Malleus

The malleus or hammer is a hammer-shaped small bone or ossicle of the middle ear which connects with the incus and is attached to the inner surface of the eardrum. The word is Latin for hammer or mallet. It transmits the sound vibrations from the eardrum to the incus.OssiclesHead and neck of a human embryo eighteen weeks old, with Meckel's cartilage and hyoid bone exposed.External and middle ear, opened from the front. Right side.Chain of ossicles and their ligaments, seen from the front in a vertical, transverse section of the tympanum.CT image of malleusAuditory ossicles. Tympanic cavity. Deep dissection.Auditory ossicles. Incus and malleus. Deep dissection. The malleus or hammer is a hammer-shaped small bone or ossicle of the middle ear which connects with the incus and is attached to the inner surface of the eardrum. The word is Latin for hammer or mallet. It transmits the sound vibrations from the eardrum to the incus. The malleus is a bone situated in the middle ear. It is the first of the three ossicles, and attached to the tympanic membrane. The head of the malleus is the large protruding section, which attaches to the incus. The head connects to the neck of malleus, and the bone continues as the handle of malleus, which connects to the tympanic membrane. Between the neck and handle of the malleus, lateral and anterior processes emerge from the bone. The malleus is unique to mammals, and evolved from a lower jaw bone in basal amniotes called the articular, which still forms part of the jaw joint in reptiles and birds. Embryologically it is derived from the first pharyngeal arch along with the incus. The malleus is one of three ossicles in the middle ear which transmit sound from the tympanic membrane (ear drum) to the inner ear. The malleus receives vibrations from the tympanic membrane and transmits this to the incus. Several sources attribute the discovery of the malleus to the anatomist and philosopher Alessandro Achillini. The first brief written description of the malleus was by Berengario da Carpi in his Commentaria super anatomia Mundini (1521). Niccolo Massa's Liber introductorius anatomiae described the malleus in slightly more detail and likened both it and the incus to little hammers terming them malleoli.