Bones are constantly undergoing resorption (breaking bone down) for various reasons. Which of the following cells accomplishes this process?

Choice A reason: Flat bones are typically thin and broad, such as the sternum or skull bones. They do not match the described dimensions of Emily’s bone.

Choice B reason: Irregular bones have complex shapes that do not fit into other categories, such as vertebrae. The bone described is not irregular.

Choice C reason: Short bones are roughly cube-shaped and found in areas like the wrist and ankle. A bone that is 3 inches long does not fit this category.

Choice D reason: Long bones are characterized by being longer than they are wide, typically found in the limbs. A bone that is 3 inches long and 1 inch wide fits this classification.

Choice E reason: Sesamoid bones are small, round bones embedded in tendons, like the patella. The described bone does not fit this category

Choice A reason: Inversion refers to turning the sole of the foot inward, toward the midline. It is a side-to-side movement at the ankle and does not elevate the heel or involve tiptoe posture.

Choice B reason: Plantar flexion is the correct answer. It involves pointing the toes downward and lifting the heel off the ground, which is exactly the motion used when standing on tiptoes. This movement occurs at the ankle joint and is essential for actions like walking, jumping, and reaching upward.

Choice C reason: Eversion is the opposite of inversion and involves turning the sole of the foot outward. Like inversion, it is a lateral movement and unrelated to tiptoe posture.

Choice D reason: Dorsiflexion is the opposite of plantar flexion. It involves lifting the toes upward toward the shin, such as when walking on heels. It does not help in reaching upward.

Choice E reason: Supination refers to rotating the forearm so the palm faces upward or forward. It is unrelated to foot movement or standing on tiptoes.