A grandmother brings her 13-year-old grandson to you for evaluation. She noticed last week when he took off his shirt that his breastbone seemed collapsed. He seems embarrassed and tells you that it has been that way for quite a while. He states he has no symptoms from it and he just tries not to take off his shirt in front of anyone. He denies any shortness of breath, chest pain, or lightheadedness on exertion. His past medical history is unremarkable. He is in sixth grade and just moved in with his grandmother after his father was deployed to the Middle East. His mother died several years ago in a car accident. He states that he does not smoke and has never touched alcohol. On examination you see a teenage boy appearing his stated age. On visual examination of his chest, you see that the lower portion of the sternum is depressed. Auscultation of the lungs and heart are unremarkable. What disorder of the thorax best describes your findings?

Correct Answer: B

Rationale: The correct answer is B: Funnel chest (pectus excavatum). Pectus excavatum is characterized by a depressed or sunken appearance of the sternum, which matches the description provided in the case. In this condition, the chest wall is abnormally shaped inward. This can be a congenital condition or develop during growth spurts in adolescence. The lack of symptoms such as shortness of breath, chest pain, or lightheadedness on exertion is consistent with pectus excavatum, as these symptoms are not typically associated with this condition. The other choices (A: Barrel chest, C: Pigeon chest, D: Thoracic kyphoscoliosis) do not match the specific findings described in the case and are not associated with the characteristic sternal depression seen in pectus excavatum.

Correct Answer: B

Rationale: The correct answer is B: Chest pain and pleuritic breathing. This indicates possible complications like pleurisy or pleural effusion, requiring further evaluation. A: Persistent cough with sputum production is common in pneumonia. C: Shortness of breath is a typical symptom of pneumonia. D: Fever and chills are also common in pneumonia. However, chest pain and pleuritic breathing are more indicative of potential complications that may require immediate attention.

Correct Answer: D

Rationale: The correct answer is D: It can protect against anogenital lesions. The HPV vaccine can protect against several types of HPV that are known to cause anogenital warts and lesions. This is based on scientific evidence from clinical trials. A: Ideally it should be administered within 3 years of first intercourse - This statement is not accurate. The HPV vaccine is recommended for both males and females between the ages of 9 and 26, regardless of sexual activity. B: It covers against almost every HPV type - This statement is incorrect. While the HPV vaccine covers the most common high-risk HPV types that cause cervical cancer, it does not cover against every HPV type. C: It can be used as adjuvant therapy in cervical cancer - This statement is incorrect. The HPV vaccine is primarily used as a preventive measure to reduce the risk of HPV infection and related health issues, not as a treatment for existing cervical cancer.

Correct Answer: C

Rationale: The correct answer is C: Lower dose of antibiotics. The rationale is that the patient has early renal insufficiency, which means the kidney may have difficulty clearing medications from the body. Therefore, a lower dose of antibiotics is needed to prevent potential drug toxicity. A shorter course of antibiotics (choice A) may not be effective in treating pneumonia adequately. A longer course of antibiotics (choice B) may increase the risk of drug accumulation in the body. A higher dose of antibiotics (choice D) can lead to increased toxicity in a patient with renal insufficiency. Thus, the most appropriate option is to reduce the dose to ensure safe and effective treatment.

Correct Answer: C

Rationale: The pectinate or dentate line is the border between the anal canal and the rectum. This is true because it represents the transition between the endoderm-derived upper anal canal and the ectoderm-derived lower anal canal. It is an important anatomical landmark in colorectal surgery and in distinguishing different pathologies in the anal region. Choice A is incorrect because the pectinate or dentate line is not typically palpable. Choice B is incorrect as it does not demarcate areas supplied by different nervous systems. Choice D is incorrect as the pectinate or dentate line is visible on proctoscopic examination due to its distinct appearance.

Correct Answer: B

Rationale: The correct answer is B: Clonus. Clonus is a series of rhythmic, involuntary muscle contractions and relaxations that occur due to an abnormal response in the stretch reflex. In patients with neurological conditions like cerebral palsy, clonus is often observed due to increased muscle tone. Tremor (A) is a rhythmic shaking movement, not specifically associated with muscle contractions. Spasm (C) is a sudden, involuntary muscle contraction that is not typically rhythmic. Fasciculation (D) is a brief, spontaneous contraction of a small number of muscle fibers, not the rhythmic pattern seen in clonus.

Correct Answer: A

Rationale: The correct answer is A because guidelines for primary stroke prevention recommend using aspirin in individuals whose risk of stroke is high enough for the benefits to outweigh the risks. This is based on assessing individual risk factors such as age, hypertension, diabetes, smoking, and history of cardiovascular diseases to determine if the potential benefits of aspirin therapy in reducing the risk of stroke outweigh the potential risks such as gastrointestinal bleeding. Choices B, C, and D are incorrect because aspirin should not be used regardless of risk level, based on gender, or in specific populations without considering individual risk factors to ensure the benefits outweigh the risks.

Correct Answer: B

Rationale: The correct answer is B: Vomiting and pain. Small bowel obstruction typically leads to vomiting due to the blockage preventing food from passing through. Pain occurs as the intestine tries to push against the obstruction. Nausea and diarrhea (choice A) are more common in large bowel obstructions. Hematemesis and bloody stool (choice C) suggest bleeding in the upper gastrointestinal tract. Indigestion and anorexia (choice D) are not specific to small bowel obstruction. Therefore, the combination of vomiting and pain is indicative of small bowel obstruction.

Correct Answer: B

Rationale: The correct answer is B because decreased tactile fremitus suggests fluid or air in the pleural space, which can occur in conditions like pleural effusion or pneumothorax. This decrease in tactile fremitus is due to the transmission of vibrations from the vocal cords being impeded by the presence of fluid or air between the lung and chest wall. Choices A, C, and D are incorrect because decreased tactile fremitus is not typically associated with increased lung density, normal lung function, or lung tumors.