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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 valve abnormality based on the following criteria: x Diastolic murmur - increased right ventricular pressure - left atrial pressure - and atrial to ventricular pressure gradient; decreased left ventricular filling pressure
Langerhans cells
Mitral stenosis
Subatmospheric pressure acts to expand the lung; positive pressure acts to collapse the lung.
Psoas major

2. What viral infection in patients with sickle cell anemia results in aplastic crisis?
Biotin (only if eaten in large quantities)
Oblique fissure
Parasympathetic
Parvovirus B 19

3. If a mother delivers a Rho - positive baby - she should receive...
O2 has a higher driving force but is only one - twenty- fourth as soluble as CO2. CO 2 has a very small partial pressure difference across the alveolar membrane (47-40 = 7 mmHg) - but it is extremely soluble and therefore diffuses readily across the
Rho-immunoglobin
Multiple sclerosis
Golgi tendon organs are stimulated by Ib afferent neurons in response to an increase in force or tension. The inverse muscle reflex protects muscle from being torn; it limits the tension on the muscle.

4. What is the primary screening test used to detect HIV- infected individuals? Confirmatory test?
ELISA is used as a screening test because it is very sensitive; Western blot is used as a confirmatory test because it detects antibodies (protein) to the HIV virus.
C1 inhibitor (C1- INH)
Glucose -6- phosphatase
The removal of Na+ results in the renal tubule becoming negatively charged. The negative luminal charge attracts both K+ and H+ into the renal tubule and promotes HCO3- to enter the ECF and results in hypokalemic alkalosis.

5. What structure of the knee is described thus? - C- shaped shock absorber; aids in attachment of the tibia to the femur via the medial collateral ligament
LDL
Ea (activation energy)
Medial meniscus
A loss of afferent activity indicates a decrease in BP - and an increase in afferent activity indicates an increase in BP.

6. What muscle of the middle ear is innervated by CN VII?
Isoniazid
The stapedius muscle
Bouchard nodes in the PIP joints; Heberden nodes in the DIP joints.
Toxoplasmosis (although you should rule out cerebral abscess due to other organisms)

7. What phase of Interphase is haploid (N)?
IL-8 (IL-1 and TNF- gamma also)
Large segment deletions
Streptococcus pneumoniae
G1 phase; G2 and S phase are diploid (2N).

8. What autoimmune liver disease is characterized by affecting a middle - aged woman with jaundice - pruritus - fatigue - xanthomas - increased direct bilirubin levels - and antimitochondrial Abs?
HBcAb and HBeAb. You see the antibodies c and e.
Primary biliary cirrhosis
Waldeyer's ring
Monosodium urate crystals

9. What two Beta2- agonists are used to produce bronchodilation?
Mean corpuscular volume (MCV)
Metaproterenol and albuterol
unprocessed Ags
Duodenum

10. What is the effect of LH on the production of adrenal androgens?
Decreases Remember - the carotid sinus reflex attempts to compensate by increasing both TPR and heart rate. -------------------------------------------------------------------------------
Cyanocobalamin (B12) deficiency (Folic acid deficiency has only homocystinuria as a sign.)
LH has no effect on the production of adrenal androgens; ACTH stimulates adrenal androgen production.
Varicocele

11. What disease caused by decompression sickness leads to multiple foci of ischemic necrosis that affect the head of the femur - humerus - and tibia?
Caisson disease
Hypertrophic pyloric stenosis due to hypertrophy of the muscularis externa - resulting in a narrowed pyloric outlet
Prodrugs
The urea cycle

12. Name the laryngeal muscle described by the following: x Pulls the arytenoids cartilages closer to the thyroid - relaxing the vocal ligaments and thereby decreasing the pitch
Duodenum
Thyroarytenoid muscles
3'end of the codon (third position) on mRNA and 5' end of the anticodon (first position) on tRNA.
Glossopharyngeal nerve

13. What form of bilirubin can cross the blood - brain barrier?
Afterload
As the standard deviation increases - the greater the chance of error.
Unconjugated free bilirubin
Non - Hodgkin lymphoma

14. What statistical method do you use when analyzing x Cross - sectional studies?
Chi - square.
Alanine cycle
Ampicillin and amoxicillin
Duct cells secrete HCO3- - electrolytes - and water. The acini secrete the enzymes necessary for carbohydrate - nucleic acid - protein cleavage - and emulsification of fats.

15. What is the only organ in the body supplied by preganglionic sympathetic fibers?
eEF-1
Lente or NPH insulin (neutral protamine Hagedorn insulin)
Dimercaprol - penicillamine
Adrenal medulla

16. What aerobic branching rod that is gram positive and partially acid - fast is associated with cavitary bronchopulmonary disease in immunosuppressed patients?
Escherichia coli
Nocardia asteroides
The cupola of the lung is posterior to the subclavian artery and vein. It is the reason one must be cautious when performing subclavian venipuncture.
Transient hypogammaglobinemia of infancy; it usually resolves by age 16 to 30 months.

17. Which two tetracyclines have the highest plasma binding?
Doxycycline and minocycline
Posterior cricoarytenoid muscles
Eosinophil
First - order elimination

18. What paraphilia is defined as x Deriving sexual pleasure from other peoples' pain?
Osteoarthritis
Erythromycin
Sadism
In the dorsal horn of the spinal cord on the primary afferent neurons

19. What artery turns into the dorsalis pedis when it crosses the extensor retinaculum?
Amantadine
Ampulla
B lymphocyte
Anterior tibial artery

20. As what compound do the carbons for fatty acid synthesis leave the mitochondria?
Citrate - via the citrate shuttle
The blood withdrawn is the unconditioned stimulus - inducing the unconditioned response (fainting). The needle is part of the blood - drawing procedure and is the conditioned stimulus (unconditioned and conditioned stimuli are paired) resulting in th
Lesser curvature of the antrum of the stomach
HHV 8

21. Is encapsulated.
Borderline
Gonococcus
Histoplasma capsulatum
7 years old

22. What is the most common one? - Esophageal carcinoma
0.21; it is a fancy way of saying 21% of the air is O2.
Squamous cell carcinoma
Osteosarcoma
Multiple sclerosis

23. What genetic defect is characterized by coarse facial features - gingival hyperplasia - macroglossia - psychomotor and growth retardation - club foot - claw hand - cardiorespiratory failure - and death in the first decade of life?
Entamoeba histolytica (treat with metronidazole)
I- cell disease is a result of a genetic defect affecting the phosphorylation of mannose residues.
Acetyl CoA carboxylase
cDNA - when it is made from mRNA

24. What is the main factor determining GFR?
Non - Hodgkin lymphoma
Subthreshold potential
Glomerular capillary pressure (increased glomerular capillary pressure - increased GFR and vice versa)
1. Fructose -6- phosphate 2. Glucose -6- phosphate 3. Glyceraldehyde -3- phosphate

25. What restriction endonuclease site is destroyed in sickle Beta- globin allele?
Factors II - VII - IX - X - and proteins C and S
Amantadine
B- cell Ag receptors
MstII; changing codon 6 (from A to T) destroys the restriction site.

26. What is the only neuroleptic agent that does not cause hyperprolactinemia?
Aortic insufficiency
Brief psychotic disorder. (In schizophreniform disorder the symptoms last longer than 6 months.)
Clozapine
relaxation

27. What glycoprotein allows platelets to adhere to each other through the use of fibrinogen?
GP IIb/IIIa - Which is why GP IIb/IIIa inhibitors are used in the treatment of acute coronary syndromes
Persistent truncus arteriosus
Sacrococcygeal teratoma
Heinz bodies

28. What urinary metabolite is elevated in pheochromocytoma?
Megaloblastic anemia (decreased absorption of vitamin B12 and folic acid)
Posterior compartment of the leg - tibial nerve
CD3
Vanillylmandelic acid (VMA)

29. Name the antidote - Iron
Positive sense RNA can be used as mRNA. Negative sense RNA cannot be used as mRNA; it requires special RNA- dependent RNA polymerases.
MGB (think EARS)
Deferoxamine - penicillamine
False - negative rate

30. What phase of the cell cycle are the following antineoplastic agents specific for? - Cytarabine
Water - soluble hormones are considered fast - acting hormones.
The liver (in the mitochondria)
S phase
1. Increased amino acid uptake by muscles 2. Decreased protein breakdown 3. Increased protein synthesis

31. What is the DOC for the following protozoal infections? - Leishmaniasis
Alveolar macrophages (dust cells)
Hemostasis
Picornaviridae
Stibogluconate

32. What mineral is an important component of the enzyme xanthine oxidase?
Selegiline
Molybdenum (Mb)
1. Skin 2. Liver 3. Kidney
M

33. Name the ventricular muscle membrane channel: x Closed at rest; depolarization causes channels to open slowly
Zona fasciculata and zona reticularis
1. Epinephrine synthesis 2. Phosphatidyl choline 3. Creatine 4. Methylation of cytosine 5. N- methyl cap of mRNA
Accessory nucleus
Voltage - gated calcium channel

34. What AR syndrome is due to a deficiency of glycoprotein Ib - resulting in a defect in platelet adhesion?
Caplan syndrome
Bernard - Soulier syndrome
Site 2
Nigrostriatal pathways (basal ganglia)

35. What assay is used to identify MHC class I molecules?
B- cell Ag receptors
Adaptive branch. The adaptive branch of the immune system has a slow initiation with rapid responses thereafter.
Microcytotoxic assay
Membrane depolarization is the stimulus to open these channels - which are closed in resting conditions.

36. What does hepatitis D virus need from hepatitis B virus to be infective?
Avoidant
Renal cell carcinoma
HBsAg as its envelope
Anticipation

37. Is the Lac operon activated or inactivated in the presence of both glucose and lactose?
Taenia solium
Series circuit
Inactivated; glucose results in decreased cAMP levels and therefore blocks protein binding between cAMP and CAP.
Posterior

38. What nucleus supplies the preganglionic parasympathetic fibers to the ciliary ganglion?
Edinger - Westphal nucleus (via CN III)
Aversive conditioning
Streptococcus pneumoniae
Centriacinar worse in upper lobes; panacinar worse in base of lower lobes

39. What Brodmann area is associated with x Premotor cortex?
PGE2
Area 6
Lithium
Thyroid hormones

40. Name the type of mutation: x New codon specifies for a stop codon
Ependymoma
The small subunit (40S) binds first.
Astrocytes
Nonsense

41. What thyroid abnormality has the following? - TRH decreased - TSH decreased - T4 increased
Monocytosis
The coding strand is identical to mRNA - and the template strand is complementary and antiparallel.
16S subunit
Graves disease (Increased T4 decreases TRH and TSH through negative feedback.)

42. What is the label given to an individual whose IQ is x 90 to 109
The submandibular ganglion. (Submandibular ganglion innervates the submandibular gland; easy enough.)
Long - term memory is impaired in hippocampal lesions; it is spared in medial temporal lobe lesions.
Average
Nominal scale (categorical - e.g. - male or female)

43. Outburst to cover up true feelings (emotion is covered - not redirected).
Acting out
The lack of glutathione peroxidase activity results in a decrease in NADPH production - leaving glutathione in the reduced state.
Salmeterol
Neutropenia - splenomegaly - and rheumatoid arthritis

44. What ocular muscle x Depresses and adducts the eyeball?
Neisseria gonorrhoeae
Clostridium tetani
Glucocorticoids and amphetamines
Inferior rectus (CN III) (LR6 SO4)3

45. What is the most energy- demanding phase of the cardiac cycle?
Metastatic calcification
Isovolumetric contraction
Sigmoid colon
Glycerol kinase

46. Name the cancer associated with the following chemical agents. (Some may have more than one answer.) x Alkylating agents
Leukemias and lymphomas
Schistosoma haematobium
Macula densa
Gastric ulcer

47. How are flow through the loop of Henle and concentration of urine related?
EF-1 and GTP
Flea - bitten kidney (can also be seen in pyelonephritis)
As flow increases - the urine becomes more dilute because of decreased time for H2O reabsorption.
Primitive neuroectodermal tumors (i.e. - medulloblastomas and retinoblastomas)

48. Name the type of regeneration (i.e. - labile - stable - or permanent) based on the following examples - Skeletal muscle
Mitral valve prolapse
Isocitrate dehydrogenase - a - ketoglutarate dehydrogenase - and malate dehydrogenase
Reverse transcriptase
Permanent

49. What somatoform disorder is described as x Having a F:M ratio of 20:1 - onset before age 30 - and having 4 pains (2 gastrointestinal - 1 sexual - 1 neurologic)?
V wave
CN V3 and the lesser petrosal nerve
Facial expression (the second is vocal intonation)
Somatization disorder

50. What viruses are associated with Cowdry type A intranuclear inclusions?
Mumps and influenza virus
Hypertrophic scar
Waldeyer's ring
Herpes virus I and II