron deficiency 4. Lead poisoning
Expressive aphasia
Amanita phalloides
They are in ganglia in the PNS.

6. What is the main inhibitor of pyruvate dehydrogenase?
Order of attachment is site 1 - 2 - 3 - 4 - and for release is 4 - 3 - 2 - 1.
Acetyl CoA (pyruvate to acetyl CoA)
Right - sided
Tip of the loop of Henle (1200 mOsm/L)

7. Familial hypercholesteremia is due to a mutation in the LDL receptor gene. What chromosome carries it?
Chromosome 19
Idiotypes
A- T are linked by 2 hydrogen bonds - C- G by 3 hydrogen bonds.
Trichuris trichiura is treated with albendazole.

8. What hormone causes milk letdown?
2 - 4- Dinitrophenol
Oxytocin
Follicular phase
Tertiary hypothyroidism/hypothalamic (Low TRH causes all the rest to be decreased because of decreased stimulation.)

9. What vein drains the lower third of the thoracic wall?
Lithium
Nominal scale (categorical - e.g. - male or female)
Hemiazygous vein
Coombs test

10. Name the following descriptions associated with bacterial endocarditis: x Painless hyperemic lesions on the palms and soles
Janeway lesions
Phallus
Exposure
Goodpasture disease

11. RBCs in the urine
ELISA screens and Western blot confirms the diagnosis.
Bladder carcinoma
Anopheles mosquito
Follicular phase

12. What is the major Ab of the primary immune response?
Dihydrotestosterone
Spermatogonia (type B)
IgM
Eosin

13. Is there more circulating T3 or T4 in plasma?
Stretch receptors prevent overdistension of the lungs during inspiration.
Physostigmine
Selenium (Se)
T4; because of the greater affinity for the binding protein - T4 has a significantly (nearly fifty times) longer half - life than T3.

14. What disease involves microcephaly - mental retardation - cleft lip or palate - and dextrocardia?
Patau syndrome (trisomy 13)
1. Exercise 2. Emergencies (stress) 3. Exposure to cold (The three Es)
Hemolytic uremic syndrome
Hypermyelination of the corpus striatum and the thalamus (seen in cerebral palsy)

15. What subtype of IgG does not bind to staphylococcal A protein?
IgG3
Short - chain fatty acids
The otic ganglion. (These fibers are carried in CN IX. Remember it like this: the - oti - is in both otic ganglion and parotid gland.)
The popliteal artery - the deepest structure in the popliteal fossa - risks injury in a supracondylar fracture of the femur.

16. What are the only two picornaviruses that do not lead to aseptic meningitis?
Ipratropium
Polycystic ovaries
Areas 44 and 45
Rhinovirus and hepatitis A virus

17. 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?
Primary spermatocyte
Nigrostriatal pathways (basal ganglia)
Metabolic acidosis (summary: low pH - high H+ - and low HCO3-)
Chromosome 15 - 17

18. Clue cells are associated with which organism that causes vaginal discharge?
Gardnerella vaginalis
Para - aminohippurate (PAH)
Pancreas and colon
No enzymes are needed. When the stop codon reaches the A site - it results in termination.

19. Describe the organism based on the following information: x Alpha - hemolytic Streptococcus; not lysed by bile; not sensitive to Optochin
Spironolactone (binds to aldosterone receptors)
Stimulus control
Hypervariable region (three per light chain; three per heavy chain)
Streptococcus viridans

20. Name the MCC - Pneumonia in a neutropenic burn patient
Ampicillin and amoxicillin
Pseudomonas sp.
Plasmin
p -53

21. What phase of the cell cycle are the following antineoplastic agents specific for? - 6- Thioguanine
1. Benefits of the procedure 2. Purpose of the procedure 3. Risks of the procedure 4. The nature of the procedure (what you are doing) 5. The alternative to this procedure and its availability (Don't forget the last one; this is where physicians get
S phase
Renal failure
The fasciculus gracilis (Graceful) - which lies closest to the midline of the spinal cord.

22. What is the rate - limiting step in a conduction of a NMJ?
Borrelia recurrentis
enveloped
Common peroneal nerve
The time it takes ACh to diffuse to the postjunctional membrane

23. Which nicotinic receptor antagonist is inactivated to laudanosine?
Atracurium
Infliximab
Passive - aggressive
Rate of absorption

24. What are the four ways to down - regulate the immune system?
Fungi
Streptococcus viridans
Amiloride
1. Decrease concentrations of Ag levels 2. Administer IgG in high concentrations 3. Inhibit B cells with Ag bound to IgG (complexes) 4. Turn off the original T or B cell with anti - Ab

25. What is the term to describe a man who has x The ability to have an erection sometimes and other times not?
Left ventricle and tip of right ventricle
Selective erectile disorder
IF and GTP (eIF for eukaryotes)
Histidine

26. Name five causes for zero - order metabolism.
1. Sustained release 2. IV drip 3. Phenytoin 4. Alcohol 5. Aspirin toxicity
Chromosome 11p
ASD
Action potential

27. Name the most common type or cause - Cellular injury
Western blot
PCT
Hypoxia
Proencephalon diencephalon derivative

28. What diseases are associated with HLA- DR4
3 ATPs by oxidative phosphorylation
Anterior tibial artery
Berry aneurysm
Rheumatoid arthritis and type 1 diabetes (with HLA- DR3)

29. Does light or darkness regulate the pineal gland?
Subdural hematoma is a rupture of the cerebral veins where they enter the superior sagittal sinus.
Light regulates the activity of the pineal gland via the retinal - suprachiasmatic - pineal pathway.
Transmembrane potential (an absolute number)
Hgb F

30. What mineral is a component of cytochrome a/a3?
Copper
Obesity - DM - HTN - multiparity - early menarche - and late menopause
Twelve pairs through twelve thoracic vertebrae. Totaling 31 pairs of spinal nerves.
Medial rectus (CN III) (LR6 SO4)3

31. What is the most common lethal AR disorder affecting white Americans?
Nissl substances; there is a great deal of RER in neuron cell bodies - indicating high protein synthesis.
Pyruvate carboxylase
Bladder cancer
Cystic fibrosis

32. What bone houses the ulnar groove?
Occipital lobe (Anton's syndrome if it is due to bilateral posterior cerebral artery occlusions)
Mean corpuscular hemoglobin concentration (MCHC)
I- cell disease is a result of a genetic defect affecting the phosphorylation of mannose residues.
Humerus (between the medial epicondyle and the trochlea)

33. Neurons in the dorsal horn participate in...
reflexes
Leydig cell tumor
Ductus epididymis - Which is lined by pseudostratified epithelium with stereocilia.
1. Notify police. 2. Try to detain the person making the threat. 3. Notify the threatened victim.

34. Which hepatitis virus is in the Flaviviridae family?
Celiac sprue (gluten - sensitive enteropathy)
Hepatitis C
Hypermyelination of the corpus striatum and the thalamus (seen in cerebral palsy)
Huntington disease

35. What is the term for chronic necrotizing pulmonary infections resulting in permanent airway dilation and associated with Kartagener syndrome?
1. VSD 2. ASD 3. PDA
Uracil
Preload (the load on the muscle in the relaxed state)
Bronchiectasis

36. What structure of the knee is described thus? - Prevents anterior displacement and has lateral - to - medial attachment on the tibia
G0 phase
ACL
Periaortic lymph nodes
Areas 18 and 19

37. Name the antimicrobial agent whose major side effect is listed - CN VIII damage (vestibulotoxic)
Aldosterone Remember - from the outer cortex to the inner layer - Salt - Sugar - Sex. The adrenal cortex gets sweeter as you go deeper.
Aminoglycosides
Middle meningeal artery
IgA

38. What variant of polyarteritis nodosa is associated with bronchial asthma - granulomas - and eosinophilia?
Mitral (bicuspid) valve
Dendrites receive information - whereas axons send information.
Systolic interval decreases secondary to increased contractility; diastolic interval decreases secondary to an increase in heart rate.
Churg - Strauss syndrome

39. What cerebral vessel size is affected in patients with vascular dementia?
Small to medium - sized cerebral vessels
1. Clavulanic acid 2. Sulbactam 3. Tazobactam
The left is a branch of the aortic arch - while the right is a branch of the brachiocephalic trunk.
Hgb F

40. Eating fava beans can produce the Mediterranean type of what deficiency?
Craniopharyngioma
Nodular melanoma
G-6- PD deficiency
Voyeurism

41. Name the DNA virus: x ssDNA; naked; icosahedral; replicates in the nucleus
Fentanyl
Parvovirus
Opioids cause cerebral vasodilation and can result in increased intracerebral pressure.
Lateral compartment of the leg - superficial peroneal nerve

42. What Brodmann area is associated with x Primary motor cortex?
Area 4
Facial expression (the second is vocal intonation)
Fixation (arrested development)
Herpes II

43. What is the most common one? - Neurotransmitter in the brain
produce bile
IgM
GABA - quantitatively
The splenic vein

44. Which anticonvulsant is also used in the treatment of bipolar disorder and for migraine headaches?
Valproic acid
Corynebacterium diphtheriae
Humor
Abs to HBsAg

45. In men - At What embryonic week do the primordial germ cells migrate to the indifferent gonad?
overall dopamine activity
Anterior compartment (it's the blood supply to the posterior compartment)
Week four - and they remain dormant there until puberty.
Prevalence rate

46. What type of DNA library is made from the mRNA from a tissue expressing a particular gene?
cDNA libraries are derived from mRNA - are continuous - and contain no introns or regulatory elements.
Serratus anterior
Hemorrhagic exudates
Lateral hypothalamic zone; lesions here result in aphagia. (Notice the difference between the feeding center and the satiety center; they are in different zones.)

47. The DSM- IV- TR is scored on the basis of five axes of diagnosis. In What axis would you place x Psychosocial and environmental problems (stressors)?
Methanol
Axis IV
Decreases Remember - the carotid sinus reflex attempts to compensate by increasing both TPR and heart rate.
Log - kill hypothesis (follows first order kinetics)

48. During What embryonic week do somites begin to form?
Third week
To provide attachment between contiguous cells and to maintain a semipermeable barrier
Yes. (Remember - Jehovah's witnesses refuse blood transfusions.)
PCT

49. What protein deficiency results in respiratory distress syndrome of newborns?
Deficiency in surfactant
Acetoacetate - acetone - and Beta- hydroxybutyrate
1. Burkitt's lymphoma 2. Nasopharyngeal carcinoma 3. Thymic carcinoma
Dilation of the internal mammary arteries results in erosions on the inner surface of the ribs and is seen as notching.

50. How many base pairs upstream is the prokaryotic TATA box promoter?
Brother Fox (Eichner vs. Dillon). The substituted standard could not apply because the patient had never been competent - so no one knew What the patient would have wanted. Therefore - the decision was based on What a 'reasonable' person would have w
There are two bacterial promoter regions upstream. The TATA box is - 10 base pairs upstream - and the -35 promoter site is self - explanatory.
Left homonymous hemianopsia
Depression