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Secondary Tympanic Membrane
The round window is one of the two openings from the middle ear into the inner ear. It is sealed by the secondary tympanic membrane (round window membrane), which vibrates with opposite phase to vibrations entering the inner ear through the oval window. It allows fluid in the cochlea to move, which in turn ensures that hair cells of the basilar membrane will be stimulated and that audition will occur. Structure The round window is situated below (inferior to) and a little behind (posterior to) the oval window, from which it is separated by a rounded elevation, the promontory. It is located at the bottom of a funnel-shaped depression (the round window niche) and, in the macerated bone, opens into the cochlea of the internal ear; in the fresh state it is closed by a membrane, the secondary tympanic membrane (, or ) or round window membrane, which is a complex saddle point shape. The visible central portion is concave (curved inwards) toward the tympanic cavity and convex (curved ... [...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] |
Stapes
The ''stapes'' or stirrup is a bone in the middle ear of humans and other tetrapods 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, which allows the footplate (or base) to transmit sound energy through the oval window into the inner ear. The ''stapes'' is the smallest and lightest bone in the human body, and is so-called because of its resemblance to a stirrup (). Structure The ''stapes'' is the third bone of the three ossicles in the middle ear and the smallest in the human body. It measures roughly , greater along the head-base span. It rests on the oval window, to which it is connected by an annular ligament and articulates with the ''incus'', or anvil through the incudostapedial joint. They are connected by anterior and posterior limbs (). Development The ''stapes'' develops from the second pharyngeal arch during the sixth to eighth week of embryological life. The central ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
University Of Denver
The University of Denver (DU) is a private research university in Denver, Colorado, United States. Founded in 1864, it has an enrollment of approximately 5,700 undergraduate students and 7,200 graduate students. It is classified among "R1: Doctoral Universities – Very high research activity". The main campus is a designated arboretum and is located five miles (8 km) south of downtown Denver. History In March 1864, John Evans, former governor of the Colorado Territory, appointee of President Abraham Lincoln, founded the Colorado Seminary in the newly created (1858) city of Denver, which was then a mining camp. Evans, governor and superintendent of Indian affairs of the Colorado Territory, lost his government position as a result of the November 1864 Sand Creek massacre (which was carried out by Colonel John Chivington, later a member of the Colorado Seminary's Trustees). At its founding the seminary was non-sectarian and operated by the Methodist Episcopal Chur ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Southwest Tennessee Community College
Southwest Tennessee Community College is a public community college in Memphis, Tennessee. As the product of a merger between two colleges in 2000, the school has two campuses in Memphis and several satellite centers. The Tennessee Board of Regents operates it. History The college resulted from the 2000 merger between two institutions, the former Shelby State Community College and the former State Technical Institute at Memphis ("STIM"). Nathan Essex, the school's founding president, announced in 2014 that he would retire the next summer. Campuses Southwest throughout the Mid-South: *Macon Cove Campus- located in Northeast Memphis () *Union Avenue Campus- located in Downtown Memphis () ** Medical District High School is located in Building E. * Maxine A. Smith Center- located in Southeast Memphis *Millington Center- located in Millington, Tennessee *Whitehaven Center- located in Whitehaven Southwest previously had a campus located in Frayser but sold it to Libertas Schoo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Oval Window
The oval window (or ''fenestra vestibuli'' or ''fenestra ovalis'') is a connective tissue membrane-covered opening from the middle ear to the cochlea of the inner ear. Vibrations that contact the tympanic membrane travel through the three ossicles and into the inner ear. The oval window is the intersection of the middle ear with the inner ear and is directly contacted by the stapes; by the time vibrations reach the oval window, they have been reduced in amplitude and increased in pressure due to the lever action of the ossicle bones. This is not an amplification function; rather, an impedance-matching function, allowing sound to be transferred from air (outer ear) to liquid (cochlea). It is a reniform (kidney-shaped) opening leading from the tympanic cavity into the vestibule of the inner ear; its long diameter is horizontal and its convex border is upward. It is occupied by the base of the ''stapes'', the circumference of which is fixed by the annular ligament to the margin of ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Verona
Verona ( ; ; or ) is a city on the Adige, River Adige in Veneto, Italy, with 255,131 inhabitants. It is one of the seven provincial capitals of the region, and is the largest city Comune, municipality in the region and in Northeast Italy, northeastern Italy. The metropolitan area of Verona covers an area of and has a population of 714,310 inhabitants. It is one of the main tourist destinations in Northern Italy because of its artistic heritage and several annual fairs and shows as well as the Opera, opera season in the Verona Arena, Arena, an ancient Ancient Rome, Roman Amphitheatre, amphitheater. Between the 13th and 14th centuries, the city was ruled by the Scaliger, della Scala family. Under the rule of the family, in particular of Cangrande I della Scala, the city experienced great prosperity, becoming rich and powerful and being surrounded by new walls. The della Scala era is preserved in numerous monuments around Verona. Two of William Shakespeare's plays are set in Ve ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cochlear Implant
A cochlear implant (CI) is a surgically implanted Neuroprosthetics, neuroprosthesis that provides a person who has moderate-to-profound sensorineural hearing loss with sound perception. With the help of therapy, cochlear implants may allow for improved speech understanding in both quiet and noisy environments. A CI bypasses acoustic hearing by direct electrical stimulation of the auditory nerve. Through everyday listening and auditory training, cochlear implants allow both children and adults to learn to interpret those signals as speech and sound. The implant has two main components. The outside component is generally worn behind the ear, but could also be attached to clothing, for example, in young children. This component, the sound processor, contains microphones, electronics that include digital signal processor (DSP) chips, battery, and a coil that transmits a signal to the implant across the skin. The inside component, the actual implant, has a coil to receive signals, elect ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Computed Tomography Of The Head
Computed tomography of the head uses a series of X-rays in a CT scan of the head taken from many different directions; the resulting data is transformed into a series of cross sections of the brain using a computer program. CT images of the head are used to investigate and diagnose brain injuries and other neurological conditions, as well as other conditions involving the skull or sinuses; it used to guide some brain surgery procedures as well. CT scans expose the person getting them to ionizing radiation which has a risk of eventually causing cancer; some people have allergic reactions to contrast agents that are used in some CT procedures. Uses Computed tomography (CT) has become the diagnostic modality of choice for head trauma due to its accuracy, reliability, safety, and wide availability. The changes in microcirculation, impaired auto-regulation, cerebral edema, and axonal injury start as soon as head injury occurs and manifest as clinical, biochemical, and radiological cha ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Vestibule Of The Ear
The vestibule is the central part of the bony labyrinth in the inner ear, and is situated medial to the eardrum, behind the cochlea, and in front of the three semicircular canals. The name comes from the Latin ', literally an entrance hall. Structure The vestibule is somewhat oval in shape, but flattened transversely; it measures about 5 mm from front to back, the same from top to bottom, and about 3 mm across. In its lateral or tympanic wall is the oval window, closed, in the fresh state, by the base of the stapes and annular ligament. On its medial wall, at the forepart, is a small circular depression, the recessus sphæricus, which is perforated, at its anterior and inferior part, by several minute holes (macula cribrosa media) for the passage of filaments of the acoustic nerve to the saccule; and behind this depression is an oblique ridge, the crista vestibuli, the anterior end of which is named the pyramid of the vestibule. This ridge bifurcates below to e ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Otosclerosis
Otosclerosis is a condition of the middle ear, middle and inner ear where portions of the dense enchondral layer of the bony labyrinth Tissue remodeling, remodel into one or more lesions of irregularly-laid spongy bone. As the lesions reach the stapes the bone is Bone resorption, resorbed, then hardened (Sclerosis (medicine), sclerotized), which limits its movement and results in hearing loss, tinnitus, vertigo or a combination of these. The term otosclerosis is something of a misnomer: much of the clinical course is characterized by lucent rather than sclerotic bony changes, so the disease is also known as otospongiosis. Etymology The word ''otosclerosis'' derives from Greek Language, Greek ὠτός (''ōtos''), genitive of οὖς (''oûs'') "ear" + σκλήρωσις (''sklērōsis''), "hardening". Presentation The primary form of hearing loss in otosclerosis is conductive hearing loss (CHL) whereby sounds reach the ear drum but are incompletely transferred via the ossicular ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Decibel
The decibel (symbol: dB) is a relative unit of measurement equal to one tenth of a bel (B). It expresses the ratio of two values of a Power, root-power, and field quantities, power or root-power quantity on a logarithmic scale. Two signals whose level (logarithmic quantity), levels differ by one decibel have a power ratio of 101/10 (approximately ) or root-power ratio of 101/20 (approximately ). The strict original usage above only expresses a relative change. However, the word decibel has since also been used for expressing an Absolute scale, absolute value that is relative to some fixed reference value, in which case the dB symbol is often suffixed with letter codes that indicate the reference value. For example, for the reference value of 1 volt, a common suffix is "#Voltage, V" (e.g., "20 dBV"). As it originated from a need to express power ratios, two principal types of scaling of the decibel are used to provide consistency depending on whether the scaling refer ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hair Cells
Hair cells are the sensory receptors of both the auditory system and the vestibular system in the ears of all vertebrates, and in the lateral line organ of fishes. Through mechanotransduction, hair cells detect movement in their environment. In mammals, the auditory hair cells are located within the spiral organ of Corti on the thin basilar membrane in the cochlea of the inner ear. They derive their name from the tufts of stereocilia called ''hair bundles'' that protrude from the apical surface of the cell into the fluid-filled cochlear duct. The stereocilia number from fifty to a hundred in each cell while being tightly packed together and decrease in size the further away they are located from the kinocilium. Mammalian cochlear hair cells are of two anatomically and functionally distinct types, known as outer, and inner hair cells. Damage to these hair cells results in decreased hearing sensitivity, and because the inner ear hair cells cannot regenerate, this dam ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
