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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 is the limited portion of a large Ag that will actually be recognized and bound to an Ab and that contains approximately five to six amino acids or four to five hexose units?
CN VII
Erythromycin
Nitroprusside
Antigenic determinant (epitope). (Idiotypes bind to epitopes.)

2. What vitamin is an important component of rhodopsin?
Vitamin A
Metanephros
Expiratory reserve volume (ERV)
antiemetic

3. What is the site of action of the following? - K+- sparing diuretics
Cori cycle
Early collecting duct
Anorgasmia. (The overall prevalence is 30%.)
Riboflavin (B2)

4. Is a nicotinic receptor agonist.
1. TTP 2. Lipoic acid 3. Coenzyme A from pantothenate 4. NAD(H) (from niacin or tryptophan) 5. FADH2 (from riboflavin)
Anorgasmia. (The overall prevalence is 30%.)
Succinylcholine
Lower extremity and lower trunk information travels in the dorsal spinocerebellar tract. The upper trunk and extremity information travels in the cuneocerebellar tract. (Cuneocerebellar and fasciculus cuneatus both apply to upper extremities.)

5. What Ig prevents bacterial adherence to mucosal surfaces?
Rhombencephalon
In the supraoptic nuclei of the hypothalamus; it is stored in the posterior pituitary gland.
Zollinger - Ellison syndrome
IgA

6. What are the two best indices of left ventricular preload?
Metabolic acidosis (summary: low pH - high H+ - and low HCO3-)
Trazodone
Papule
LVEDV and LVEDP (left ventricular end - diastolic volume and end - diastolic pressure - respectively)

7. What is the MCC of the following meningitides? - In those 12 months to 6 years of age
Haemophilus influenzae type B
Peutz - Jeghers syndrome
1. Sustained release 2. IV drip 3. Phenytoin 4. Alcohol 5. Aspirin toxicity
Dilation of efferent arteriole

8. Describe What type of fluid is either gained or lost with the following changes in body hydration for the ECF volume - ICF volume - and body osmolarity - respectively: x ECF: increase; ICF: no change; body: no change
Lewy bodies
Proencephalon
Anterior compartment of the thigh - femoral nerve
Gain of isotonic fluid (isotonic saline)

9. What enzyme of the TCA cycle also acts as complex II of the ETC?
Hepatitis E
Succinate dehydrogenase
Eosin
Chromosome 15 - 17

10. What is the best measure of total body vitamin D if you suspect a deficiency?
Adenovirus
Serum 25- hydroxy- vitamin D (25- OH- D)
Pubis - ilium - and ischium
1. TTP 2. Lipoic acid 3. Coenzyme A from pantothenate 4. NAD(H) (from niacin or tryptophan) 5. FADH2 (from riboflavin)

11. What are the two broad - spectrum penicillins?
Adenocarcinoma (because of Barrett esophagus)
Microglia. All others are neuroectodermal derivatives.
Ampicillin and amoxicillin
Area 22 and occasionally 39 and 40

12. What is the term for a large VSD that leads to pulmonary HTN - RVH - and cyanosis due to right - to - left reversal of the shunt?
Eisenmenger syndrome - which can also occur with any left - to - right shunt
Simon focus
O2 affinity increases with a decrease in the p50 - making O2 more difficult to remove from the Hgb molecule.
Fibroadenoma

13. Name the MCC - Pneumonia in an HIV- positive patient with CD4 less than 200
No. Remember - tests do not diagnose - they confirm or refute your diagnosis. Also - diagnosis of MI requires two of three criteria: chest pain consistent and characteristic of MI - elevated cardiac enzymes consistent with MI - and ST segment elevati
Pneumocystis carinii
Hyperplasia
Peroxidase - Which is also needed for iodination and coupling inside the follicular cell

14. Do you monitor heparin's therapeutic levels by PT or PTT?
Lactulose
Y - W-135 - and C and A capsular polysaccharides
0.21; it is a fancy way of saying 21% of the air is O2.
Heparin - intrinsic pathway - PTT; warfarin - extrinsic pathway - PT (mnemonic: hPeT - wPiTT)

15. If free water clearance (CH2O) is positive - What type of urine is formed? And if it is negative?
Streptococcus agalactiae (Group B Streptococcus - or GBS)
Thymus gland. (Thymus gland is essential for T cell maturation.)
Diffusion rate is indirectly proportional to membrane thickness and is directly proportional to membranes surface area.
If positive - hypotonic urine (osmolarity <300 mOsm/L); if negative - hypertonic urine (osmolarity > 300 mOsm/L)>>

16. Regarding neuroleptics - What is the relationship between potency and anticholinergic side effects?
Adenocarcinoma of the cervix
Multiple sclerosis
Alveoli; they are part of the respiratory portion.
Inversely proportional: the higher the potency - the lower the anticholinergic side effects.

17. What nematode is known as threadworms? What is the treatment?
Listeria
4.5 years old (Alphabetic order except with a diamond last: circle - cross - rectangle - square - triangle)
Proencephalon diencephalon derivative
Strongyloides stercoralis is treated with thiabendazole.

18. What serves as a marker of endogenous insulin secretion?
It increases Ca2+ excretion from the kidney and increases bone mineralization.
C- peptide levels
EF-2 and GTP
Nicotinic acid - because its side effects include hyperuricemia and exacerbation of ulcers.

19. Name the associated chromosomal translocation - Follicular lymphoma
Left anterior descending artery
alpha2- Receptors
Lateral rectus (CN VI) (LR6 SO4)3
Chromosome 14 - 18

20. Which dopamine receptor excites the direct pathway of the basal ganglia?
Diazoxide
Glioblastoma multiforme
D1 receptor; inhibition of the direct pathway occurs through the D2 receptors.
Tay- Sachs disease

21. What complement factor deficiency leads to x Increased susceptibility to pyogenic infections?
Vagus nerve
C3 deficiency
Under normal resting conditions no - but they are strongly stimulated when PO2 arterial levels decrease to 50 to 60 mm Hg - resulting in increased ventilatory drive.
Meckel diverticulum

22. What is the most common opportunistic infection of the CNS in HIV?
Axis IV
Adenocarcinoma (because of Barrett esophagus)
Sexual aversion disorder
Toxoplasmosis

23. Are antibiotics helpful in treating a disease caused by a prion?
No. Prions are infectious proteins - so antibiotics are useless.
Sporothrix schenckii
Primary follicle (in the white pulp)
The alveolar PO2 and PCO2 levels

24. What branch off the vertebral artery supplies x The ventrolateral two - thirds of the cervical spinal cord and the ventrolateral part of the medulla?
Anterior spinal artery
Anemia of chronic disease
Sympathetic nervous system
hypophosphatemia

25. What tract carries the ipsilateral dorsal column fibers from the upper limbs in the spinal cord?
The fasciculus cuneatus
Job syndrome
Stage 2 - which accounts for approximately 45% of total sleep time - with REM occupying 20%.
Thymic epithelial cells - dendritic cells - and macrophages

26. Both submandibular and sublingual glands are innervated by CN VII (facial) and produce mucous and serous secretions. Which one mainly produces serous secretions?
Submandibular gland produces mainly serous and the sublingual gland produces mainly mucous secretions.
Intrinsic. The extrinsic pathway is activated by the release of tissue factors.
Thioridazine
Left atrium and tip of the right atrium

27. Is bone deposition or resorption due to increased interstitial Ca2+concentrations?
Bone deposition increases with increased Ca2+ or PO 4- concentrations - whereas resorption (breakdown) is increased when there are low levels of Ca2+ or PO4-.
Diffusion rate is indirectly proportional to membrane thickness and is directly proportional to membranes surface area.
1. C5a 2. Leukotriene B4 3. IL-8 4. Bacterial peptides
Marrow failure - cancer - and leukemia

28. What is the most common one? - Proliferative abnormality of an internal organ
C wave
prognostic predictors
To provide attachment between contiguous cells and to maintain a semipermeable barrier
BPH

29. In an adrenergic nerve terminal - Where is dopamine converted to NE? By what enzyme?
Dopamine is converted into NE in the vesicle via the enzyme dopamine - Beta - hydroxylase.
Right - sided valves
Osteoclasts
Granulosa/thecal cell tumor of the ovary

30. What is a palpable - elevated solid mass up to 0.5 cm?
Mitral valve stenosis
Herpesvirus
Papule
Mean

31. What protein carries free fatty acids to the liver?
Albumin
Chromosome 14 - 18
Clavicle - acromion - and glenoid fossa of the scapula and the humerus
Second M PITS for pharyngeal pouch derivatives

32. The most frequent number occurring in a population is what?
Mode
1. Protest 2. Despair 3. Detachment
Trypanosoma cruzi
SLE; ANA - anti - dsDNA and anti - Sm (anti - Smith)

33. What is the label given to an individual whose IQ is 70 to 79
IgA deficiency; patients commonly present with recurrent sinopulmonary infections and GI disturbances.
Preganglionic sympathetic neurons
Pneumothorax
Borderline

34. Which is the conditioned response - the conditioned stimulus - the unconditioned response - the unconditioned stimulus in this case? A patient has blood withdrawn and faints. The next time she goes to have blood taken - she faints at the sight of the
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
1. Less than 3 cm 2. Clean base 3. Level with the surrounding mucosa
Bcl -2
Superior

35. What vasculitis affects a 30-year - old Asian female having visual field deficits - dizziness - decreased blood pressure - and weakened pulses in the upper extremities?
Estrogens are 18- carbon steroids. (Removal of one carbon from an androgen produces an estrogen.)
Takayasu arteritis (medium - size to large vessels)
Vitamin B 6 (pyridoxine)
Yohimbine

36. What two drugs block dopa - decarboxylase in the periphery to decrease the conversion of L- dopa to dopamine?
Physiologic antagonism
Disulfiram
Fructose; both glucose and galactose are actively absorbed via secondary active transport.
Carbidopa and benserazide

37. Name the most common type or cause - Subacute bacterial endocarditis
CD4+T cells
Streptococcus viridans
VPL nucleus sends its fibers to synapse in the postcentral gyrus of the parietal lobe.
Hemiballismus

38. In What tract does pain - temperature - and crude touch sensory information ascend to the postcentral gyrus of the parietal lobe?
Spinothalamic tract (anterolateral system)
CN VII - IX - and X; taste and general sensation for the tongue is sent to the solitary nucleus.
Renal circulation
Serocystadenoma

39. What are the proteoglycans of cartilage and bone?
Right - sided valves
Chondroitin sulfate and keratan sulfate
P wave
Plasmodium malariae

40. What is the term for the strength of the association between Ags and Abs?
Avidity. There is a positive correlation between valence numbers and avidity.
Impaired ejaculation
Measurement bias
Generalized anxiety disorder

41. What ocular muscle x Elevates and adducts the eyeball?
Constipation and miosis
Superior rectus (CN III) (LR6 SO4)3
With an increased depth of breathing both the total and alveolar ventilation increase. This concept is always tested on the boards - so remember it.
Nerve fibers with small diameter and high firing rates are most sensitive to local blockade

42. Name the Hgb - O2 binding site based on the following information: x Least affinity for O2; requires the highest PO 2 levels for attachment (approx. 100 mm Hg)
Hemiazygous vein
Site 4
NaCl is removed from the lumen to dilute the fluid leaving the loop of Henle.
Accommodation

43. What skin condition has irregular blotchy patches of hyperpigmentation on the face commonly associated with OCP use and pregnancy?
Osteitis fibrosa cystica (von Recklinghausen disease)
Melasma
1. Pinpoint pupils 2. Decreased respiratory rate 3. Coma
Trypsin

44. What statistical test compares the means of groups generated by two nominal variables by using an interval variable?
Hepatitis - with or without necrosis
Metaraminol (a1 - Beta1 )
Two - way ANOVA. It allows the test to check several variables at the same time.
Ethacrynic acid

45. What three factors do Sertoli cells produce for normal male development?
Inhibin - m
Truncus (1) arteriosus Transposition of the (2) great vessels Tri(3)cuspid atresia Tetra(4)logy of Fallot They all begin with T
Third week; they are derived from the wall of the yolk sac.
ACh - histamine - and gastrin

46. What is the size of the prokaryotic ribosome?
70S ribosomes in prokaryotes and 80S ribosomes in eukaryotes
Kawasaki disease
Lung recoil - being a force to collapse the lung - increases as the lung enlarges during inspiration.
Lipid - soluble hormones are considered slow - acting hormones.

47. Name the lung measurement based on the following descriptions: x Volume in the lungs at the end of passive expiration
There are two eukaryotic upstream promoters. The TATA box is -25 base pairs upstream; the CAAT box is -75 bases upstream.
Transference. When it is from the physician to the patient it is called countertransference.
Functional residual capacity (FRC)
Complex I

48. How many NADPHs are used per addition of acetyl CoA into a fatty acid chain?
IgA
2 NADPHs per acetyl CoA
Rifampin
Superficial spreading melanoma

49. What tract is responsible for voluntary refined movements of distal extremities?
Corticospinal tract
The conversion of tyrosine to dopamine in the cytoplasm
Proencephalon diencephalon derivative
Free ionized Ca2+

50. During puberty - What is the main drive for the increased GH secretion?
Nominal scale (categorical - e.g. - male or female)
No. Remember - tests do not diagnose - they confirm or refute your diagnosis. Also - diagnosis of MI requires two of three criteria: chest pain consistent and characteristic of MI - elevated cardiac enzymes consistent with MI - and ST segment elevati
Increased androgen secretion at puberty drives the increased GH secretion.
L2 to L4 (L2 to L4 - thigh; L4 to S3 - leg)