Malleus

From Wikipedia, the free encyclopedia
Jump to: navigation, search
This article is about the ossicle. For other uses, see Malleus (disambiguation).
Malleus
Bones and muscles in the tympanic cavity in the middle ear
Gray916.png
Left malleus. A. From behind. B. From within.
Gray912.png
The right membrana tympani with the hammer and the chorda tympani, viewed from within, from behind, and from above. (Malleus visible at center.)
Details
Latin Malleus
1st branchial arch[1]
Identifiers
Gray's p.1044
MeSH A09.246.397.247.524
TA A15.3.02.043
FMA FMA:52753
Anatomical terms of bone

The malleus /ˈmæliəs/ 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.

Structure[edit]

See also: Ossicles

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.[2] :862

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.[3]

Development[edit]

Embryologically it is derived from the first pharyngeal arch along with the rest of the bones of mastication, such as the maxilla and mandible.

Function[edit]

Main article: Hearing

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.[2] :862

History[edit]

Additional images[edit]

Ossicles 
Head 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 malleus 
Auditory ossicles. Tympanic cavity. Deep dissection. 
Auditory ossicles. Incus and malleus. Deep dissection. 

See also[edit]

This article uses anatomical terminology; for an overview, see anatomical terminology.

References[edit]

  1. ^ hednk-023 — Embryo Images at University of North Carolina
  2. ^ a b Drake, Richard L.; Vogl, Wayne; Tibbitts, Adam W.M. Mitchell; illustrations by Richard; Richardson, Paul (2005). Gray's anatomy for students. Philadelphia: Elsevier/Churchill Livingstone. ISBN 978-0-8089-2306-0. 
  3. ^ Ramachandran, V. S.; Blakeslee, S. (1999). Phantoms in the Brain. Quill. p. 210. ISBN 9780688172176.