American Society of Radiologic Technologist (ASRT) Practice Exam

Which of the following is a cranial bone that is also part of the orbit?

1. Ethmoid

2. Lacrimal

3. Zygoma

4. Palatine

The correct answer is: Ethmoid

The ethmoid bone is indeed a cranial bone that also forms part of the orbit. It is located between the nasal cavity and the orbits, playing an essential role in the structure of the skull and the partitioning of the nasal sinuses. The ethmoid contains the superior and middle nasal conchae, and its orbital plates contribute to the medial wall of the eye socket. While the other bones listed may intersect with the orbit, they do not belong to the cranial category. The lacrimal bone is a facial bone that forms part of the orbit's medial wall, but it is not primarily a cranial bone. The zygoma, or cheekbone, and the palatine bone also belong to the facial skeleton and do not form a part of the cranial structure. Understanding the distinctions between cranial and facial bones is crucial for interpreting anatomy, especially in the context of structures surrounding the orbit.