Which ossicle is known as the hammer?

The ossicle referred to as the hammer is the malleus. This specific bone is one of the three small bones located in the middle ear, and it is named for its hammer-like shape. The malleus is attached to the eardrum and plays a crucial role in the conduction of sound vibrations from the external environment into the inner ear. When sound waves hit the eardrum, the malleus vibrates and transmits these vibrations to the incus and then to the stapes, ultimately leading to the stimulation of the inner ear.

Understanding the roles of each ossicle is essential for grasping how sound is transmitted through the auditory system. The incus, often referred to as the anvil, is the bone that connects the malleus to the stapes, which is known as the stirrup. Each has a specific shape and function, contributing to the overall mechanism of hearing, but the term "hammer" specifically designates the malleus.

The crus, however, refers to parts of the stapes and is not a standalone ossicle, which further establishes that the malleus is the correct answer for this question.