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: A

Rationale: Rationale: 1. Cefuroxime and nitrofurantoin are safe for use in pregnancy and effective against UTIs. 2. Cefuroxime is a cephalosporin antibiotic, considered safe in pregnancy. 3. Nitrofurantoin is a first-line agent for UTIs in pregnancy due to its safety profile. 4. Ciprofloxacin and tetracycline are contraindicated in pregnancy due to potential harm to the fetus. 5. Amoxicillin is considered safe in pregnancy but not as effective as nitrofurantoin for UTIs.

Correct Answer: B

Rationale: The correct answer is B: Small amplitude, weak. In congestive heart failure, the heart's ability to pump effectively is compromised, leading to decreased cardiac output. This results in a weakened pulse with reduced amplitude. Palpating a small, weak pulse in this patient is expected due to poor cardiac function. Choices A and C are incorrect because a large, forceful pulse is not expected in congestive heart failure, and a normal pulse may not reflect the compromised cardiac function. Choice D, bigeminal, refers to an abnormal rhythm characterized by every other heartbeat being premature and is not typically associated with congestive heart failure.

Correct Answer: A

Rationale: The correct answer is A: The fovea. The fovea is the central focal point for incoming images because it contains a high concentration of cones, which are responsible for detailed central vision. Cones are essential for color vision and visual acuity. The macula, while important for central vision, refers to the area surrounding the fovea. The optic disk is where the optic nerve exits the eye, and it does not receive incoming images. The physiologic cup is a normal depression in the optic nerve head and is not involved in image reception. In conclusion, the fovea is the correct answer as it is the area with the highest visual acuity due to the dense concentration of cones.

Correct Answer: A

Rationale: The correct answer is A because dopamine, serotonin, and norepinephrine are neurotransmitters commonly associated with mood regulation. Medications that affect these neurotransmitters can lead to symptoms of depression as a side effect. B: Gabapentin is not primarily associated with mood regulation. C: Milnacipran is an SNRI used to treat depression, not cause it. D: Cortisol is a stress hormone, not a neurotransmitter directly linked to depression symptoms.

Correct Answer: C

Rationale: Step 1: Identify the characteristics of the lesion described - dome-shaped, in dermis, benign, closed sac attached to epidermis. Step 2: A cutaneous cyst fits all these characteristics - it is a benign closed sac in the dermis with attachment to the epidermis. Step 3: Keloid (A) is an overgrowth of scar tissue, not a closed sac lesion. Tophi (B) are deposits of uric acid crystals, not a sac. Chondrodermatitis (D) is inflammation of cartilage and skin, not a closed sac lesion. Summary: A cutaneous cyst is the correct choice as it matches all the characteristics given, while the other options do not fit the description provided.

Correct Answer: D

Rationale: The correct answer is D: A bone marrow examination. Acute lymphocytic leukemia is a type of blood cancer that affects the bone marrow's ability to produce normal blood cells. A bone marrow examination is necessary to confirm the diagnosis by analyzing the bone marrow cells for abnormality. A complete blood count (choice A) can show abnormalities in blood cell counts but cannot confirm leukemia. Magnetic resonance imaging (choice B) and nuclear bone scan (choice C) are imaging tests that can show bone abnormalities but are not specific for diagnosing leukemia.

Correct Answer: B

Rationale: The correct answer is B: Hirsutism. Hirsutism is the presence of excessive hair growth in a male pattern distribution in women, which is a common sign of hyperandrogenism. Elevated androgen levels can lead to hirsutism in women, especially in conditions like polycystic ovary syndrome. High pitch voice (A) and obesity (D) are not direct indicators of hyperandrogenism. While polycystic ovaries (C) can be associated with hyperandrogenism, the presence of hirsutism is a more specific and direct finding in this scenario.

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.