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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. Name the most common type or cause - Hypothyroidism in the United States
Respiratory distress syndrome; treatment with cortisol and thyroxine can increase production of surfactant.
Diverticulosis
Foscarnet
Iatrogenesis

2. Clarke's nucleus is the second ascending sensory neuron of which spinocerebellar tract?
Dorsal spinocerebellar tract; the accessory cuneate nucleus is the second nucleus for the cuneocerebellar tract.
Ionized drugs are water soluble - and since only lipid - soluble drugs can cross biomembranes - an ionized drug cannot cross them without the help of a carrier.
ELISA. It detects anti - p24 IgG.
positive correlation

3. What disease that involves mental retardation - flat face - muscle hypotonia - and a double - bubble sign on radiograph poses an increased risk of Alzheimer's disease and All?
Down syndrome (trisomy 21)
Affinity
Solved as 30% T + 30% A = 60%; therefore - C + G = 40%; then C = 20% and G = 20% (example of Chargaff's rule)
Cryptococcus neoformans

4. What is the term for taking an mRNA molecule and arranging the AA sequence forming a protein?
Monocytosis
IgA
Translation
Gardnerella vaginalis

5. Which hepatitis B serology markers
GABA and glutamic acid
Substantia nigra
Fixation (arrested development)
HBcAb IgM

6. As what compound do the carbons for fatty acid synthesis leave the mitochondria?
Hepatitis D
Psoas major
Parvovirus (it is the only ssDNA virus)
Citrate - via the citrate shuttle

7. What two AAs have a pKa of 10?
Accuracy (think of it as all the trues - because they are the ones correctly identified)
Paramesonephric ducts
Lysine and tyrosine
PGE2 and PGF2a

8. Does REM deprivation interfere with performance on simple tasks?
No - but it does interfere with performing complex tasks and decreases attention to detail. (Be careful post call!)
Zinc (Zn) deficiency
The anterior nucleus of the thalamus
Fading

9. What mast cell mediator is a chemotactic agent?
Alcohol. Nearly 10% of adults have a problem with alcohol.
Eosinophil chemotactic factor A
CD3
Hypertension

10. What AA has a pKa of 13?
Caisson disease
Arginine
Limbic system
Major

11. What type of metal poisoning causes mental retardation - somnolence - convulsions - and encephalopathy?
Phentolamine and phenoxybenzamine
Lead
Red pulp (Remember - Red pulp and RBCs begin with R.)
Type II

12. What is the DOC for CMV retinitis?
Niemann - Pick and Tay- Sachs diseases
Ganciclovir
HMG- CoA reductase
The respiratory system

13. From what pharyngeal pouch is the following structure derived? - Middle ear
Live vaccines
Kawasaki disease
EF-1 and GTP
First M PITS for pharyngeal pouch derivatives

14. Which prophylactic asthmatic agent is an antagonist of LTD4?
Zafirlukast
Low interstitial free Ca2+ concentrations
pK (think of it as where half is base and half is acid)
Toxic or viral hepatitis

15. What is the term to describe a decrease in the cell size and function usually associated with disuse?
Because RPF is markedly decreased - while GFR is only minimally diminished; this results in an increase in FF (remember FF = GFR/RPF).
Desipramine
Atrophy. Disuse can also be due to immobilization - ischemia - aging - and a host of other causes.
Papillary carcinoma of the thyroid

16. How many high - energy bonds does the cycle of elongation cost?
1. Flow independent of BP 2. Flow proportional to local metabolism 3. Flow independent of nervous reflexes
Metronidazole
Peau d'orange
Four high energy bonds - two from ATP in AA activation and two from GTP

17. Regarding neuroleptics - What is the relationship between potency and anticholinergic side effects?
Dorsal motor nucleus of CN X
Monocytosis
Inversely proportional: the higher the potency - the lower the anticholinergic side effects.
Caisson disease

18. What hormone level peaks 1 day before the surge of LH and FSH in the female cycle?
Estradiol
Doxacurium
Alkaline phosphatase
Intention tremor; it is a sign of cerebellar lesions. A tremor at rest (i.e. - pill rolling) is seen in basal ganglia lesions.

19. What CNS developmental abnormality is associated with downward displacement of the cerebellar vermis and medulla compressing the fourth ventricle and leading to obstructive hydrocephalus?
5HT1D
61 codons code for AAs and 3 codons (UAA - UGA - UAG) code for the termination of translation.
Arnold - Chiari malformation type 2
total body water

20. What mineral deficiency in children is associated with poor growth and impaired sexual development?
Salmonella
The fasciculus gracilis (Graceful) - which lies closest to the midline of the spinal cord.
Zinc (Zn) deficiency
Sciatic nerve

21. Which anticonvulsant causes gingival hyperplasia?
Phenytoin (cyclosporine and nifedipine also result in gingival hyperplasia)
CN V1 - the occulomotor division of the trigeminal nerve - is the sensory component of the corneal reflex.
Glioblastoma multiforme
Stratified squamous nonkeratinized epithelium - which has cilia that beat toward the oropharynx.

22. Most sleep time is spent In what stage of sleep?
Stage 2 - which accounts for approximately 45% of total sleep time - with REM occupying 20%.
Malpighian layer (made up of the stratum basale and stratum spinosum)
1. Protest 2. Despair 3. Detachment
GLUT 2

23. Name the ocular lesion; be specific - Right calcarine cortex lesion
Left homonymous hemianopsia
Osteosarcoma
Primary hypoaldosteronism (Addison's disease)
FSH

24. What determines the effective osmolarity of the ICF and the ECF compartments?
Median (think of it as the halfway point)
The concentration of plasma proteins determines effective osmolarity because capillary membranes are freely permeable to all substances except proteins.
Neologisms. Thomas Jefferson noted - 'Necessity obliges us to neologize.' (Abnormal use of neologisms is known as neolalism.)
Leiomyoma

25. Does the heart rate determine the diastolic or systolic interval?
Spermatid
Heart rate determines the diastolic interval - and contractility determines the systolic interval.
T cells - not B cells
Heroin

26. What three substrates control the enzyme PEPCK for the conversion of oxaloacetate (OAA) to pyruvate in the cytoplasm?
1. Cortisol (stimulates PEPCK) 2. Glucagon 3. GTP
Increased GABA levels decrease the likelihood of learned helplessness.
Inversely proportional: the higher the potency - the lower the anticholinergic side effects.
Secretin stimulates the pancreas to secrete a HCO3-- rich solution to neutralize the acidity of the chyme entering the duodenum.

27. What muscle of the middle ear is innervated by CN VII?
The stapedius muscle
Leuprolide
Gerstmann's syndrome; spoken language is usually understood.
S2 - S3 - S4

28. Are more Abs produced in a primary or a secondary immune response?
More Ab is produced in less time in a secondary immune response (shorter lag period).
Prevalence increases. (Incidence does not change.)
Purine nucleoside phosphorylase
Listeria

29. What antihistamine is used in the treatment of serotonergic crisis?
Simple diffusion; it does not use protein - mediated transport
T and B- cells belong to the adaptive branch - whereas PMNs - NK cells - eosinophils - macrophages - and monocytes belong to the innate branch.
produce bile
Cyproheptadine

30. What are the four muscles of mastication?
Suprachiasmatic nucleus
Chromosome 12
Osteosarcoma
1. Masseter 2. Temporalis 3. Medial pterygoid 4. Lateral pterygoid

31. How many days prior to ovulation does estradiol peak in the menstrual cycle?
Angiosarcoma of the liver
2 days prior to ovulation
Crohn disease
If positive - hypotonic urine (osmolarity <300 mOsm/L); if negative - hypertonic urine (osmolarity > 300 mOsm/L)>>

32. What bacterium is diagnosed using the Dieterle silver stain?
Legionella
Hypnopompic hallucinations occur during awakening - whereas hypnagogic hallucinations occur while one is falling asleep.
Gabapentin
Secondary hypercortisolism (pituitary)

33. What cell type in the bone is responsible for bone deposition?
Osteoblast (Remember - blasts make - clasts take)
Uroporphyrinogen I synthetase
T cells - not B cells
Specific rate (e.g. - men aged 55-60)

34. What term describes the inability to recall personal information - commonly associated with trauma?
Acetyl CoA (pyruvate to acetyl CoA)
Sleepwalking is associated with stage 4 and occurs most often in the first third of sleep.
Escherichia coli
Amnesia. (The person is aware of the memory loss.)

35. Name the three methods of vasodilation via the sympathetic nervous system.
Schistosoma haematobium
D- Penicillamine
H 2
1. Decrease alpha -1 activity 2. Increase Beta -2 activity 3. Increase ACh levels

36. Lucid interval
Argyll Robertson pupils
Transient ischemic attack
Epidural hematoma
On the superior body of the posterior wall of the uterus

37. What artery travels with the following veins? - Great cardiac vein
Turcot syndrome
Pneumococcus (Streptococcus pneumoniae)
Left anterior descending artery
IgM

38. What is the most common one? - Histologic variant of breast cancer
The aorta
Empyema
Eaton - Lambert syndrome
Infiltrating ductal carcinoma

39. What oxygen - dependent killing enzyme requires hydrogen peroxide and halide (Cl -) to produce hypochlorous acid?
Conjugated (direct) hyperbilirubinemia - a transport defect
Relaxation of the diaphragm increases the intrapleural pressure (becomes more positive).
By causing rebound insomnia and decrease in REM sleep
Myeloperoxidase

40. What syndrome has loss of deep tendon reflexes - muscle weakness - and ascending paralysis preceded by a viral illness?
Guillain - Barr
cDNA libraries are derived from mRNA - are continuous - and contain no introns or regulatory elements.
1. Skin 2. Liver 3. Kidney
95% in the kidneys; that's why adequate Na+ and fluid intake is essential.

41. A 20-year - old black woman goes to you with nonspecific joint pain - fever - and a malar rash over the bridge of her nose and on her cheeks. This is a classic example of What autoimmune disease? What are three autoantibody tests you could order to m
SLE; ANA - anti - dsDNA and anti - Sm (anti - Smith)
Impotence
Clarke's nucleus
Because creatinine is filtered and a small amount is secreted

42. What is the most common one? - Type of ASD
Blood
Ostium secundum defects
Toxoplasmosis
Zafirlukast

43. What is the only Plasmodium that is quartan?
Plasmodium malariae; the others are tertian.
Adrenal medulla
Osteitis fibrosa cystica (von Recklinghausen disease)
Coprophilia

44. Name the type of graft described by these transplants: x From one site to another on the same person
Autograft
Venlafaxine. (It also has a mild dopaminergic effect.)
Chloramphenicol
During stage 3 and 4 (remember - it is called deep sleep.)

45. When is the surface tension the greatest in the respiratory cycle?
Isotonic contraction
Eosinophilic exudates
Surface tension - the force to collapse the lung - is greatest at the end of inspiration.
Adhesions and hernias

46. What is the most common Ig deficiency?
Antigenic determinant (epitope)
Null hypothesis (what you hope to disprove)
IgA deficiency; patients commonly present with recurrent sinopulmonary infections and GI disturbances.
Neurofibromatosis I (chromosome 22q is with neurofibromatosis II and no Lisch nodules)

47. What is the most common one? - Cardiac tumor
Left atrial myxoma
Medulla blastoma
Plasmodium falciparum
The systemic veins have the largest blood volume - and the pulmonary veins have the second largest blood volume in the cardiovascular system. They represent the reservoirs of circulation.

48. What is the most common one? - Benign lesion that affects the breast
Left homonymous hemianopsia
Ego
Peroxidase - Which is also needed for iodination and coupling inside the follicular cell
Fibrocystic change of the breast

49. Name the antimicrobial agent whose major side effect is listed - Cholestatic hepatitis
Methicillin
Free ionized Ca2+
Erythromycin
The cat

50. What is the formula to calculate IQ?
(MA/CA) x 100 = IQ score - where MA = mental age and CA = chronological age
PGI2
Chromosome 20q (deficiency in adenosine deaminase)
M