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Correct Answer: C

Explanation:

Diphyllobothrium latum is a tapeworm which can cause vitamin B12 deficiency because it competes for this vitamin in the small intestine. Infection with this tapeworm occurs after consumption of raw or undercooked freshwater fish. Vitamin B12 deficiency may occur in infected patients and presents with fatigue due to the macrocytic megaloblastic anemia with hyper segmented neutrophils. Treatment of the infection is with praziquantel.

Correct Answer: E

Explanation: This patient's low BMI and a year long history of poor eating habits are consistent with anorexia nervosa. Anorexic patients have an unreasonable fear of gaining weight and “feel fat" even when overweight and engage in prolonged physical activity in order to lose weight. This patient most likely started eating poorly after her breakup with her boyfriend. Metatarsal stress fractures are a complication of rigorous physical activity in patients with anorexia due to chronic malnourishment which results in low bone density. Other findings include amenorrhea, electrolyte disturbances, lanugo, anemia and coexisting depression. Psychotherapy and nutritional rehabilitation are first line treatments.

Correct Answer: E

Explanation:

Because the right main bronchus is wider and more vertical than the left, foreign objects are more likely to be aspirated into the right main bronchus. The superior segmental bronchus of the lower lobar bronchus is the only segmental bronchus that exits from the posterior wall of the lobar bronchi. Therefore, if a patient is supine at the time of aspiration, the object is most likely to enter the superior segmental bronchus of the lower lobe. None of the segmental bronchi of the left lung are likely to receive the object because the object is less likely to enter the left main bronchus. The apical segment of the right upper lobe is not likely to receive the foreign object because of the sharp angle that the upper lobar bronchus makes with the right main bronchus, and the sharp angle that the apical segmental bronchus makes with the lobar bronchus. The medial segmental bronchus of the right middle lobe arises from the anterior wall of the right middle lobar bronchus. Therefore, when the patient is supine, the effect of gravity will tend to prevent the object from entering this segmental bronchus.