USMLE USMLE Certifications USMLE-STEP-2 Questions & Answers

• Question 341:

  For the screening tests listed below, select the screening schedule that is appropriate for women (as per the U.S. Preventive Services Task Force [USPSTF], The Guide to Clinical Preventive Services, 2006) Fecal occult blood testing (FOBT)

  A. do not routinely screen

  B. yearly over age 50

  C. at first prenatal visit

  D. every 12 years at age 40 and older

  E. every 12 years at age 50 and older

  F. every 3 years following an initial examination, but not after age 65

  G. every 3 years at age 50 and older

  Correct Answer: E

  The USPSTF strongly recommends that men and women aged 50 or older be screened for colorectal cancer. Various methods exist for screening and the optimal interval for screening varies based on the method of screening. Current options for screening average risk individuals include FOBT every 12 years, sigmoidoscopy every 5 years, colonoscopy every 10 years, and other tests. Higher-risk individuals, those with a first-degree relative with a diagnosis of colon cancer before age 60, should receive screening at an earlier age and at shorter intervals.

• Question 342:

  For the screening tests listed below, select the screening schedule that is appropriate for women (as per the U.S. Preventive Services Task Force [USPSTF], The Guide to Clinical Preventive Services, 2006) Cervical cytology (Pap smear)

  A. do not routinely screen

  B. yearly over age 50

  C. at first prenatal visit

  D. every 12 years at age 40 and older

  E. every 12 years at age 50 and older

  F. every 3 years following an initial examination, but not after age 65

  G. every 3 years at age 50 and older

  Correct Answer: F

  The USPSTF strongly recommends screening for cervical cancer (Pap smear) at least every 3 years in women who have been sexually active or are 21 years old, and have a cervix. It recommends against screening after a normal hysterectomy, or after age 65, if recent Pap smears were normal and the woman is not at high risk. (Note: Although evidence is still considered insufficient, screening for human papilloma virus [HPV] infection shows promise as a part of cervical cancer prevention. Vaccination against HPV is expected to greatly decrease the incidence of cervical cancer in the future.)

• Question 343:

  For the screening tests listed below, select the screening schedule that is appropriate for women (as per the U.S. Preventive Services Task Force [USPSTF], The Guide to Clinical Preventive Services, 2006)

  Mammography with or without clinical breast examination

  A. do not routinely screen

  B. yearly over age 50

  C. at first prenatal visit

  D. every 12 years at age 40 and older

  E. every 12 years at age 50 and older

  F. every 3 years following an initial examination, but not after age 65

  G. every 3 years at age 50 and older

  Correct Answer: D

  The USPSTF recommends that women aged 40 and older have screening mammography with or without clinical breast examination, every 12 years.

• Question 344:

  For each of the following scenarios, select the gas exposure responsible for the signs and symptoms.

  Aworker drilling for oil experiences acute tearing, mucous membrane irritation, and onset of a cough while repairing machinery.

  A. carbon monoxide

  B. methane

  C. hydrogen sulfide

  D. ozone

  E. sulfur dioxide

  Correct Answer: E

  Sulfur dioxide is a colorless, pungent gas encountered in drilling for oil, paper production, treatment of fruit, and other processes. Sulfur dioxide is an irritant gas. It causes tearing, mucous membrane irritation, cough, and eventually pulmonary edema. In asthmatics it provokes bronchospasm at low doses. Like other irritant gases, in large quantities, it will damage alveoli and capillary endothelial cells.

• Question 345:

  For each of the following scenarios, select the gas exposure responsible for the signs and symptoms. A garage worker turns on the ventilation system in the winter time while testing a motor, and now complains of a headache and vertigo

  A. carbon monoxide

  B. methane

  C. hydrogen sulfide

  D. ozone

  E. sulfur dioxide

  Correct Answer: C

  Carbon monoxide is an odorless, colorless, tasteless gas produced by partial combustion of tobacco and fuels. The amounts produced by cigarette smoking are not insignificant. The gas combines with hemoglobin preferentially to form carboxyhemoglobin, which makes the patient appear pink. This diminishes the oxygen-carrying capacity of the blood. The resulting anoxia is the major hazard. The onset of symptoms is insidious. Individuals exposed to carbon monoxide may not voluntarily take the action necessary to remove themselves from the toxic fumes

• Question 346:

  For each of the following scenarios, select the gas exposure responsible for the signs and symptoms.

  A man has been pulled unconscious from a mine. No odors are noted, but an experienced miner says there was coal damp in the mine.

  A. carbon monoxide

  B. methane

  C. hydrogen sulfide

  D. ozone

  E. sulfur dioxide

  Correct Answer: B

  Methane is a colorless, odorless, flammable gas sometimes encountered in mines and wells. Methane (coal damp) is a frequent cause of death in inadequately ventilated mines and wells. It acts as an asphyxiant as well as being explosive. Miners used to take caged animals, especially birds, with them. The birds succumbed to the asphyxiants (methane and carbon dioxide) sooner than humans.

• Question 347:

  For each of the following scenarios, select the gas exposure responsible for the signs and symptoms.

  A sewer worker has acute onset of nausea, headache, and shortness of breath, and has anosmia.

  A. carbon monoxide

  B. methane

  C. hydrogen sulfide

  D. ozone

  E. sulfur dioxide

  Correct Answer: C

  Hydrogen sulfide is a colorless gas that rapidly paralyzes the nasal receptors, and is found in sewers. Hydrogen sulfide produces nausea, headache, and shortness of breath. Because it paralyzes the nasal receptors at a concentration of 150 ppm and cannot be smelled shortly after exposure, it is highly dangerous, with instant death from a concentration as low as 1000 ppm.

• Question 348:

  For each of the following scenarios, select the gas exposure responsible for the signs and symptoms. A patient working with an electric arc noted a pungent odor, and now has signs of asthma or early pulmonary edema.

  A. carbon monoxide

  B. methane

  C. hydrogen sulfide

  D. ozone

  E. sulfur dioxide

  Correct Answer: D

  Ozone is a colorless, pungent gas occurring naturally in the stratosphere, which can be produced by electric arcs. Ozone is generated by electrical storms and UV light and electric arcs and some forms of fuel combustion. In the stratosphere, it is protective by blocking solar radiation. At 10 ppm, it can cause pulmonary edema and tracheal pain and is believed to cause asthma. Based on animal tests and observations of gases trapped during inversions, an action level of 10 ppm has been set for work-place exposure.

• Question 349:

  Several groups of organic compounds are associated with serious toxic effects when used in the manufacture of textiles and materials; often found in manufactured homes

  A. nitrosamines

  B. epoxy compounds

  C. PCBs

  D. formaldehydes

  E. organophosphorus compounds

  Correct Answer: D

  Formaldehyde commercial solutions contain up to 15% methanol. Formaldehyde has numerous industrial applications including, use as a base for urea formaldehyde resins. The gas is an irritant to the eyes and upper respiratory mucosa. The odors of products manufactured with formaldehyde products have been responsible for actions against manufacturers of tightly built manufactured homes.

• Question 350:

  Several groups of organic compounds are associated with serious toxic effects when used in the production of resins, plasticizers, and solvents

  A. nitrosamines

  B. epoxy compounds

  C. PCBs

  D. formaldehydes

  E. organophosphorus compounds

  Correct Answer: B

  Epoxy compounds are used in the production of resins. They cause irritation of the skin and mucosa and have caused acute pulmonary edema