The nurse is reviewing the development of the newborn infant. Regarding the sinuses, which statement is true in relation to a newborn infant?

A. Aorta- right atrium-right ventricle-lungs-pulmonary vein→ left atrium→ left ventricle→ vena cava: This sequence is incorrect because blood does not flow from the aorta to the right atrium; rather, the aorta carries oxygenated blood from the left ventricle to the body. The vena cava brings deoxygenated blood into the right atrium.

B. Vena cava-right atrium-right ventricle-lungs-pulmonary artery-left atrium-left ventricle: This sequence is incorrect because the blood does not flow from the lungs directly into the left atrium via the pulmonary artery; instead, blood from the lungs returns to the left atrium via the pulmonary veins.

C. Right atrium → right ventricle → pulmonary vein → lungs → pulmonary artery → left atrium → left ventricle: This sequence is incorrect because the pulmonary veins carry oxygenated blood from the lungs to the left atrium, not to the right ventricle.

D. Right atrium → right ventricle → pulmonary artery → lungs → pulmonary vein → left atrium → left ventricle: This is the correct sequence of blood flow through the heart. Blood flows from the right atrium to the right ventricle, then to the pulmonary artery, which carries it to the lungs for oxygenation. After oxygenation, blood returns to the left atrium via the pulmonary veins and then flows into the left ventricle before being pumped out to the body through the aorta.

A. II: The optic nerve (cranial nerve II) is responsible for vision, including visual acuity and the afferent limb of the pupillary reflex. Damage to this nerve causes vision loss or visual field defects but does not affect eye movement or positioning.

B. VI: The abducens nerve (cranial nerve VI) innervates the lateral rectus muscle, which abducts the eye. Damage to this nerve results in an inability to move the eye laterally, leading to horizontal diplopia, but it does not cause a "down and out" eye position.

C. III: The oculomotor nerve (cranial nerve III) controls most of the extraocular muscles, including the superior, inferior, and medial rectus muscles, as well as the inferior oblique. It also controls the levator palpebrae superioris and the parasympathetic fibers responsible for pupillary constriction. Damage to cranial nerve III results in ptosis, a "down and out" eye position due to unopposed action of the lateral rectus (cranial nerve VI) and superior oblique (cranial nerve IV), and potentially a dilated pupil.

D. IV: The trochlear nerve (cranial nerve IV) innervates the superior oblique muscle, which depresses and internally rotates the eye. Damage to this nerve typically causes vertical diplopia and difficulty looking downward, especially when reading or descending stairs, but it does not cause a "down and out" eye position at rest.