1. Which of the following bones is the only movable bone of the skull?
Answer: D
The mandible is the only movable bone of the skull.
The mandible, also known as the lower jaw, is the only bone in the skull that can move, allowing for functions such as chewing and speaking.
A) Maxilla
The maxilla, or upper jawbone, is fixed and does not have the ability to move. It plays a crucial role in forming the upper jaw and parts of the facial structure but lacks the mobility characteristic of the mandible.
B) Zygomatic
The zygomatic bone, commonly referred to as the cheekbone, is also a stationary bone. It contributes to the structure of the face and the orbit but does not possess any joints that allow for movement.
C) Lacrimal
The lacrimal bones are small and fragile bones located at the front part of the medial wall of the orbit. Like the maxilla and zygomatic, they are immovable and serve mainly to support the structure of the eye socket.
D) Mandible
The mandible is the only movable bone of the skull, connected to the skull by the temporomandibular joint (TMJ). This joint allows for the movement necessary for actions such as biting and chewing.
Conclusion
The mandible's unique ability to move sets it apart from the other bones in the skull, which are all fixed in place. This distinction is critical for understanding the functional anatomy of the skull, as the mandible plays a vital role in mastication and communication, whereas the other options do not provide such mobility.