A new mother is concerned that her child occasionally "turns blue." On further questioning, she mentions that this is at her hands and feet. She does not remember the child's lips turning blue. She is otherwise eating and growing well. What would you do now?

Correct Answer: A

Rationale: Step 1: "Turns blue" at hands and feet without lips involvement suggests acrocyanosis, a common benign condition in newborns. Step 2: Acrocyanosis is a result of immature circulation and is typically self-limiting. Step 3: The child is otherwise well-nourished and growing, indicating no acute distress. Step 4: Reassuring the mother about acrocyanosis being normal helps alleviate her concerns. Summary: B: Echocardiogram is unnecessary as the symptoms do not suggest structural heart disease. C: Hospitalization is excessive for a benign condition like acrocyanosis. D: Casting doubt on the mother's story is not appropriate without evidence otherwise.

Correct Answer: C

Rationale: The correct answer is C7 because the index finger is innervated by the C7 dermatome. Each spinal nerve innervates a specific area of skin called a dermatome. In this case, the C7 spinal nerve is responsible for providing sensory information to the skin over the index finger. Choices A (C5), B (C6), and D (C8) are incorrect as they do not correspond to the dermatome responsible for innervating the index finger. Therefore, the correct answer is C7 based on the specific dermatomal distribution of sensory fibers.

Correct Answer: C

Rationale: The correct answer is C, the Sartorius muscle. An ASIS avulsion fracture occurs due to a sudden and forceful contraction of the Sartorius muscle, which attaches to the ASIS. This muscle acts to flex, abduct, and laterally rotate the hip, and its abrupt contraction can lead to avulsion of the ASIS. The other choices, such as A (Long head of the biceps femoris), B (Vastus intermedius muscle), and D (Iliopsoas muscle), do not directly attach to the ASIS and are not involved in causing this specific type of fracture.

Correct Answer: A

Rationale: The correct answer is A: Scaphoid. A fall or blow on a hyperextended wrist can disrupt blood flow to the scaphoid bone, leading to osteonecrosis. The scaphoid is vulnerable due to its location and blood supply. Lunate (B), Triquetrum (C), and Pisiform (D) are less likely to be affected in this scenario due to their different anatomical locations and blood supplies.

Correct Answer: A

Rationale: The correct answer is A: Axial skeleton. Skeletal metastases commonly occur in the axial skeleton due to its rich blood supply and high bone turnover rate. This makes it a favorable site for cancer cells to metastasize. Metastases in the femur, humerus, and radius are less common compared to the axial skeleton. The long bones like femur, humerus, and radius are more prone to primary bone tumors rather than metastases. Therefore, the correct answer is A as it aligns with the typical pattern of skeletal metastases.