manubrium

Manubrium is a term used in anatomy to describe two distinct structures, both derived from the Latin word for “handle.” The two structures share the name because each resembles a handle in its respective context: the upper part of the sternum and the handle-like part of the malleus in the middle ear.

The manubrium sterni, or the manubrium of the sternum, is the broad, superior portion of the sternum. It forms the upper segment of the breastbone and serves as an important anatomical landmark. The manubrium articulates laterally with the clavicles at the sternoclavicular joints and with the first costal cartilages. Its inferior border meets the body of the sternum at the sternal angle (the manubriosternal junction). The superior border bears the jugular (suprasternal) notch. Muscular attachments include the sternohyoid and sternothyroid muscles. Clinically, the manubrium serves as a reference point in chest procedures and radiology and can be involved in trauma and mediastinal assessment.

The manubrium of the malleus, or the malleus handle, is part of the auditory ossicles in the middle ear. The malleus has a head, neck, and a long handle (the manubrium). The handle is embedded in the tympanic membrane along much of its length and extends medially toward the incus. By transmitting vibrations from the tympanic membrane to the incus, the manubrium plays a key role in the middle-ear mechanism of hearing.