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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] |
Schwartz Sign
Schwartz sign, also known as Flemingo's pink sign, is a diagnostic indicator for otosclerosis, a disease of the bones of the middle or inner ear. In clinical examination of the ear drum, increased vascularity of the promontory may be seen through the ear drum. This sign is known as Flemingo's flush sign or Schwartz's sign. This indicates otospongiosis (active otosclerosis). In about 10% of cases of 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 s ..., there is a redness of the promontory of the cochlea seen through the tympanic membrane due to prominent vascularity associated with an otospongiotic focus. Be aware of the similar, Brown's sign. This is a red retro-tympanic bulge that blanches on pressure via pneumatic otoscopy. This is secondary to paragangliomata of the ... [...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] |
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] |
Reelin
Reelin, encoded by the ''RELN'' gene, is a large secreted extracellular matrix glycoprotein that helps regulate processes of neuronal migration and positioning in the developing brain by controlling cell–cell interactions. Besides this important role in early Developmental biology, development, reelin continues to work in the adult brain. It modulates synaptic plasticity by enhancing the induction and maintenance of long-term potentiation. It also stimulates dendrite and dendritic spine development in the hippocampus, and regulates the continuing migration of neuroblasts generated in adult neurogenesis sites of the subventricular zone, subventricular and subgranular zones. It is found not only in the brain but also in the liver, Thyroid, thyroid gland, adrenal gland, fallopian tube, breast and in comparatively lower levels across a range of anatomical regions. Reelin has been suggested to be implicated in pathogenesis of several brain diseases. The expression of the protein has ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tinnitus
Tinnitus is a condition when a person hears a ringing sound or a different variety of sound when no corresponding external sound is present and other people cannot hear it. Nearly everyone experiences faint "normal tinnitus" in a completely quiet room; but this is of concern only if it is bothersome, interferes with normal hearing, or is associated with other problems. The word ''tinnitus'' comes from the Latin language, Latin ''wikt:en:tinnitus#Latin, tinnire'', "to ring." In some people, it interferes with concentration, and can be associated with anxiety and Depression (mood), depression. Tinnitus is usually associated with hearing loss and decreased comprehension of speech in noisy environments. It is common, affecting about 10–15% of people. Most tolerate it well, and it is a significant (severe) problem in only 1–2% of people. It can trigger a fight-or-flight response, as the brain may perceive it as dangerous and important. Rather than a disease, tinnitus is a sy ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hearing Loss
Hearing loss is a partial or total inability to hear. Hearing loss may be present at birth or acquired at any time afterwards. Hearing loss may occur in one or both ears. In children, hearing problems can affect the ability to acquire spoken language, and in adults it can create difficulties with social interaction and at work. Hearing loss can be temporary or permanent. Hearing loss related to age usually affects both ears and is due to cochlear hair cell loss. In some people, particularly older people, hearing loss can result in loneliness. Hearing loss may be caused by a number of factors, including: genetics, ageing, exposure to noise, some infections, birth complications, trauma to the ear, and certain medications or toxins. A common condition that results in hearing loss is chronic ear infections. Certain infections during pregnancy, such as cytomegalovirus, syphilis and rubella, may also cause hearing loss in the child. Hearing loss is diagnosed when hearing ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Audiogram
An audiogram is a graph that shows the audible threshold for standardized frequencies as measured by an audiometer. The Y axis represents intensity measured in decibels (dB) and the X axis represents frequency measured in hertz (Hz). The threshold of hearing is plotted relative to a standardised curve that represents 'normal' hearing, in dB(HL) (hearing level). They are not the same as equal-loudness contours, which are a set of curves representing equal loudness at different levels, as well as at the threshold of hearing, in absolute terms measured in dB(SPL) (sound pressure level). The frequencies displayed on the audiogram are octaves, which represent a doubling in frequency (e.g., 250 Hz, 500 Hz, 1000 Hz, wtc). Commonly tested "inter-octave" frequencies (e.g., 3000 Hz) may also be displayed. The intensities displayed on the audiogram appear as linear 10 dBHL steps. However, decibels are a logarithmic scale, so that successive 10 dB increments represent greater increases i ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bone Resorption
Bone resorption is resorption of bone tissue, that is, the process by which osteoclasts break down the tissue in bones and release the minerals, resulting in a transfer of calcium from bone tissue to the blood. The osteoclasts are multi-nucleated cells that contain numerous mitochondria and lysosomes. These are the cells responsible for the resorption of bone. Osteoblasts are generally present on the outer layer of bone, just beneath the periosteum. Attachment of the osteoclast to the osteon begins the process. The osteoclast then induces an infolding of its cell membrane and secretes collagenase and other enzymes important in the resorption process. High levels of calcium, magnesium, phosphate and products of collagen will be released into the extracellular fluid as the osteoclasts tunnel into the mineralized bone. Osteoclasts are prominent in the tissue destruction found in psoriatic arthritis and rheumatological disorders. The human body is in a constant state of bone re ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Autosomal Dominant
In genetics, dominance is the phenomenon of one variant (allele) of a gene on a chromosome masking or overriding the Phenotype, effect of a different variant of the same gene on Homologous chromosome, the other copy of the chromosome. The first variant is termed dominant and the second is called recessive. This state of having Heterozygosity, two different variants of the same gene on each chromosome is originally caused by a mutation in one of the genes, either new (''de novo'') or Heredity, inherited. The terms autosomal dominant or autosomal recessive are used to describe gene variants on non-sex chromosomes (autosomes) and their associated traits, while those on sex chromosomes (allosomes) are termed X-linked dominant, X-linked recessive or Y-linked; these have an inheritance and presentation pattern that depends on the sex of both the parent and the child (see Sex linkage). Since there is only one Y chromosome, Y-linked traits cannot be dominant or recessive. Additionally, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pure Tone Audiometry
Pure-tone audiometry is the main hearing test used to identify Hearing (sense), hearing threshold levels of an individual, enabling determination of the degree, type and configuration of a hearing loss and thus providing a basis for diagnosis and management. Pure-tone audiometry is a subjective, behavioural measurement of a hearing threshold, as it relies on patient responses to ''pure tone'' stimuli. Therefore, pure-tone audiometry is only used on adults and children old enough to cooperate with the test procedure. As with most clinical tests, standardized calibration of the test environment, the equipment and the stimuli is needed before testing proceeds (in reference to ISO, ANSI, or other standardization body). Pure-tone audiometry only measures audibility thresholds, rather than other aspects of hearing such as sound localization and speech recognition. However, there are benefits to using pure-tone audiometry over other forms of hearing test, such as click auditory brainst ... [...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] |
