A 35-year-old previously healthy woman comes to the hospital due to several days of productive cough associated with chills and fever.  Her sputum is purulent with faint pink streaks of blood.  The patient also has sharp pain over the right shoulder and neck area brought on by deep inspiration.  Past medical history is unremarkable.  Her temperature is 38.3 C (101 F), blood pressure is 130/70 mm Hg, pulse is 98/min, and respirations are 22/min.  Examination reveals crackles and dullness over the right lower pulmonary lobe.  While listening with the stethoscope over the right midback, the examiner has the patient say the letter “E,” and the sound is perceived by the examiner as a loud letter “A.”  A chest x-ray is obtained and is shown in the image below.

The pain experienced by this patient is most likely carried by which of the following nerves?

A 66-year-old man hospitalized 3 days ago for left lower lobe pneumonia is evaluated for persistent fever.  He has been receiving the appropriate intravenous antibiotics as determined by antibiotic susceptibility testing of his sputum cultures.  The patient has a history of diabetes mellitus and hypertension.  His temperature is 38 C (100.4 F) and pulse is 87/min.  Examination shows dullness to percussion and decreased breath sounds over the left lower lung.  Imaging studies reveal a loculated, left-sided pleural effusion.  A tube is placed to drain the fluid via an incision at the 5th intercostal space in the midaxillary line.  Which of the following muscles is most likely to be dissected during the procedure?

A 22-year-old man is brought to the emergency department after being involved in a fight at a nearby bar.  The patient’s respiratory rate is 28/min, blood pressure is 88/60 mm Hg, and heart rate is 114/min.  Physical examination shows a penetrating right-sided stab wound along the upper surface of the clavicle between the lateral border of the sternum and the midclavicular line.  Which of the following structures was most likely injured?

A 63-year-old man is admitted to the hospital after suffering a cerebral infarction.  A swallow study performed during the acute recovery period shows oropharyngeal dysphagia.  Despite being maintained on the appropriate dietary restrictions, the patient experiences an episode of vomiting while lying on his back and subsequently develops pneumonia.  Which of the following lung regions is most likely to be affected?

A 32-year-old man comes to the hospital due to 1 week of progressive shortness of breath and cough.  He also reports sharp right-sided chest pain that is worsened by deep inspiration.  Examination reveals decreased tactile fremitus, dullness on percussion, and decreased breath sounds over the right lower lung.  Chest x-ray shows consolidation of the right lower lobe and a right-sided effusion.  A thoracentesis is performed, during which the needle is inserted along the upper border of the 10th rib at the right midaxillary line.  Which of the following structures is most at risk of being injured as a result of the intervention?

A 53-year-old man comes to the emergency department due to severe heartburn and difficulty swallowing for the last few weeks.  He has had mild to moderate heartburn for several years and has tried weight loss, elevating the head of his bed while sleeping, and several months of proton pump inhibitor therapy.  Other medical problems include hypertension and hypothyroidism.  Temperature is 36.7 C (98.1 F), blood pressure is 130/80 mm Hg, pulse is 78/min, and respirations are 16/min.  BMI is 25 kg/m².  Physical examination is unremarkable.  An upper gastrointestinal endoscopy is performed, and esophageal biopsy shows columnar epithelium with interspersed goblet cells.  A similar adaptive response can be seen in which of the following scenarios?

Fourth-year medical students are recruited for a research study assessing their ability to interpret biopsy samples obtained during routine clinical practice.  As part of the study, they are given samples of normal respiratory mucosa and asked to identify the cell types present after staining with hematoxylin and eosin.  The students observe that the respiratory epithelium changes in composition as the airways continue distally from the trachea to the alveolar ducts.  Which of the following features is last to disappear?

Physicians involved in regenerative medicine research conduct a series of animal experiments to determine pulmonary tissue regeneration capacity.  During one of the experiments, lung alveoli are exposed to NO₂ and massive necrosis of the epithelial lining ensues.  Histologic examination of the injured tissues a month later shows partial recovery of the alveolar epithelial lining.  This regenerated tissue is most likely derived from which of the following cell types?

A 23-year-old woman, gravida 2 para 1, with poorly controlled type 1 diabetes and hypothyroidism comes to the hospital with preterm, premature rupture of membrane at 30 weeks’ gestation.  Her medications include prenatal vitamins and insulin.  Vital signs are normal and examination shows clear vaginal discharge.  The patient’s cervix is closed and she has no uterine contractions.  Laboratory results are as follows:

Which of the following medications has the greatest positive impact on fetal survival?

The concentrations of 2 substances in the amniotic fluid of pregnant women are graphed below.

The two curves most likely correspond to which of the following?