Which term identifies the bone forming part of the posterior portion of the nose and orbit?

Which term identifies the bone forming part of the posterior portion of the nose and orbit?

• A. Ethmoid bone
• B. Diaphysis
• C. Epiphysis
• D. Endosteum

Answer: (A)

The ethmoid bone is the one that fits here because it sits between the nasal cavity and the orbits and contributes to both structures. It forms key parts of the nasal septum (the perpendicular plate) and the walls of the nasal cavity (the ethmoidal labyrinth), and its orbital plates help make up the medial walls of the eye sockets. In contrast, the other terms refer to parts of a long bone or its lining, not a bone that forms facial or orbital structures. So the bone forming the posterior portion of the nose and orbit is the ethmoid bone.

The ethmoid bone is the one that fits here because it sits between the nasal cavity and the orbits and contributes to both structures. It forms key parts of the nasal septum (the perpendicular plate) and the walls of the nasal cavity (the ethmoidal labyrinth), and its orbital plates help make up the medial walls of the eye sockets. In contrast, the other terms refer to parts of a long bone or its lining, not a bone that forms facial or orbital structures. So the bone forming the posterior portion of the nose and orbit is the ethmoid bone.