Ossicles - Wikipedia Ossicles This article may be confusing or unclear to readers. Please help us clarify the article. There might be a discussion about this on the talk page. ( November 2017 ) This article is about the bones in the human ear. For elements embedded in the body wall of echinoderms, see Ossicle ( echinoderm ). Ossicles Auditory ossicles : Malleus, incus and stapes Details Part of Middle ear Identifiers Latin Ossicula auditus, ossicula auditoria MeSH D004429 TA A02. 1.17. 001 FMA 52750 Anatomical terms of bone ( edit on Wikidata ) This article is one of a series documenting the anatomy of the Human ear Outer ear Pinna Tragus Middle ear Tympanic membrane Ossicles Malleus Incus Stapes Inner ear Vestibules Utricle Saccule Cochlea Semicircular canals The ossicles ( also called auditory ossicles ) are three bones in either middle ear that are among the smallest bones in the human body. They serve to transmit sounds from the air to the fluid - filled labyrinth ( cochlea ). The absence of the auditory ossicles would constitute a moderate - to - severe hearing loss. The term `` ossicle '' literally means `` tiny bone ''. Though the term may refer to any small bone throughout the body, it typically refers to the malleus, incus, and stapes ( hammer, anvil, and stirrup ) of the middle ear. Contents 1 Structure 1.1 Development 1.2 Evolution 2 Function 3 Clinical relevance 4 History 5 See also 6 References 7 External links Structure See also : Malleus, Incus, and Stapes Anatomy of the three ossicles. The ossicles are, in order from the eardrum to the inner ear ( from superficial to deep ) : the malleus, incus, and stapes, terms that in Latin are translated as `` the hammer, anvil, and stirrup ''. The malleus ( Latin : `` hammer '' ) articulates with the incus through the incudomalleolar joint and is attached to the tympanic membrane ( eardrum ), from which vibrational sound pressure motion is passed. The incus ( Latin : `` anvil '' ) is connected to both the other bones. The stapes ( Latin : `` stirrup '' ) articulates with the incus through the incudostapedial joint and is attached to the membrane of the fenestra ovalis, the elliptical or oval window or opening between the middle ear and the vestibule of the inner ear. It is the smallest bone in the body. Development Studies have shown that ear bones in mammal embryos are attached to the dentary, which is part of the jaw. These are ossified portions of cartilage -- called Meckel 's cartilage -- that are attached to the jaw. As the embryo develops, the cartilage hardens to form bone. Later in development, the bone structure breaks loose from the jaw and migrates to the inner ear area. The structure is known as the middle ear, and is made up of the stapes, incus, malleus, and tympanic membrane. These correspond to the columella, quadrate, articular, and angular structures in the amphibian, bird or reptile jaw. For this reason, researchers believe that mammals and reptiles share a common ancestry. Evolution Main article : Evolution of mammalian auditory ossicles Function As sound waves vibrate the tympanic membrane ( eardrum ), it in turn moves the nearest ossicle, the malleus, to which it is attached. The malleus then transmits the vibrations, via the incus, to the stapes, and so ultimately to the membrane of the fenestra ovalis ( oval window ), the opening to the vestibule of the inner ear. Sound traveling through the air is mostly reflected when it comes into contact with a liquid medium ; only about 1 / 30 of the sound energy moving through the air would be transferred into the liquid. This is observed from the abrupt cessation of sound that occurs when the head is submerged underwater. This is because the relative incompressibility of a liquid presents resistance to the force of the sound waves traveling through the air. The ossicles give the eardrum a mechanical advantage via lever action and a reduction in the area of force distribution ; the resulting vibrations would be much weaker if the sound waves were transmitted directly from the outer ear to the oval window. This reduction in the area of force application allows a large enough increase in pressure to transfer most of the sound energy into the liquid. The increased pressure will compress the fluid found in the cochlea and transmit the stimulus. Thus, the presence of the ossicles to concentrate the force of the vibrations improves the sensitivity to sound and is a form of impedance matching. However, the extent of the movements of the ossicles is controlled ( and constricted ) by two muscles attached to them ( the tensor tympani and the stapedius ). It is believed that these muscles can contract to dampen the vibration of the ossicles, in order to protect the inner ear from excessively loud noise ( theory 1 ) and that they give better frequency resolution at higher frequencies by reducing the transmission of low frequencies ( theory 2 ) ( see acoustic reflex ). These muscles are more highly developed in bats and serve to block outgoing cries of the bats during echolocation ( SONAR ). Clinical relevance Occasionally the joints between the ossicles become rigid. One condition, otosclerosis, results in the fusing of the stapes to the oval window. This reduces hearing and may be treated surgically. History There is some doubt as to the discoverers of the auditory ossicles and several anatomists from the early 16th century have the discovery attributed to them with the two earliest being Alessandro Achillini and Jacopo Berengario da Carpi. Several sources, including Eustachi and Casseri, attribute the discovery of the malleus and incus to the anatomist and philosopher Achillini. The first written description of the malleus and incus was by Berengario da Carpi in his Commentaria super anatomia Mundini ( 1521 ), although he only briefly described two bones and noted their theoretical association with the transmission of sound. Niccolo Massa 's Liber introductorius anatomiae described the same bones in slightly more detail and likened them both to little hammers. A much more detailed description of the first two ossicles followed in Andreas Vesalius ' De humani corporis fabrica in which he devoted a chapter to them. Vesalius was the first to compare the second element of the ossicles to an anvil although he offered the molar as an alternative comparison for its shape. The first published description of the stapes came in Pedro Jimeno 's Dialogus de re medica ( 1549 ) although it had been previously described in public lectures by Giovanni Filippo Ingrassia at the University of Naples as early as 1546. The term ossicle derives from ossiculum, a diminutive of `` bone '' ( Latin : os ; genitive ossis ). The malleus gets its name from Latin malleus, meaning `` hammer '', the incus gets its name from Latin incus meaning `` anvil '' from incudere meaning `` to forge with a hammer '', and the stapes gets its name from Modern Latin `` stirrup, '' probably an alteration of Late Latin stapia related to stare `` to stand '' and pedem, an accusative of pes `` foot '', so called because the bone is shaped like a stirrup -- this was an invented Modern Latin word for `` stirrup, '' for which there was no classical Latin word, as the ancients did not use stirrups. See also This article uses anatomical terminology ; for an overview, see Anatomical terminology. Hearing Ear Incudomalleolar joint Incudostapedial joint Middle ear Otolith References Jump up ^ `` Your Bones ''. kidshealth.org. Jump up ^ Meng, Jin. `` The Journey From Jaw to Ear. '' Biologist. vol. 50. ( 2003 ) p. 154 - 158. Jump up ^ Hill, R.W., Wyse, G.A. & Anderson, M. ( 2008 ). Animal Physiology, 2nd ed... Jump up ^ O'Malley, C.D. ; Clarke, E ( 1961 ). `` The discovery of the auditory ossicles ''. Bulletin of the history of medicine. 35 : 419 -- 41. PMID 14480894. Jump up ^ Alidosi, GNP. I dottori Bolognesi di teologia, filosofia, medicina e d'arti liberali dall'anno 1000 per tutto marzo del 1623, Tebaldini, N., Bologna, 1623. http://gallica.bnf.fr/ark:/12148/bpt6k51029z/f35.image# Jump up ^ Lind, L.R. Studies in pre-Vesalian anatomy. Biography, translations, documents, American Philosophical Society, Philadelphia, 1975. p. 40 Jump up ^ Jacopo Berengario da Carpi, Commentaria super anatomia Mundini, Bologna, 1521. https://archive.org/details/ita-bnc-mag-00001056-001 ^ Jump up to : O'Malley, C.D. Andreas Vesalius of Brussels, 1514 -- 1564. Berkeley : University of California Press, 1964. p. 120 Jump up ^ Niccolo Massa, Liber introductorius anatomiae, Venice, 1536. p. 166. http://reader.digitale-sammlungen.de/en/fs1/object/display/bsb10151904_00001.html Jump up ^ Andreas Vesalius, De humani corporis fabrica. Johannes Oporinus, Basle, 1543. Jump up ^ O'Malley, C.D. Andreas Vesalius of Brussels, 1514 -- 1564. Berkeley : University of California Press, 1964. p. 121 Jump up ^ Pedro Jimeno, Dialogus de re medica, Johannes Mey, Valencia, 1549. https://archive.org/details/dialogusderemed00jimegoog Jump up ^ A Mudry, Disputes surrounding the discovery of the stapes in the mid 16th century., Otology and Neurotology, 2013 Apr ; 34 ( 3 ) : 588 - 92. Jump up ^ `` Online Etymology Dictionary ''. etymonline.com. Jump up ^ `` Online Etymology Dictionary ''. etymonline.com. Jump up ^ `` Online Etymology Dictionary ''. etymonline.com. Jump up ^ `` Online Etymology Dictionary ''. etymonline.com. External links Wikimedia Commons has media related to Ossicles. The middle ear and the ossicles Anatomy of hearing and balance Outer ear Auricle helix antihelix tragus antitragus intertragic notch earlobe Ear canal Auricular muscles Eardrum umbo pars flaccida Middle ear Tympanic cavity Medial structures oval window round window secondary tympanic membrane prominence of facial canal promontory of tympanic cavity Posterior structures mastoid cells aditus to mastoid antrum pyramidal eminence Ossicles Malleus superior ligament lateral ligament anterior ligament Incus superior ligament posterior ligament Stapes annular ligament Muscles stapedius tensor tympani Auditory tube / Eustachian tube Torus tubarius Inner ear / ( membranous labyrinth, bony labyrinth ) Auditory system / Cochlear labyrinth General cochlea Vestibular duct Helicotrema Tympanic duct Modiolus Cochlear cupula Perilymphatic space Perilymph Cochlear aqueduct Cochlear duct / scala media Reissner 's / vestibular membrane Basilar membrane Reticular membrane Endolymph Stria vascularis Spiral ligament Organ of Corti stereocilia tip links Tectorial membrane Sulcus spiralis externus internus Spiral limbus Cells Claudius cell Boettcher cell Vestibular system / Vestibular labyrinth Vestibule Utricle macula Saccule macula Kinocilium Otolith Vestibular aqueduct endolymphatic duct endolymphatic sac Ductus reuniens Semicircular canals Superior semicircular canal Posterior semicircular canal Horizontal semicircular canal Ampullary cupula Ampullae crista ampullaris Bones in the human skeleton Axial skeleton Skull Neurocranium occipital parietal frontal temporal sphenoid ethmoid Face nasal maxilla lacrimal zygomatic palatine inferior nasal conchae vomer mandible hyoid Ear ossicles malleus incus stapes Thorax sternum rib cage rib Vertebral column vertebrae cervical thoracic lumbar sacrum coccyx Appendicular Shoulder clavicle scapula Arm humerus ulna radius Hand carpals ( scaphoid, lunate bone, triquetral, pisiform, trapezium, trapezoid, capitate, hamate ) metacarpals phalanges ( prox, int, dist ) Pelvis ilium ischium pubis Leg femur patella fibula tibia Foot tarsals heelbone anklebone navicular cuneiform cuboid metatarsals phalanges proximal intermediate distal accessory accessory navicular GND : 4771419 - 0 Retrieved from `` https://en.wikipedia.org/w/index.php?title=Ossicles&oldid=837211190 '' Categories : Auditory system Bones of the head and neck Hidden categories : Pages with unresolved properties Wikipedia articles needing clarification from November 2017 All Wikipedia articles needing clarification Articles containing Latin - language text Wikipedia articles with GND identifiers Talk Contents About Wikipedia Alemannisch Bân - lâm - gú Català Čeština Cymraeg Deutsch Eesti Español فارسی Français Galego 한국어 Italiano עברית Lietuvių Bahasa Melayu Nederlands 日本 語 Norsk nynorsk Polski Română Русский Simple English Slovenčina Slovenščina Српски / srpski Suomi Svenska ไทย Українська Walon 中文 24 more Edit links This page was last edited on 19 April 2018, at 12 : 12. 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Question: where is the ossicles located in the ear
Answer: either middle ear