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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. Do the PO2 peripheral chemoreceptors of the carotid body contribute to the normal drive for ventilation?
Burkitt lymphoma
When it crosses the teres major
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.
Increase the concentration of enzymes

2. Name the type of regeneration (i.e. - labile - stable - or permanent) based on the following examples - Smooth muscle
Diverticulosis
Stable
Corynebacterium diphtheriae
Kupffer cells

3. Name the pattern of genetic transmission characterized thus: both M and F affected; no M- to - M transmission; affected M passes trait to all daughters - every generation; affected F passes trait to both sons and daughters; a single mutant allele can
Yellow fever (flavivirus)
Serratus anterior
The lack of glutathione peroxidase activity results in a decrease in NADPH production - leaving glutathione in the reduced state.
X- linked dominant

4. What enzyme is essential for the conversion of CO2 to HCO3-?
robenecid - a uricosuric agent
Central/neurogenic diabetes insipidus; in the nephrogenic form there is sufficient ADH available - but the renal collecting ducts are impermeable to its actions.
1. Big 2. Bilateral 3. Berry aneurysm
Carbonic anhydrase

5. What potent platelet aggregator and vasoconstrictor is synthesized by platelets?
TXA2
Aspiration
Ptosis (eyelid drooping) - miosis (pupillary constriction) - and anhydrosis (lack of sweating) occur when the preganglionic sympathetic fibers from T1- to T4 are obstructed.
Helicase (requires ATP for energy)

6. Do the following structures pick up stain from hematoxylin or eosin? - Nuclei
Parvovirus B-19
Adenocarcinoma (because of Barrett esophagus)
LCO - an index of lung surface area and membrane thickness - is decreased in fibrosis because of increased membrane thickness and decreased in emphysema because of increased surface area without increase in capillary recruitment; in exercise there is
Hematoxylin

7. Name the type of mutation: x New codon specifies for a stop codon
Down syndrome (it is slightly more common than fragile X syndrome.)
Sympathetic chain ganglion
LGB (think EYES)
Nonsense

8. Which IL increases IgA synthesis?
Saccule and utricle
S phase
Leukemias
IL-5. It also stimulates eosinophil proliferation.

9. What determines the effective osmolarity of the ICF and the ECF compartments?
Profound (I.Q. range < 20)
As the isotype is switched - the Ab specificity does not change because it does not affect the variable chains.
The concentration of plasma proteins determines effective osmolarity because capillary membranes are freely permeable to all substances except proteins.
CN VI - VII - and VIII

10. What topoisomerase makes ssDNA cuts - requires no ATP - relaxes supercoils - and acts as the swivel in front of the replication fork?
Topoisomerase I (Relaxase)
Calcium oxalate
Flumazenil
Trisomy 12 (nearly 50% of patients with CLL have abnormal karyotypes.)

11. What nucleus of the hypothalamus receives visual input from the retina and helps set the circadian rhythm?
Large segment deletions
Rheumatic fever
Suprachiasmatic nucleus
The conversion of tyrosine to dopamine in the cytoplasm

12. A unilateral lesion In what nucleus will produce ipsilateral paralysis of the soft palate?
Digoxin is renally eliminated; digitoxin is hepatically eliminated.
Vitamin B 6 (pyridoxine)
Ethambutol
Nucleus ambiguus - resulting in the uvula deviating away from the side of the lesion.

13. Name the most common type or cause - Panhypopituitarism
Glucose and galactose
Pedophilia
Phase I
Sheehan syndrome

14. What component of the cardiovascular system has the largest blood volume? Second largest blood volume?
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.
Stage 3 and 4 most commonly. It can occur at any stage in the sleep cycle and is usually associated with a major stressor being introduced into the home.
The left gastric - splenic - and common hepatic arteries
Graves disease (Increased T4 decreases TRH and TSH through negative feedback.)

15. What is the lecithin:sphingomyelin ratio in respiratory distress syndrome of newborns?
VLDL
Area 17
<2
Frontal lobe

16. In What area of the brain can an excess of dopamine lead to psychotic symptoms?
Temporal lobe
1. H2O2 2. Superoxide 3. Hydroxyl radical 4. Myeloperoxidase 5. Hypochlorous acid
Mesocortical area
Type IV hypersensitivity (cell - mediated)

17. What is the term for the unidirectional attraction of cells toward a chemical mediator released during inflammation?
Area 6
Chemotaxis
Foscarnet
Viscosity and resistance are proportionally related. The greater the viscosity - the greater the resistance is on the vessel.

18. Eating fava beans can produce the Mediterranean type of what deficiency?
G-6- PD deficiency
C5a
Nonsense
Cortisol

19. Name the most common type or cause - Viral pneumonia leading to death
1. Diarrhea 2. Dermatitis 3. Dementia 4. Death
Posterior chamber
Nominal scale (categorical - e.g. - male or female)
RSV

20. What is the rate - limiting step in a conduction of a NMJ?
Superior and anterior
The time it takes ACh to diffuse to the postjunctional membrane
Chromosome 15
Lower lobe

21. What two glycolytic enzymes catalyze the substrate - level phosphorylations?
3- Phosphoglycerate kinase and pyruvate kinase; this produces two ATPs per enzyme (total four ATPs)
1. The child poses an imminent danger to self or others. 2. The child is unable to self - care daily at the appropriate developmental level. 3. The parents or guardians have no control over the child or will not promise to ensure the child's safety e
Hematogenous
The Palmar interosseus ADducts - whereas the Dorsal interosseus ABducts (PAD and DAB)

22. Name the cancer associated with the following oncogenes. (Some may have more than one answer) x cyclin D
Mantle cell lymphoma
In the peroxisome until it is 10 carbons long; the rest is completed in the mitochondria.
Allelic exclusion. It is to ensure that one B cell produces only one Ab.
Theca cells secrete estrogen. After fertilization the theca cells form from the theca interna.

23. Which serotypes of HPV are associated with plantar warts?
HPV serotypes 1 and 4
Plasmodium vivax
Axis I
Projective test. Most tests with a wide range of possibilities for the answers are projective.

24. Do genomic or cDNA libraries contain introns - exons - promoters - enhancers - and are they fragmented?
Tolcapone and entacapone
Glucocorticoids and amphetamines
Diffusion rate is indirectly proportional to membrane thickness and is directly proportional to membranes surface area.
Genomic libraries are made from nuclear DNA - are fragmented - and contain all sequences found in the particular genome copied.

25. What is the most common STD?
HPV
HBeAg
Monocytosis
Anterior limb of the internal capsule is supplied by the anterior cerebral artery.

26. Does physiologic splitting of the first heart sound occur during inspiration or expiration? Why?
Clostridium perfringens
Splitting of the first heart sound occurs during inspiration because of the increased output of the right ventricle - delaying the closure of the pulmonic valve.
Tyrosine
Streptococcus pyogenes

27. What are the two ketogenic AAs?
G-6- PD deficiency; pyruvate kinase deficiency is second.
Leucine and lysine
Breast
LARP: Left goes Anterior and Right goes Posterior (because of the rotation of the gut; remember your embryology!)

28. What sensory system is affected in the late spinal cord manifestation of syphilis?
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.
RU 486
Phosphorylation of mannose residues
Bipolar disorder (manic - depressive disorder)

29. What has occurred to the renal arterioles based on the following changes in the GFR - RPF - FF - and glomerular capillary pressure? - GFR ? - RPF ? - FF ? - capillary pressure ?
pH of 2 and 9
Selegiline
Hypermyelination of the corpus striatum and the thalamus (seen in cerebral palsy)
Constriction of efferent arteriole

30. What muscle or muscles are innervated by the following nerves? - Long thoracic nerve
A high - resistance system is formed when resistors are added in a series.
Serratus anterior
Bell pad
The deepest sleep levels (stage 3 and 4) occur mostly in the first half of sleep.

31. What enzyme catalyzes the rate - limiting step in cholesterol metabolism?
Ventricular fibrillation (V fib)
Rheumatoid arthritis
HMG- CoA reductase
RBCs

32. The increased oxygen consumption after phagocytosis is for...
Dimercaprol - D- penicillamine
1. CNS 2. Renal tubules 3. Beta Islet cells of the pancreas 4. RBCs 5. GI mucosa
ATP production
1. Maltose 2. Maltotetrose 3. a - Limit dextrans (a -1 - 6 binding)

33. What structure of the knee is described thus? - Prevents adduction
ater flows from a low - solute to high - solute concentrations.
Decreases
Mitral insufficiency
Lateral collateral ligament

34. What ocular muscle x Depresses and abducts the eyeball?
Schedule dependent; antineoplastic agents that work on nonproliferating cells are dose dependent
Superior Oblique (CN IV) (LR6 SO4)3
Atracurium
Projective drawing. The artistic form is irrelevant - but the size - placement - erasures - and distortions are relevant.

35. Name the most common type or cause - Meningitis in renal transplantation patients
Axillary nerve and posterior humeral artery
Listeria monocytogenes
IgA
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

36. Multiple pregnancies - early age of intercourse - multiple sexual partners - OCP use - smoking - HIV - and STDs.
apo B-48
Risk factors for cervical cancer
Basophilic stippling
Heart - esophagus - and colon. Remember - you get megas: cardiomegaly - megaesophagus - and megacolon.

37. Are the following major or minor Jones criteria of rheumatic fever? - Pericarditis
Motor nucleus of CN V
Major
Alcohol consumption
H1 histones

38. Name the T- cell CD marker: x Essential for Ab isotype switching (for B cell binding)
VLDL
Pernicious anemia
Urinary 17- ketosteroids
CD40 ligand

39. What part of the heart forms x Superior border?
Conus arteriosus of the right ventricle and right and left auricles
Ewing sarcoma
Entamoeba histolytica
Hairy cell leukemia

40. What is the most common one? - Cardiac tumor
refuse
Left atrial myxoma
With opioid use the pupils become pinpoint (miosis) because of increased cholinergic activity.
Fluconazole

41. Name these cluster A personality disorders: x Baseline mistrust; carries grudges; afraid to open up; uses projection as defense mechanism; lacks hallucinations or delusions
Y - W-135 - and C and A capsular polysaccharides
Paranoid
G-6- PD deficiency
EF- Tu and EF- Ts of the 30S ribosomal subunit

42. Projectile nonbilious vomiting and a small knot at the right costal margin (olive sign) are hallmarks of What embryonic disorder?
Outside the cell
Hypertrophic pyloric stenosis due to hypertrophy of the muscularis externa - resulting in a narrowed pyloric outlet
The first trimester
NADPH - O2 - and cytochrome b5

43. What phase of Food and Drug Administration approval tests x The safety in healthy volunteers?
Ampulla
Alveoli; they are part of the respiratory portion.
Hirschsprung's disease (colonic gangliosus)
Phase I

44. What malignant bone tumor is associated with familial retinoblastoma?
Hematogenous
Osteosarcoma
VLDLs
Brucella and Listeria (has tumbling motility)

45. Which nicotinic receptor antagonist is inactivated to laudanosine?
Ipratropium
Cystic fibrosis
Atracurium
S phase

46. Name the antimicrobial agent whose major side effect is listed - Grey baby syndrome
Hypospadia
Chloramphenicol
Clozapine
Opsonization

47. What type of mortality rate is defined as the number of deaths x From a specific cause per all deaths?
Lithium
Ascorbic acid (vitamin C) deficiency (These are the signs of scurvy.)
Truncus arteriosus
Proportionate mortality rate

48. What nerve and artery could be affected in a midshaft humeral fracture?
Diffusion rate is indirectly proportional to membrane thickness and is directly proportional to membranes surface area.
Chromosome 15
The renal circulation has the smallest AV O2 (high venous PO2) difference in the body because of the overperfusion of the kidneys resulting from filtration.
Radial nerve and the profunda brachii artery

49. What are the three microscopic pathologic changes seen in Alzheimer's disease?
Dendritic cells - macrophages - and thymic epithelial cells
Transcortical apraxia; Wernicke's area of the left hemisphere cannot communicate with the right primary motor cortex because of the lesion in the corpus callosum.
Senile plaques - neurofibrillary tangles - and granulovascular changes in neurons
Mast cells

50. When does the hydrostatic pressure in Bowman's capsule play a role in opposing filtration?
Parietal lobe
It normally does not play a role in filtration but becomes important when there is an obstruction downstream.
Duodenal atresia
Type III hypersensitivity reaction