Correct Answer: D

Rationale: The correct answer is D because it provides an accurate explanation for the frequent ear infections in the 2-year-old. The eustachian tube in children is indeed shorter and wider compared to adults, making it easier for infections to develop. This anatomical difference predisposes young children to ear infections. Choice A is incorrect because it falsely implies that frequent ear infections in small children are unusual only if something else is wrong. Choice B is incorrect as checking the immune system is not typically the first step in addressing recurrent ear infections. Choice C is incorrect as cerumen (earwax) does not directly contribute to ear infections in the middle ear.

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

Correct Answer: B

Rationale: The correct answer is B: acute otitis media. In this case, the presentation of a bright red tympanic membrane and absence of the light reflex are indicative of inflammation and fluid accumulation in the middle ear, which are classic signs of acute otitis media. This condition commonly occurs in young children, especially after a recent upper respiratory infection. Incorrect choices: A: Fungal infection is less likely in this case as the symptoms are more consistent with acute bacterial infection seen in otitis media. C: Rupture of the drum would typically present with sudden relief of pain and discharge from the ear, which is not described in the scenario. D: Blood behind the drum (hemotympanum) is uncommon in children with acute otitis media and would usually be associated with trauma or barotrauma.

Correct Answer: A

Rationale: The correct answer is A: At birth, the head is one fifth the total length. This is because newborns have relatively larger heads compared to their body size. This is known as cephalocaudal growth, where development starts from the head and progresses down the body. The head being one-fifth of the total length is a normal proportion in newborns. Choice B is incorrect because at birth, the chest circumference is usually greater than the head circumference. Choice C is incorrect as the head size reaches about 80% of its final size by age 2, not 3 years old. Choice D is incorrect because the closure of the anterior fontanelle at 2 months does not necessarily mean the head will appear proportionate to the body; it continues to grow in proportion to the body size.

Correct Answer: B

Rationale: The correct answer is B: hyphema. Hyphema is the presence of blood in the anterior chamber of the eye, which can occur due to trauma like being hit with a baseball bat. This indicates bleeding inside the eye, specifically in the space between the cornea and iris. Hypopyon (A) is the accumulation of white blood cells in the anterior chamber. Corneal abrasion (C) is a scratch on the cornea, not related to blood in the anterior chamber. Iritis (D) is inflammation of the iris, which does not necessarily involve blood in the anterior chamber.