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Eardrum
In the anatomy of humans and various other tetrapods, the eardrum, also called the tympanic membrane or myringa, is a thin, cone-shaped membrane that separates the external ear from the middle ear. Its function is to transmit changes in pressure of sound from the air to the ossicles inside the middle ear, and thence to the oval window in the fluid-filled cochlea. The ear thereby converts and amplifies vibration in the air to vibration in cochlear fluid. The malleus bone bridges the gap between the eardrum and the other ossicles. Rupture or perforation of the eardrum can lead to conductive hearing loss. Collapse or retraction of the eardrum can cause conductive hearing loss or cholesteatoma. Structure Orientation and relations The tympanic membrane is oriented obliquely in the anteroposterior, mediolateral, and superoinferior planes. Consequently, its superoposterior end lies lateral to its anteroinferior end. Anatomically, it relates superiorly to the middle crani ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tympanic Membrane Retraction
Tympanic membrane retraction describes a condition in which a part of the eardrum lies deeper within the ear than its normal position. The eardrum comprises two parts: the pars tensa, which is the main part of the eardrum, and the pars flaccida, which is a smaller part of the eardrum located above the pars tensa. Either or both of these parts may become retracted. The retracted segment of eardrum is often known as a retraction pocket. The terms ''atelectasis'' or sometimes ''adhesive otitis media'' can be used to describe retraction of a large area of the pars tensa. Tympanic membrane retraction is fairly common and has been observed in one quarter of a population of British school children. Retraction of both eardrums is less common than having a retraction in just one ear. It is more common in children with cleft palate. Tympanic membrane retraction also occurs in adults. Attempts have been made to categorise the extent of tympanic membrane retraction though the validit ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Perforation Of The Eardrum
A perforated eardrum (tympanic membrane perforation) is a prick in the eardrum. It can be caused by infection (otitis media), trauma, overpressure (loud noise), inappropriate ear clearing, and changes in middle ear pressure. An otoscope can be used to view the eardrum to diagnose a perforation. Perforations may heal naturally or require surgery. Presentation A perforated eardrum leads to conductive hearing loss, which is usually temporary. Other symptoms may include tinnitus, ear pain, vertigo, or a discharge of mucus. Nausea and/or vomiting secondary to vertigo may occur. Causes A perforated eardrum can have one of many causes, such as: * Infection (otitis media). This infection may then spread through the middle ear and may reoccur. * Trauma. This may be caused by trying to clean ear wax with sharp instruments. It may also occur due to surgical complications. * Overpressure (loud noise or shockwave from an explosion). * Inappropriate ear clearing. * Flying with a sev ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Middle Ear
The middle ear is the portion of the ear medial to the eardrum, and distal to the oval window of the cochlea (of the inner ear). The mammalian middle ear contains three ossicles (malleus, incus, and stapes), which transfer the vibrations of the eardrum into waves in the fluid and membranes of the inner ear. The hollow space of the middle ear is also known as the tympanic cavity and is surrounded by the tympanic part of the temporal bone. The auditory tube (also known as the Eustachian tube or the pharyngotympanic tube) joins the tympanic cavity with the nasal cavity ( nasopharynx), allowing pressure to equalize between the middle ear and throat. The primary function of the middle ear is to efficiently transfer acoustic energy from compression waves in air to fluid–membrane waves within the cochlea. Structure Ossicles The middle ear contains three tiny bones known as the ossicles: '' malleus'', ''incus'', and '' stapes''. The ossicles were given their Latin names f ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Conductive Hearing Loss
Conductive hearing loss (CHL) is a type of hearing impairment that occurs when sound waves are unable to efficiently travel through the outer ear, tympanic membrane (eardrum), or middle ear structures such as the ossicles. This blockage or dysfunction prevents sound from being effectively conducted to the inner ear, resulting in reduced hearing ability. Common causes include ear infections, fluid in the middle ear, earwax buildup, damage to the eardrum, or abnormalities in the ossicles. CHL can occur alone or alongside sensorineural hearing loss, in which case it is classified as mixed hearing loss. Depending on the underlying cause, conductive hearing loss is often treatable and sometimes reversible through medical interventions, such as medication, surgery, or assistive devices like hearing aids. However, chronic or permanent cases may require long-term management to improve hearing and communication abilities. Causes Common causes of conductive hearing loss include: Exter ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Malleus
The ''malleus'', or hammer, is a hammer-shaped small bone or ossicle of the middle ear. It 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'' (anvil). Structure The malleus is a bone situated in the middle ear. It is the first of the three ossicles, and attached to the eardrum (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. The bone continues as the handle (or manubrium) 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 bone is oriented so that the head is superior and the handle is inferior. Development Embryologically, the malleus is derived from the first pharyngeal arch along with the ''incus''. In humans it grows from Meckel's ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ossicle
The ossicles (also called auditory ossicles) are three irregular bones in the middle ear of humans and other mammals, and are among the smallest bones in the human body. Although the term "ossicle" literally means "tiny bone" (from Latin ''ossiculum'') and may refer to any small bone throughout the body, it typically refers specifically to the malleus, incus and stapes ("hammer, anvil, and stirrup") of the middle ear. The auditory ossicles serve as a kinematic chain to transmit and amplify (intensity (physics), intensify) sound vibrations collected from the air by the ear drum to the fluid-filled labyrinth (inner ear), labyrinth (cochlea). The absence or pathology of the auditory ossicles would constitute a moderate-to-severe conductive hearing loss. Structure 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 () articulat ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ossicles
The ossicles (also called auditory ossicles) are three irregular bones in the middle ear of humans and other mammals, and are among the smallest bones in the human body. Although the term "ossicle" literally means "tiny bone" (from Latin ''ossiculum'') and may refer to any small bone throughout the body, it typically refers specifically to the malleus, incus and stapes ("hammer, anvil, and stirrup") of the middle ear. The auditory ossicles serve as a kinematic chain to transmit and amplify ( intensify) sound vibrations collected from the air by the ear drum to the fluid-filled labyrinth ( cochlea). The absence or pathology of the auditory ossicles would constitute a moderate-to-severe conductive hearing loss. Structure 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 () articulates with the incus through the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Eustachian Tube
The Eustachian tube (), also called the auditory tube or pharyngotympanic tube, is a tube that links the nasopharynx to the middle ear, of which it is also a part. In adult humans, the Eustachian tube is approximately long and in diameter. It is named after the sixteenth-century Italian anatomist Bartolomeo Eustachi. In humans and other tetrapods, both the middle ear and the ear canal are normally filled with air. Unlike the air of the ear canal, however, the air of the middle ear is not in direct contact with the atmosphere outside the body; thus, a pressure difference can develop between the atmospheric pressure of the ear canal and the middle ear. Normally, the Eustachian tube is collapsed, but it gapes open with swallowing and with positive pressure, allowing the middle ear's pressure to adjust to the atmospheric pressure. When taking off in an aircraft, the ambient air pressure goes from higher (on the ground) to lower (in the sky). The air in the middle ear expands as ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tetrapod
A tetrapod (; from Ancient Greek :wiktionary:τετρα-#Ancient Greek, τετρα- ''(tetra-)'' 'four' and :wiktionary:πούς#Ancient Greek, πούς ''(poús)'' 'foot') is any four-Limb (anatomy), limbed vertebrate animal of the clade Tetrapoda (). Tetrapods include all Neontology#Extant taxa versus extinct taxa, extant and Extinction, extinct amphibians and amniotes, with the latter in turn Evolution, evolving into two major clades, the Sauropsida, sauropsids (reptiles, including dinosaurs and therefore birds) and synapsids (extinct pelycosaur, "pelycosaurs", therapsids and all extant mammals, including Homo sapiens, humans). Hox gene mutations have resulted in some tetrapods becoming Limbless vertebrate, limbless (snakes, legless lizards, and caecilians) or two-limbed (cetaceans, sirenians, Bipedidae, some lizards, kiwi (bird), kiwis, and the extinct moa and elephant birds). Nevertheless, they still qualify as tetrapods through their ancestry, and some retain a pair of ves ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Anatomy
Anatomy () is the branch of morphology concerned with the study of the internal structure of organisms and their parts. Anatomy is a branch of natural science that deals with the structural organization of living things. It is an old science, having its beginnings in prehistoric times. Anatomy is inherently tied to developmental biology, embryology, comparative anatomy, evolutionary biology, and phylogeny, as these are the processes by which anatomy is generated, both over immediate and long-term timescales. Anatomy and physiology, which study the structure and function of organisms and their parts respectively, make a natural pair of related disciplines, and are often studied together. Human anatomy is one of the essential basic sciences that are applied in medicine, and is often studied alongside physiology. Anatomy is a complex and dynamic field that is constantly evolving as discoveries are made. In recent years, there has been a significant increase in the use of ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cochlea
The cochlea is the part of the inner ear involved in hearing. It is a spiral-shaped cavity in the bony labyrinth, in humans making 2.75 turns around its axis, the modiolus (cochlea), modiolus. A core component of the cochlea is the organ of Corti, the sensory organ of hearing, which is distributed along the partition separating the fluid chambers in the coiled tapered tube of the cochlea. Etymology The name 'cochlea' is derived from the Latin word for ''snail shell'', which in turn is from the Greek language, Ancient Greek κοχλίας ''kokhlias'' ("snail, screw"), and from κόχλος ''kokhlos'' ("spiral shell") in reference to its coiled shape; the cochlea is coiled in mammals with the exception of monotremes. Structure The cochlea (: cochleae) is a spiraled, hollow, conical chamber of bone, in which waves propagate from the base (near the middle ear and the oval window) to the apex (the top or center of the spiral). The spiral canal of the cochlea is a section of the b ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cholesteatoma
Cholesteatoma is a destructive and expanding growth consisting of keratinizing squamous epithelium in the middle ear and/or mastoid process. Cholesteatomas are not cancerous as the name may suggest, but can cause significant problems because of their erosive and expansile properties. This can result in the destruction of the bones of the middle ear (ossicles), as well as growth through the base of skull, base of the skull into the brain. They often become infected and can result in chronically draining ears. Treatment almost always consists of surgical removal. Signs and symptoms Other more common conditions (e.g. otitis externa) may also present with these symptoms, but cholesteatoma is much more serious and should not be overlooked. If a patient presents to a doctor with ear discharge and hearing loss, the doctor should consider cholesteatoma until the disease is definitely excluded. Other less common symptoms (all less than 15%) of cholesteatoma may include pain, balance disorde ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
