A very concerned mother is at the clinic with her infant who has a large, soft lump on the side of his head. She tells the nurse that she noticed the lump about 8 hours after her baby's birth and that it seems to be getting bigger. One possible explanation for this is:

Correct Answer: C

Rationale: The correct answer is C: cephalhematoma. A cephalhematoma is a collection of blood between a baby's skull and the periosteum, typically occurring due to trauma during birth. In this case, the lump appeared 8 hours after birth, which aligns with the timeline for cephalhematoma development. It is soft because it consists of blood, and it can increase in size as the blood accumulates. Incorrect Choices: A: Hydrocephalus is an abnormal accumulation of cerebrospinal fluid within the brain, not a collection of blood. B: Craniosynostosis is the premature fusion of skull bones, leading to an abnormal head shape, not a collection of blood. D: Caput succedaneum is swelling of the soft tissues of a newborn's scalp due to pressure during delivery, not a collection of blood.

Correct Answer: D

Rationale: The correct answer is D because tracheal shift due to thyroid enlargement occurs when the thyroid gland enlarges and displaces the trachea to the opposite side. This is a common clinical finding in conditions like a goiter. Other choices are incorrect because: A is incorrect as tracheal shift is not related to systole; B is incorrect as tracheal shift is typically caused by a mass pushing the trachea; C is incorrect as pleural adhesions don't typically cause tracheal shift.

Correct Answer: B

Rationale: The correct answer is B: not palpable. In healthy adults, most lymph nodes are not palpable as they are typically small and not easily detectable through touch. This indicates normal lymphatic function and absence of significant inflammation or infection. Choices A, C, and D describe characteristics of abnormal lymph nodes, such as being shotty, large/firm/fixed, or rubbery/discrete/mobile, respectively, which are indicative of pathological conditions like infection, malignancy, or inflammation. Therefore, the absence of palpable lymph nodes in a healthy individual is the expected norm.

Correct Answer: D

Rationale: The correct answer is D because a bruit in a 3-year-old child, especially over the temporal area, is not a normal finding and could indicate a serious underlying issue such as an arteriovenous malformation or other vascular abnormality. Stopping the examination and notifying the physician is crucial for further evaluation and management. A: Continuing the examination is not appropriate as the bruit should prompt further investigation. B: Checking again in 1 hour is unnecessary delay in addressing a potentially serious issue. C: Notifying the parents alone without medical intervention may delay necessary evaluation and treatment.

Correct Answer: C

Rationale: The correct answer is C because the trigeminal (CN V) and the trochlear (CN IV) nerves are indeed stimulated when the outer surface of the eye is stimulated. The trigeminal nerve is responsible for the sensation of touch in the face and controls the muscles involved in chewing. The trochlear nerve controls the superior oblique muscle of the eye, which helps with downward and inward eye movements. Therefore, when the outer layer of the eye is touched or stimulated, these nerves are activated to convey the sensation to the brain. Choices A, B, and D are incorrect: A: The outer layer of the eye is not particularly sensitive to touch compared to other areas like the cornea or conjunctiva. B: The outer layer of the eye is not darkly pigmented; the pigmented layer is actually the uvea inside the eye. D: The visual receptive layer of the eye, known as the retina, is located deeper within the eye, not