What is the Malleus
The malleus, also known as the hammer, is the largest of the three middle ear ossicles and its name comes from the Latin word for a mallet.
Where is the Malleus Located
It is situated as the most lateral among the middle ear ossicles, being the initial ear bone encountered when entering the middle ear from the external ear, and directly attached to the tympanic membrane or eardrum.
Quick Facts
| Type | Irregular bone |
| Size (in a typical adult) | Height: About 8 mmWidth: About 3 mm |
| How many are there in the human body | 2 |
| Articulates with | Incus |
Functions
The primary function of the malleus is to transmit sound vibrations from the tympanic membrane to the incus, and then to the inner ear through the stapes and oval window, facilitating the perception and interpretation of sound.
Anatomy
Resembling a hammer in shape, the malleus consists of a head, neck, and multiple essential processes and landmarks.
The head is the oval, saddle-shaped posterior surface of the bone that connects with the incus, forming the incudomalleolar joint, a synovial joint. The neck, located just below the head, rests on top of the flaccid portion of the tympanic membrane, with a bony prominence below it where the malleus’s processes attach.
The manubrium (handle) extends downwards, connecting with the tympanic membrane, with a small projection on its medial wall serving as the attachment point for the tensor tympani muscle. The lateral process is a small cone-shaped projection at the base of the manubrium, attached to the upper part of the eardrum by the anterior and posterior malleolar folds.
The anterior process (Rau’s/Folian process) is a longer and more pronounced cone-shaped projection located between the malleus’s neck and the lateral process, attaching to the middle ear at the anterior wall.
Ligament Attachments
The malleus is suspended in place by the following three suspensory ligaments:
- Anterior malleal ligament (Casserio’s ligament): This ligament attaches the malleus’s neck to the anterior wall of the tympanic cavity.
- Superior malleal ligament: This ligament connects the head to the roof of the tympanic cavity.
- Lateral malleal ligament: This ligament attaches the malleal head (or neck) to the back of the tympanic notch.
References
- Malleus: RadioPaedia.org
- Malleus: IMAIOS.com
- Auditory ossicles: KenHub.com
- Malleus, Incus, & Stapes: Study.com
- Malleus: HealthLine.com
