The ''incus'' or anvil is a

bone A bone is a rigid tissue Tissue may refer to: Biology * Tissue (biology), an ensemble of similar cells that together carry out a specific function * ''Triphosa haesitata'', a species of geometer moth found in North America * ''Triphosa dubit ...

bone

in the

middle ear The middle ear is the portion of the ear The ear is the organ of hearing and, in mammals, balance. In mammals, the ear is usually described as having three parts—the outer ear The outer ear, external ear, or auris externa is t ...

. The

anvil An anvil is a metalworking Metalworking is the process of shaping and reshaping metal A metal (from Ancient Greek, Greek μέταλλον ''métallon'', "mine, quarry, metal") is a material that, when freshly prepared, polished, or fr ...

anvil

-shaped small bone is one of three

ossicles The ossicles (also called auditory ossicles) are three bone A bone is a rigid tissue Tissue may refer to: Biology * Tissue (biology), an ensemble of similar cells that together carry out a specific function * ''Triphosa haesitata'', a spe ...

in the middle ear. The ''incus'' receives vibrations from the ''

malleus The malleus, or hammer, is a hammer-shaped small bone or ossicle The ossicles (also called auditory ossicles) are three bone A bone is a Stiffness, rigid tissue (anatomy), tissue that constitutes part of the vertebrate skeleton in animals. ...

malleus

'', to which it is connected laterally, and transmits these to the ''

stapes The ''stapes'' or stirrup is a bone in the middle ear of humans and other animals which is involved in the conduction of sound vibrations to the inner ear. This bone is connected to the oval window by its Annular ligament of stapes, annular ligam ...

'' medially. The ''incus'' is so-called because of its resemblance to an anvil ( la, Incus).

Structure

The incus is the second of the

, three bones in the

which act to transmit sound. It is shaped like an

, and has a long and short crus extending from the body, which articulates with the

. The short crus attaches to the

posterior ligament of the incus The Posterior ligament of the incus is a fibrous band that connects the tip of the short crus of the incus The ''incus'' or anvil is a bone in the middle ear. The anvil-shaped small bone is one of three ossicles in the middle ear. The ''incus'' ...

. The long crus articulates with the

stirrup A stirrup is a light frame or ring that holds the foot of a rider, attached to the saddle The saddle is a supportive structure for a rider of an animal, fastened to Mammal#Anatomy, an animal's back by a girth (tack), girth. The most com ...

at the lenticular process. The

superior ligament of the incus The Superior ligament of the incus is a fibrous band that crosses from the body of the incus The ''incus'' or anvil is a bone in the middle ear. The anvil-shaped small bone is one of three ossicles in the middle ear. The ''incus'' receives vibra ...

attaches at the body of the incus to the roof of the

tympanic cavity The tympanic cavity is a small cavity surrounding the bones of the middle ear The middle ear is the portion of the ear internal to the eardrum, and external to the oval window of the inner ear. The mammalian middle ear contains three ossicles, ...

Function

Vibrations in the

are received via the

tympanic membrane In the anatomy Anatomy (Greek ''anatomē'', 'dissection') is the branch of concerned with the study of the structure of s and their parts. Anatomy is a branch of natural science which deals with the structural organization of living thing ...

. The malleus, resting on the membrane, conveys vibrations to the incus. This in turn conveys vibrations to the

History

"Incus" means "anvil" in Latin. Several sources attribute the discovery of the incus to the anatomist and philosopher

Alessandro Achillini Alessandro Achillini (''Latin'' Alexander Achillinus; 20 or 29 October 1463 (or possibly 1461)2 August 1512) was an Italian Italian may refer to: * Anything of, from, or related to the country and nation of Italy ** Italians, an ethnic group or si ...

. The first brief written description of the ''incus'' was by

Berengario da Carpi Jacopo Berengario da Carpi (also known as Jacobus Berengarius Carpensis, Jacopo Barigazzi, Giacomo Berengario da Carpi or simply Carpus; c. 1460 – c. 1530) was an Italian physician. His book "''Isagoge breves''" published in 1522 made him the most ...

in his ''Commentaria super anatomia Mundini'' (1521).

Andreas Vesalius Andreas Vesalius (; 31 December 1514 – 15 October 1564) was a 16th-century Flemish people, Flemish anatomist, physician, and author of one of the most influential books on human anatomy, ''De humani corporis fabrica, De Humani Corporis Fabrica ...

, in his ''

De humani corporis fabrica ''De Humani Corporis Fabrica Libri Septem'' (Latin Latin (, or , ) is a classical language belonging to the Italic languages, Italic branch of the Indo-European languages. Latin was originally spoken in the area around Rome, known as Lat ...

'', was the first to compare the second element of the ossicles to an anvil, thereby giving it the name ''incus''. The final part of the long limb was once described as a "fourth ossicle" by

Pieter Paaw Pieter is a male given name, the Dutch Dutch commonly refers to: * Something of, from, or related to the Netherlands * Dutch people () * Dutch language () *Dutch language , spoken in Belgium (also referred as ''flemish'') Dutch may also refe ...

in 1615.

Additional images

File:Illu auditory ossicles-en.svg, Ossicles File:Occipital bone dissection.jpg, Tympanic cavity. Facial canal. Internal carotid artery. File:Slide1ghe.JPG, Auditory ossicles. Tympanic cavity. Deep dissection. File:Slide2ghe2.JPG, Aditory ossicles. Incus and malleus. Deep dissection.

References

External links