Final answer:
In wound healing by secondary intention, open burn areas require more extensive granulation tissue and wound contraction to heal, distinguishing them from wounds that can heal by primary intention, like closed injuries beneath a cast.
Step-by-step explanation:
The question you're asking about involves the wound healing process and specifically the differences in healing by secondary intention. During secondary intention healing, wounds that are more significant and cannot be closed by primary means such as sutures, as in the cases of open burn areas or large gaping wounds, require more time and tissue to heal. This involves a more comprehensive response where a larger amount of granulation tissue is developed, and wound contraction plays a critical role in bringing the wound edges together, as opposed to primary intention where the edges are closely approximated and heal much quicker.
In your case, selecting open burn areas as an alteration requiring secondary intention healing is correct. Casted bone fractures, however, generally heal by primary intention beneath the cast, as the bones are held together in alignment to facilitate the healing process.