A 57-year-old man comes to the office due to unrefreshing sleep.  He feels tired during the day and occasionally has to nap during his lunch hours.  According to his wife, the patient snores loudly during sleep and frequently gasps for breath.  He also has severe claustrophobia.  Past medical history is significant for hypertension.  The patient takes no sedative medications and is a lifetime nonsmoker.  Blood pressure is 156/94 mm Hg and BMI is 30 kg/m².  Physical examination is significant for a bulky tongue and crowded, narrow oropharynx.  Electrical stimulation of which of the following nerves may improve the pathophysiologic cause of this patient’s symptoms?

A 64-year-old man is brought to the emergency department after a motor vehicle collision in which his chest hit the steering wheel.  The patient has no prior medical conditions and takes no medications.  Temperature is 36.7 C (98 F), blood pressure is 132/78 mm Hg, pulse is 76/min, and respirations are 14/min.  Physical examination shows mild tenderness over the lower right chest.  Imaging of the neck and chest reveals no fractures or dislocations.  However, the chest CT scan reveals pleural opacities as shown below.

These abnormal findings are most likely to occur in a patient with which of the following occupational histories?

A 36-year-old man comes to the office due to chronic, mild dyspnea and fatigue.  The patient also says that his mind seems “foggy” all the time and he is not able to think clearly.  He has no significant past medical history and does not take any medication.  He lives a sedentary lifestyle and has smoked a half-pack of cigarettes a day for 5 years.  Blood pressure is 140/85 mm Hg, pulse is 84/min, and respirations are 18/min.  BMI is 32 kg/m².  Lung auscultation is unremarkable.  Chest x-ray is normal.  Arterial blood gas analysis shows partial pressure of oxygen (PaO₂) is 66 mm Hg and partial pressure of carbon dioxide (PaCO₂) is 58 mm Hg.  His estimated alveolar to arterial oxygen gradient is 10 mm Hg.  Which of the following best explains this patient’s laboratory findings?

A 58-year-old man comes to the office due to exertional dyspnea and cough.  His symptoms started 6 months ago and have progressively worsened.  Other medical conditions include recurrent pyelonephritis, peptic ulcer disease, and rheumatoid arthritis.  The patient had taken a medication for rheumatoid arthritis for many years but stopped a year ago, as the drug failed to improve his worsening hand arthritis.  He does not use tobacco, alcohol, or illicit drugs.  Physical examination shows joint disease consistent with rheumatoid arthritis.  Chest x-ray is shown in the image below.

Which of the following is the most likely explanation for this patient’s pulmonary symptoms?

A 35-year-old woman comes to the emergency department due to fatigue, exertional dyspnea, and cough.  She has had subjective fevers but no upper respiratory symptoms, and no family members have had a similar illness.  Medical history is unremarkable, and the patient does not use tobacco.  Temperature is 37.5 C (99.5 F), blood pressure is 118/75 mm Hg, pulse is 90/min, and respirations are 22/min.  Pulmonary examination shows normal air exchange with scattered crackles and no wheezes.  The patient also has nontender cervical lymphadenopathy.  Serum chemistry shows a calcium level of 12.0 mg/dL.  Chest x-ray demonstrates scattered nodules and parenchymal infiltrates, as shown in the image below.

Lymph node biopsy reveals noncaseating granulomas.  Which of the following is the most likely cause of the elevated calcium level in this patient?

A 64-year-old man comes to the office due to 4 weeks of progressive dyspnea.  For the past several months, he has had a nonproductive cough and fatigue.  The patient’s medical conditions include degenerative joint disease and peptic ulcer disease.  He smoked 2 packs of cigarettes daily for 38 years but quit 4 years ago.  On examination, there are decreased breath sounds and percussive dullness at the base of the right lung.  Chest CT scan reveals a right-sided pleural effusion and diffuse nodular thickening of the pleura.  On thoracentesis, bloody fluid is obtained.  Pleural biopsy shows proliferation of epithelioid-type cells that are joined by desmosomes, contain abundant tonofilaments, and are studded with very long microvilli.  Which of the following is the most likely diagnosis?

A 64-year-old man is evaluated for worsening cough and shortness of breath.  The patient has a history of hypertension and type 2 diabetes mellitus.  He smokes a pack of cigarettes daily and drinks alcohol occasionally.  Temperature is 38 C (100.4 F), blood pressure is 140/82 mm Hg, and pulse is 92/min.  Lung auscultation reveals abnormal breath sounds.  Chest x-ray is shown below.

Which of the following is the most likely cause of the observed pulmonary findings in this patient?

A 42-year-old woman comes to the office due to several months of episodic shortness of breath and cough.  The patient has a history of migraines and occasionally takes acetaminophen.  She is a school teacher and does not use tobacco, alcohol, or illicit drugs.  Temperature is 36.1 C (97 F), blood pressure is 110/80 mm Hg, and pulse is 84/min.  Pulse oximetry shows 96% on room air.  Lung examination and chest x-ray are normal.  Spirometry shows that FEV1 is 71% of the predicted value.  Sputum analysis shows predominant eosinophils.  Exposure to which of the following is most closely associated with this patient’s symptoms?

A 29-year-old African American woman is being evaluated for exertional dyspnea and dry cough. She has no significant medical history and takes no medications. The patient works part-time as a bird keeper at a zoo. Chest x-ray reveals bilateral hilar adenopathy and reticular pulmonary infiltrates. Serum ACE levels and calcium levels are elevated. Purified protein derivative testing is negative. A bronchoscopy is scheduled to help determine the diagnosis. Which of the following is most likely to be the predominant cell type in this patient’s bronchoalveolar lavage fluid?

A 64-year-old man is brought to the emergency department due to worsening shortness of breath.  The patient is able to speak in short sentences only and becomes hypoxemic with minimal exertion.  His medical history includes hypertension and dyslipidemia.  He smoked a pack of cigarettes a day for 40 years and worked for 25 years as a nickel miner.  His father died of chronic respiratory failure.  While in the emergency department, he rapidly develops respiratory failure and is intubated.  Despite appropriate treatment, he dies several days later in the intensive care unit.  Autopsy is performed, and examination of the bronchi reveals thickened bronchial walls, inflammatory infiltrates, mucous gland enlargement, and patchy squamous metaplasia of the bronchial mucosa.  Which of the following factors was likely the greatest contributor to this patient’s pathological findings?

A 35-year-old woman, gravida 1, para 0, at 12 weeks gestation comes to the office for evaluation of genital warts.  She first noticed the warts last week and is concerned that it has persisted.  The patient has occasional mild pruritus but no pain.  She is currently sexually active with her boyfriend and engages in oral and vaginal intercourse.  Examination shows several verrucous, skin-colored lesions over the labia majora.  The patient asks whether the lesion could affect her future child.  The virus involved in this patient’s condition also has an affinity to infect which of the following structures?

A 27-year-old man comes to the physician with his wife for an infertility evaluation.  They have been trying to conceive for the last 14 months without success.  A semen analysis shows a normal sperm count but completely immobile sperm due to abnormal tail function.  Which of the following additional findings is most likely associated with this patient’s condition?

A 45-year-old man is evaluated for persistent cough and progressive dyspnea on exertion.  The patient has no medical issues but has been exposed to large quantities of coal dust while working as a miner for the past 15 years.  Chest imaging reveals small, nodular opacities in the upper lobes.  Lung biopsy shows fine carbon particles within the patient’s respiratory bronchioles and alveolar ducts.  Which of the following mechanisms is most directly responsible for clearing the foreign particles from this patient’s respiratory tract?

A 55-year-old woman comes to the office due to a persistent cough, exertional dyspnea, and recent, unintentional weight loss.  She has no chronic medical problems and takes no medication regularly.  She has never smoked and has no history of exposure to industrial pollutants.  She works as an accountant at a large accounting firm.  Vital signs are normal.  Physical examination reveals decreased breath sounds and dullness to percussion at the left lung base.  Imaging studies show an irregular mass in the lower lobe of the left lung and a left pleural effusion.  A diagnostic thoracocentesis is performed and the aspirated fluid is sent for cytological evaluation.  If a malignancy is diagnosed, it is most likely to be which of the following types?

A 64-year-old man is being evaluated due to nagging right shoulder pain that radiates to the ipsilateral arm.  The patient also has weakness in the right upper extremity.  Symptoms started 2 months ago and have progressively worsened.  He has a 40-pack-year smoking history.  On neurologic examination, the patient is awake, alert, and oriented and follows commands.  He has partial right-sided ptosis with fully intact extraocular movements.  The pupils are asymmetric in dim light with 2 mm on the right and 4 mm on the left, but both are reactive to light.  The pupils become more symmetric in bright light.  The right upper extremity has 3/5 strength and absent deep tendon reflexes.  This patient’s autonomic dysfunction is most likely caused by injury to which of the following structures?

Molecular biologists studying the properties of hemoglobin are investigating the structural changes associated with oxygen loading and unloading.  During the transition from point 1 to point 2 on the graph shown below, hemoglobin molecules are most likely to release which of the following?

A 13-year-old girl is undergoing hematologic evaluation.  She is found to have a hemoglobin mutation that changes the partial pressure of oxygen at which hemoglobin is 50% saturated to 20 mm Hg.  In comparison, normal hemoglobin becomes 50% saturated with oxygen at 26 mm Hg.  Which of the following sequelae is this patient most likely to develop as a result of her mutation?

A 43-year-old man comes to the office due to occasional dyspnea that awakens him at night.  This symptom started approximately a year ago after a severe upper respiratory tract infection, and since then he has also had an episodic cough.  The patient has no other medical problems and takes no medications.  He has no drug allergies and does not use tobacco, alcohol, or illicit drugs.  His older brother has atopic dermatitis.  Vital signs are normal.  Lung auscultation reveals bilateral normal breath sounds with no wheezing or crackles.  Heart sounds are normal, and there is no extremity edema.  Pulmonary function tests are as follows:

Administration of which of the following medications would be most useful during further diagnostic evaluation of this patient?

A 27-year-old woman comes to the office due to exertional dyspnea over the past 3 months.  The patient initially had shortness of breath during exercise but now becomes dyspneic with routine activities.  She has had no cough, fever, or leg swelling but has noticed increased fatigue over this time.  The patient does not use tobacco, alcohol, or illicit drugs.  Vital signs are within normal limits.  Physical examination reveals a loud pulmonic component of S2 but is otherwise unremarkable.  Chest x-ray is normal.  Echocardiography shows elevated pulmonary artery systolic pressure and right ventricular hypertrophy.  Left ventricular structure and function are normal.  Which of the following patterns of chemical mediators is most likely present in this patient’s pulmonary arteries?

A 42-year-old man comes to the emergency department due to several hours of dyspnea.  He is a long-haul truck driver who became acutely short of breath during a 36-hour trip but previously had been healthy.  The patient smokes a pack of cigarettes daily and drinks a 6-pack of beer on weekends.  Pulmonary examination reveals vesicular breath sounds bilaterally with the overlying areas resonant to percussion.  CT pulmonary angiogram shows a right lower lobe pulmonary artery occlusion consistent with pulmonary embolism but no evidence of pulmonary infarction.  Which of the following is the most likely reason for the lack of lung tissue necrosis in this patient?

A 48-year-old man comes to the office for an initial visit.  He says that he feels well and has no known medical conditions.  The patient has a 20-pack-year smoking history and does not use alcohol or recreational drugs.  He is counseled on smoking cessation.  During the discussion of how smoking affects lung function, the patient is shown a graph of the expected change in forced expiratory volume in 1 second (FEV₁) over time if he continues to smoke at the same rate (Curve D shown below).  Which of the following curves most likely demonstrates the expected FEV₁ over time if this patient were to stop smoking now?

A 54-year-old man comes to the office due to daytime sleepiness and lack of energy.  The symptoms began 6 months ago and have progressively worsened so that he feels “completely drained” by the end of the day.  The patient’s wife mentions that he snores loudly.  His past medical history is unremarkable, although he has not seen a physician in over 10 years.  The patient does not use tobacco or alcohol, and he works in the warehouse of an agricultural supply company.  BMI is 34 kg/m².  Physical examination shows a narrow oropharynx and a large neck circumference.  The patient is at increased risk of developing which of the following?

A 34-year-old man comes to the office due to shortness of breath.  He reports an episodic cough and chest tightness for the past 4 months.  The patient was recently on a 2-week vacation in Arizona and reports that he had no symptoms during the trip but that they restarted when he returned home.  He has no prior medical conditions and takes no medications.  The patient smoked marijuana in his early 20s for several years but does not use tobacco or alcohol.  He started working at a chemical manufacturing factory 7 months ago and has had no sick contacts.  Temperature is 36.7 C (98 F), blood pressure is 120/80 mm Hg, pulse is 76/min, and respirations are 18/min.  On physical examination, expiration is mildly prolonged and there are scattered wheezes.  Office spirometry shows an FEV1/FVC of 82%, and chest radiography reveals no abnormalities.  Which of the following features is most likely involved in the pathogenesis of this patient’s condition?

A 42-year-old man comes to his primary care physician due to daytime sleepiness.  He often falls asleep during meetings and while watching television and has even fallen asleep while driving.  The patient does not feel refreshed when waking and has occasional morning headaches.  He has not had abnormal dreams or visual hallucinations when falling asleep or on waking.  The patient has no significant past medical history and is a lifetime non-smoker.  He drinks 2 or 3 beers on Friday nights.  Blood pressure is 148/100 mm Hg and pulse is 78/min and regular; BMI is 32 kg/m².  Cardiopulmonary examination shows no abnormalities.  Arterial blood gas analysis is normal.  What is this patient’s most likely diagnosis?

A 34-year-old woman comes to the office due to progressive exertional dyspnea for the past 6 months.  She has no chest pain, lightheadedness, or syncope.  Medical history is unremarkable and the patient takes no medications.  She does not use tobacco, alcohol, or illicit drugs.  The patient’s mother died of pulmonary arterial hypertension at age 32.  Blood pressure is 125/74 mm Hg and pulse is 75/min.  BMI is 23 kg/m².  On physical examination, breath sounds are clear without wheezes or crackles.  There is a loud S2 at the left upper sternal border.  Chest x-ray reveals clear lungs.  ECG shows right axis deviation.  If this patient’s condition is inherited, which of the following is the most likely direct cause of her disease?

A 63-year-old man comes to the emergency department due to a 1-week history of progressively worsening shortness of breath and cough.  The shortness of breath is exacerbated when the patient lies flat in bed; he has to prop himself up with 3 pillows to sleep well at night.  He was treated for a myocardial infarction 2 weeks ago and had 2 stents placed in the left anterior descending artery.  The patient’s other medical conditions include long-standing hypertension and type 2 diabetes mellitus.  Blood pressure is 120/80 mm Hg, pulse is 92/min, and respirations are 22/min.  Pulse oximetry is 89% on room air.  Physical examination reveals bilateral crackles at the lung bases and an S3.  Which of the following is most likely present in this patient?

A 76-year-old man has had worsening shortness of breath, cough, and weight loss for the past several months.  He is a lifelong nonsmoker.  Chest imaging reveals irregular pleural thickening.  A surgical biopsy is planned, but the patient refuses, choosing to receive hospice care instead.  He dies several weeks later.  Autopsy examination is performed, and a photograph of the cut lung section is shown below.

Histopathological examination of the abnormal tissue is most likely to reveal which of the following findings?

A 63-year-old woman comes to the office due to slowly progressive dyspnea on exertion and cough productive of white-yellow sputum over the past several years.  She has a history of rheumatoid arthritis and seasonal allergies.  The patient has smoked a pack of cigarettes daily for 40 years.  Blood pressure is 135/80 mm Hg and pulse is 76/min.  Lung examination demonstrates mild, bilateral expiratory wheezes, and chest x-ray reveals hyperinflated lungs.  Pulmonary function test results are as follows:

Which of the following cells most likely played a major role in the pathogenesis of this patient’s lung condition?

A 76-year-old man is brought to the emergency department after being involved in a motor vehicle collision.  He is found to have a laceration of the spleen and is taken for emergent laparotomy.  During surgery, the patient goes into cardiac arrest and dies, despite aggressive resuscitation efforts.  Autopsy examination is performed and shows areas of thickening inside the chest wall as shown below.

Lung examination shows fibrosis of the lower lobes.  Pathologic examination of these fibrotic areas is most likely to reveal which of the following findings?

A 48-year-old man is evaluated for shortness of breath and dry cough for 1 week.  The patient has never had similar symptoms in the past and takes no medications.  He has a 5-pack-year smoking history and does not use alcohol or illicit drugs.  The patient is a pig farmer in Ohio and has not traveled recently.  Temperature is 37.8 C (100 F), blood pressure is 128/85 mm Hg, pulse is 95/min, and respirations are 16/min.  Lung auscultation reveals scattered wheezing and crackles.  Peripheral blood smear is shown below.

The nucleated cells seen on this patient’s peripheral smear most likely perform which of the following functions?

A 38-year-old man comes to the office with reports of dyspnea on exertion and decreased exercise tolerance.  His medical history is unremarkable, and he has no history of childhood asthma or cough.  He has never smoked and has no known occupational exposures.  The patient has gained almost 100 lb over the past 4 years since leaving the military due to a sedentary lifestyle.  He currently weighs 135 kg (297.6 lb) and has a BMI of 41 kg/m².  His respiratory rate is 22/min and pulse oximetry is 93% on room air at rest.  Physical examination is notable for central obesity.  Lungs are clear on auscultation bilaterally.  Which of the following changes (forced expiratory volume in 1 second [FEV₁], forced vital capacity [FVC], expiratory reserve volume [ERV], residual volume [RV], and total lung capacity [TLC]) are most likely to be seen on pulmonary function testing in this patient?

A research study is conducted to evaluate the effects of various serum proteins in healthy and diseased states.  Healthy volunteers and patients with various medical conditions are recruited.  In an experiment, purified elastin is exposed to stimulated neutrophils, which results in the degradation of the elastin molecules into smaller peptides.  This process can be inhibited by adding serum from healthy volunteers but not from a specific patient population.  Which of the following is the strongest recommendation for patients in this specific population?

A 33-year-old woman comes to the office due to worsening exertional dyspnea.  She previously jogged frequently, but now becomes short of breath while walking her dog in the park.  The patient has no other significant medical history and takes no medications.  She smokes a pack of cigarettes daily and does not use alcohol or illicit drugs.  Blood pressure is 124/76 mm Hg, pulse is 78/min, and respirations are 20/min.  BMI is 27 kg/m².  Cardiac examination is unremarkable.  Laboratory studies reveal markedly decreased serum alpha-1 antitrypsin levels.  Which of the following pulmonary function test patterns is most likely to be present in this patient?

A 14-year-old girl is brought to the office due to intermittent shortness of breath over the past 4 months.  She is unable to link the episodes to specific events or exposures.  The patient has no prior medical conditions and takes no medications.  She does not smoke and has no second-hand tobacco exposure.  Her family has a cat that remains indoors.  There is no significant family history.  Blood pressure is 110/65 mm Hg, pulse is 80/min, and respirations are 16/min.  On physical examination, heart sounds are normal and the lungs are clear to auscultation.  Lung function tests reveal a FEV1/FVC ratio of 83%.  Which of the following would be most helpful in excluding a diagnosis of asthma in this patient?

A 62-year-old man comes to the office due to shortness of breath.  His symptoms have progressed over the last few months and have begun to limit his daily activities.  He has no other medical problems and takes no medications.  The patient drinks 3 or 4 alcoholic beverages a week and has a 50-pack-year smoking history.  Physical examination reveals decreased breath sounds and scattered wheezes bilaterally.  Chest x-ray is shown below.

Which of the following parameters is most likely to be increased in this patient?

A 64-year-old woman comes to the emergency department with a 4-day history of productive cough and breathlessness.  Her medical conditions include polymyalgia rheumatica, for which she takes low-dose prednisone.  Physical examination shows dullness to percussion and decreased breath sounds over the right lower lobe.  The abdomen is soft, nondistended, and nontender.  Chest x-ray shows a right lower lobe parenchymal opacity and a moderate right pleural effusion.  Thoracentesis is performed, yielding serosanguinous fluid.  Pleural fluid and serum findings are as follows:

Which of the following is contributing most to the pathogenesis of this patient’s pleural effusion?

A 62-year-old man comes to the office for evaluation of progressive exertional dyspnea.  His medical history is significant for pneumonia and hypertension.  He has a 45-pack-year smoking history.  On physical examination, breath sounds are decreased bilaterally and wheezes are heard.  A CT scan of the chest is shown below.

Increased activity of which of the following cells is most likely responsible for the development of this patient’s lung condition?

A 53-year-old man is being evaluated for dyspnea.  The graph on the right shows how the patient’s work of breathing varies with respiratory rate, whereas the graph on left represents the work of breathing versus respiratory rate in a normal individual.  The minute ventilation is constant and equal in both graphs.

Which of the following is the most likely diagnosis in this patient?