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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 two bacteria are associated with drinking unpasteurized milk?
Brucella and Listeria (has tumbling motility)
Amphotericin B
Hemophilia B
Gonads

2. What is associated with prolonged lithium use?
Ischemic
Hypothyroidism. (TSH levels must be monitored.)
The number of cross - bridges cycling during contraction: the greater the number - the greater the force of contraction.
NO!! Remember - only a judge can commit a patient. A physician can detain a patient (maximum is for 48 hours).

3. Increased urinary excretion of what substance is used to detect excess bone demineralization?
Polycythemia vera (Remember - polycythemia vera is a risk factor for acute leukemias.)
ydroxyproline
Metabolic alkalosis (summary: high pH - low H+ and high HCO3-)
T3 increases both heart rate and cardiac output by increasing the number of Beta - receptors and their sensitivity to catecholamines.

4. What cell's axons are the only ones that leave the cerebellar cortex?
The Purkinje cell
TTP; thrombocytopenia with megathrombocytes is more characteristic of ITP.
0.21; it is a fancy way of saying 21% of the air is O2.
Roth spots - and they are seen in bacterial endocarditis.

5. What is the term for the point on a scale that divides the population into two equal parts?
Median (think of it as the halfway point)
Chlamydia
Prefrontal cortex; it is in front of the premotor area.
CN XII

6. What do the following values indicate? - LD50
Primary hypercortisolism
1. Decrease the radius of the vessel 2. Increase the length of the vessel 3. Increase the viscosity 4. Decrease the number of parallel channels
Biotin - ATP - and CO2
Lethal dose for 50% of drug takers (median lethal dose)

7. What is the name of the force that develops in the wall of the lungs as they expand?
Primary polydipsia; patients with diabetes insipidus will continue to produce large volumes of dilute urine.
Lung recoil - being a force to collapse the lung - increases as the lung enlarges during inspiration.
Vibrio vulnificus
Borrelia recurrentis

8. Name the antimicrobial agent whose major side effect is listed - Teratogenicity
Male pseudo - intersexuality (hermaphrodite); these individuals are 46XY.
The submandibular ganglion. (Submandibular ganglion innervates the submandibular gland; easy enough.)
Metronidazole
More Ab is produced in less time in a secondary immune response (shorter lag period).

9. What enzyme is deficient in alkaptonuria?
Klebsiella pneumoniae
Positive
By causing rebound insomnia and decrease in REM sleep
Homogentisic oxidase

10. How can a genetic deficiency of carbamoyl phosphate synthetase be differentiated from an ornithine transcarbamoylase deficiency?
The vermis
Phase 2
CD3 molecule. It transmits signals to the inside of the T cell to trigger activation
Uracil and orotic acid levels increase with ornithine transcarbamoylase deficiency and are normal in carbamoyl phosphate synthetase deficiency.

11. In which quadrant is breast cancer most commonly found?
Cardiac muscle
McArdle's syndrome
Upper outer quadrant (left more than right)
Phosphofructokinase -1 and costs 1 ATP

12. What AA undergoes N- glycosylation?
Paradoxic emboli most commonly enter the arteries through a patent septal defect in the heart.
Motor aspect
Asparagine
Follicular lymphoma

13. What form of penicillin is stable in acid environments?
Immature B cells
Ea (activation energy)
Specific rate (e.g. - men aged 55-60)
Penicillin V

14. Does light or darkness regulate the pineal gland?
Blocking
Light regulates the activity of the pineal gland via the retinal - suprachiasmatic - pineal pathway.
Specificity (it deals with the healthy)
Melasma

15. What is the formula to calculate IQ?
(MA/CA) x 100 = IQ score - where MA = mental age and CA = chronological age
Four
Absolutely not. Diabetics who are given a Beta- blocker for an acute chest syndrome have significantly better outcomes than those who do not.
ACE inhibitors (the - pril agents)

16. What operant conditioning therapy or modification is described as x Removing a reinforcement (without the patient knowing) gradually over time to stop a condition?
Dihydropteroate synthetase
SITS
Pseudomonas aeruginosa
Fading

17. What is the most common one? - Primary malignant tumor of the female genital tract in the United States
1. CHF 2. Vena caval obstruction or constriction 3. Hepatic cirrhosis 4. Renal artery stenosis
Adenocarcinoma of the cervix
CN V
Flumazenil

18. 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?
Coxiella burnetii
Down syndrome (trisomy 21)
Palms and soles of the feet. Sebaceous glands are associated with hair follicles - which are lacking on the palms and soles of the feet.
Plasmin

19. Has very little effect on arteriolar dilation or constriction.
Intrinsic factor (IF)
Dynorphin
The parasympathetic nervous system
Superior and posterior

20. What CN nucleus receives auditory information from both ears via the cochlear nuclei?
1. Posterior auricular vein 2. Posterior division of the retromandibular vein
UMP
Allopurinol
Superior olivary nucleus

21. What term is an index of the effort needed to expand the lungs (i.e. - overcomes recoil)?
Cryptococcus neoformans
Compliance; the more compliant a lung is - the easier it is to inflate.
Jejunum (upper)
Lac repressor protein

22. What hormone disorder is characterized by the following abnormalities in sex steroids? - LH? - and FSH?? - Sex steroids - LH - FSH
The increased H+ moves intracellularly and is buffered by K+ leaving the cells - resulting in intracellular depletion and serum excess. (Intracellular hypokalemia is the reason you supplement potassium in diabetic ketoacidosis - even though the serum
Pituitary hypogonadism
Central sulcus (sulcus of Rolando)
CD40

23. What happens to diastolic and systolic intervals with an increase in sympathetic activity?
Onset of bleeding
Systolic interval decreases secondary to increased contractility; diastolic interval decreases secondary to an increase in heart rate.
Good Samaritan Law. (Physicians are not required to stop and help.)
At 8 to 9 years of age. Prior to this age they view death as a form of punishment.

24. What endocrine abnormality is characterized by the following changes in PTH - Ca2+ - and inorganic phosphate (Pi)? - PTH decreased - Ca2+ decreased - Pi increased
At the end of the PCT 25% of the original volume is left
CD16 and CD56
Primary hypoparathyroidism
Methionine (start) and tryptophan are the only two AAs with only one codon.

25. What is the only encapsulated fungal pathogen?
Enterohemorhagic Escherichia coli
Cholera toxin irreversibly activates the cAMP- dependent chloride pumps of the small and large intestine - producing a large volume of chloride - rich diarrhea.
Trichuris trichiura is treated with albendazole.
Cryptococcus

26. Name the most common type or cause - Sudden cardiac death
Flocculonodular lobe (one of my favorite words in all of medicine!)
Barrett esophagus has an increased risk of developing adenocarcinoma of the esophagus.
Ventricular fibrillation (V fib)
Entamoeba histolytica

27. What is the most common lethal AR disorder affecting white Americans?
Liver (hepatocytes)
Ungated potassium channel
Cystic fibrosis
Stylopharyngeus muscle is innervated by CN IX; all other pharyngeal muscles are innervated by CN X.

28. What is the most common organ involved in amyloidosis?
Kidney
Chief cells
Posterior cruciate ligament
Melanocytes

29. What are the four characteristics of all protein - mediated transportation?
Isolation of affect
Teratoma (dermoid cyst)
Barrett esophagus has an increased risk of developing adenocarcinoma of the esophagus.
1. Competition for carrier with similar chemical substances 2. Chemical specificity needed for transportation 3. Zero - order saturation kinetics (Transportation is maximal when all transporters are saturated.) 4. Rate of transportation faster than i

30. Clarke's nucleus is the second ascending sensory neuron of which spinocerebellar tract?
Short - chain fatty acids
Bilateral degeneration of the dorsal columns in the spinal cord secondary to syphilis is known as tabes dorsalis. A high - step gait is seen in patients with tabes dorsalis because of the inability to feel the ground beneath their feet.
Dorsal spinocerebellar tract; the accessory cuneate nucleus is the second nucleus for the cuneocerebellar tract.
When the pH is more acidic than the pI - it has a net positive charge - and when the pH is more basic than the pI - it has a net negative charge.

31. Which sodium channel blocker is used to treat lithium - induced diabetes insipidus?
Stimulus generalization must stop. (Pairing of the unconditioned stimulus and the conditioned stimulus must cease.)
1. Liver 2. Muscle 3. Adipose tissue
Postductal coarctation of the aorta (adult)
Amiloride

32. What is the term for hypoperfusion of an area involving only the inner layers?
CD16 and CD56
With arteriolar constriction both the flow and pressure downstream decrease.
Bronchogenic carcinoma
Mural infarct

33. What rate is indicated by 1- specificity?
False - positive rate
Yes
Indirect pathway (Tourette syndrome for example)
Basal cell carcinoma

34. Where is most of the airway resistance in the respiratory system?
Scavenger receptor (SR- B1)
Stable
In the first and second bronchi
Cilia

35. What is the most common disease or infection reported to the CDC?
Receptive aphasia is due to a lesion in Brodmann areas 22 - 39 - and 40; generally the patient is unaware of the deficit.
CN X
Sphingomyelinase
Chlamydia; gonorrhea is second (Remember - it is mandatory to report STDs to the CDC.)

36. What syndrome is characterized by sweating - insomnia - nausea - diarrhea - cramps - delirium - and general restlessness secondary to MAOI and SSRI in combination?
Granulosa/thecal cell tumor of the ovary
Serotonin syndrome. It is also associated with high doses and MAOI and synthetic narcotic combinations (Ecstasy). Treatment consists of decreasing SSRI dosage - removing the causative agent - and giving cyproheptadine.
Vitreous humor
Hallucinations are sensory impressions (without a stimulus); illusions are misperceptions of real stimuli; and delusions are false beliefs that are not shared by the culture.

37. What is the only pharyngeal muscle not innervated by CN X?
Catechol - O- methyl transferase (COMT)
Stylopharyngeus muscle is innervated by CN IX; all other pharyngeal muscles are innervated by CN X.
Cricothyroid muscle; all other laryngeal muscles are innervated by the recurrent laryngeal nerve.
In the tuberoinfundibular pathway - dopamine release will decrease prolactin release - Which is why dopamine agonists are used in the treaatment of hyperprolactinemic states.

38. Name the phase of the eukaryotic cell cycle: x Period of cellular growth (translation and transcription) before DNA synthesis
Gaucher disease
Dihydropteroate synthetase
G1 phase (gap 1)
Methicillin

39. What enzyme catalyzes the rate - limiting step in heme synthesis?
Chorda tympani of CN VII
Thiabendazole
Conjugated (direct) hyperbilirubinemia - a transport defect
d - ALA synthase

40. Which gram - negative diplococcus grows on chocolate agar? Thayer - Martin medium?
7
Meningococcus grows on chocolate agar - and Gonococcus grows on Thayer - Martin medium.
Norm reference (i.e. - 75% of the students in the class will pass)
gamma and delta chains

41. What two areas of the skin do not contain sebaceous glands?
Palms and soles of the feet. Sebaceous glands are associated with hair follicles - which are lacking on the palms and soles of the feet.
Ampulla of the fallopian tube
Excess lead
Ungated potassium channel

42. What bile pigment is formed by the metabolism of bilirubin by intestinal bacteria - giving stool its brown color?
Stercobilin
The inner cortex (paracortex) contains the T cells - so it is considered the thymic - dependent area.
Vascular dementia. It is characterized as a stepwise deterioration in cognitive function.
Marfan syndrome

43. Is derived from the ventral wall of the foregut.
The respiratory system
Wilson disease
Guanethidine and bretylium
Burkitt lymphoma

44. What is the most common one? - Form of vasculitis
Bone deposition increases with increased Ca2+ or PO 4- concentrations - whereas resorption (breakdown) is increased when there are low levels of Ca2+ or PO4-.
Temporal arteritis
1. Streptomycin 2. Gentamicin 3. Tobramycin
Smooth muscle

45. What condition results from a deficiency in the enzyme hexosaminidase A?
Tay- Sachs disease
Formal operations (> 12 years)
Aromatase
Axis IV

46. What is the most common form of elderly abuse?
Negative selection. This helps to prevent autoimmune diseases.
Nearly 50% of all reported cases of elderly abuse are due to neglect. Physical - psychological - and financial are other forms of elderly abuse with an overall prevalence rate of 5% to 10%.
Stratum granulosum
With an increased rate of breathing the total ventilation is greater than the alveolar ventilation. Rapid - shallow breathing increases dead space ventilation with little change in alveolar ventilation. (This is hypoventilation).

47. What malignant tumor of the skin is associated with Birbeck granules?
Acetyl CoA - FADH2 - and NADH
Histiocytosis X
1. Skin 2. Liver 3. Kidney
>10 mm

48. What organelles make ATP - have their own dsDNA - and can synthesize protein?
Adult tapeworms develop in the definitive host - whereas cysticerci or larvae develop in the intermediate host.
Stercobilin
A gene (a rather simple definition but accurate)
Mitochondria

49. What is the term for the number of individuals who have an attribute or disease at a particular point in time?
Isoleucine - leucine - and valine
Ependymoma
Basal cell carcinoma
Prevalence rate

50. What is the most common one? - Organ involved in amyloidosis
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.
Wiskott - Aldrich syndrome
Macula densa
Kidney