A spiral tube that is firmly suspended in the bony shell-shaped part of the cochlea. This ENDOLYMPH-filled cochlear duct begins at the vestibule and makes 2.5 turns around a core of spongy bone (the modiolus) thus dividing the PERILYMPH-filled spiral canal into two channels, the SCALA VESTIBULI and the SCALA TYMPANI.
The spiral EPITHELIUM containing sensory AUDITORY HAIR CELLS and supporting cells in the cochlea. Organ of Corti, situated on the BASILAR MEMBRANE and overlaid by a gelatinous TECTORIAL MEMBRANE, converts sound-induced mechanical waves to neural impulses to the brain.
The essential part of the hearing organ consists of two labyrinthine compartments: the bony labyrinthine and the membranous labyrinth. The bony labyrinth is a complex of three interconnecting cavities or spaces (COCHLEA; VESTIBULAR LABYRINTH; and SEMICIRCULAR CANALS) in the TEMPORAL BONE. Within the bony labyrinth lies the membranous labyrinth which is a complex of sacs and tubules (COCHLEAR DUCT; SACCULE AND UTRICLE; and SEMICIRCULAR DUCTS) forming a continuous space enclosed by EPITHELIUM and connective tissue. These spaces are filled with LABYRINTHINE FLUIDS of various compositions.
A layer of stratified EPITHELIUM forming the endolymphatic border of the cochlear duct at the lateral wall of the cochlea. Stria vascularis contains primarily three cell types (marginal, intermediate, and basal), and capillaries. The marginal cells directly facing the ENDOLYMPH are important in producing ion gradients and endochoclear potential.
The part of the inner ear (LABYRINTH) that is concerned with hearing. It forms the anterior part of the labyrinth, as a snail-like structure that is situated almost horizontally anterior to the VESTIBULAR LABYRINTH.
The part of the membranous labyrinth that traverses the bony vestibular aqueduct and emerges through the bone of posterior cranial fossa (CRANIAL FOSSA, POSTERIOR) where it expands into a blind pouch called the endolymphatic sac.
Sensory cells in the organ of Corti, characterized by their apical stereocilia (hair-like projections). The inner and outer hair cells, as defined by their proximity to the core of spongy bone (the modiolus), change morphologically along the COCHLEA. Towards the cochlear apex, the length of hair cell bodies and their apical STEREOCILIA increase, allowing differential responses to various frequencies of sound.
Any of the processes by which nuclear, cytoplasmic, or intercellular factors influence the differential control of gene action during the developmental stages of an organism.
The channels that collect and transport the bile secretion from the BILE CANALICULI, the smallest branch of the BILIARY TRACT in the LIVER, through the bile ductules, the bile ducts out the liver, and to the GALLBLADDER for storage.
Ducts that collect PANCREATIC JUICE from the PANCREAS and supply it to the DUODENUM.

Altered cochlear fibrocytes in a mouse model of DFN3 nonsyndromic deafness. (1/43)

DFN3, an X chromosome-linked nonsyndromic mixed deafness, is caused by mutations in the BRN-4 gene, which encodes a POU transcription factor. Brn-4-deficient mice were created and found to exhibit profound deafness. No gross morphological changes were observed in the conductive ossicles or cochlea, although there was a dramatic reduction in endocochlear potential. Electron microscopy revealed severe ultrastructural alterations in cochlear spiral ligament fibrocytes. The findings suggest that these fibrocytes, which are mesenchymal in origin and for which a role in potassium ion homeostasis has been postulated, may play a critical role in auditory function.  (+info)

Essential role of BETA2/NeuroD1 in development of the vestibular and auditory systems. (2/43)

BETA2/NeuroD1 is a bHLH transcription factor that is expressed during development in the mammalian pancreas and in many locations in the central and peripheral nervous systems. During inner ear ontogenesis, it is present in both sensory ganglion neurons and sensory epithelia. Although studies have shown that BETA2/NeuroD1 is important in the development of the hippocampal dentate gyrus and the cerebellum, its functions in the peripheral nervous system and in particular in the inner ear are unclear. Mice carrying a BETA2/NeuroD1 null mutation exhibit behavioral abnormalities suggestive of an inner ear defect, including lack of responsiveness to sound, hyperactivity, head tilting, and circling. Here we show that these defects can be explained by a severe reduction of sensory neurons in the cochlear-vestibular ganglion (CVG). A developmental study of CVG formation in the null demonstrates that BETA2/NeuroD1 does not play a primary role in the proliferation of neuroblast precursors or in their decision to become neuroblasts. Instead, the reduction in CVG neuron number is caused by a combination both of delayed or defective delamination of CVG neuroblast precursors from the otic vesicle epithelium and of enhanced apoptosis both in the otic epithelium and among those neurons that do delaminate to form the CVG. There are also defects in differentiation and patterning of the cochlear duct and sensory epithelium and loss of the dorsal cochlear nucleus. BETA2/NeuroD1 is, thus, the first gene to be shown to regulate neuronal and sensory cell development in both the cochlear and vestibular systems.  (+info)

Spiral ligament pathology: a major aspect of age-related cochlear degeneration in C57BL/6 mice. (3/43)

Data from systematic, light microscopic examination of cochlear histopathology in an age-graded series of C57BL/6 mice (1.5-15 months) were compared with threshold elevations (measured by auditory brain stem response) to elucidate the functionally important structural changes underlying age-related hearing loss in this inbred strain. In addition to quantifying the degree and extent of hair cell and neuronal loss, all structures of the cochlear duct were qualitatively evaluated and any degenerative changes were quantified. Hair cell and neuronal loss patterns suggested two degenerative processes. In the basal half of the cochlea, inner and outer hair cell loss proceeded from base to apex with increasing age, and loss of cochlear neurons was consistent with degeneration occurring secondary to inner hair cell loss. In the apical half of the cochlea with advancing age, there was selective loss of outer hair cells which increased from the middle to the extreme apex. A similar gradient of ganglion cell loss was noted, characterized by widespread somatic aggregation and demyelination. In addition to these changes in hair cells and their innervation, there was widespread degeneration of fibrocytes in the spiral ligament, especially among the type IV cell class. The cell loss in the ligament preceded the loss of hair cells and/or neurons in both space and time suggesting that fibrocyte pathology may be a primary cause of the hearing loss and ultimate sensory cell degeneration in this mouse strain.  (+info)

Transcript profiling of functionally related groups of genes during conditional differentiation of a mammalian cochlear hair cell line. (4/43)

We have used Affymetrix high-density gene arrays to generate a temporal profile of gene expression during differentiation of UB/OC-1, a conditionally immortal cell line derived from the mouse cochlea. Gene expression was assessed daily for 14 days under differentiating conditions. The experiment was replicated in two separate populations of cells. Profiles for selected genes were correlated with those obtained by RT-PCR, TaqMan analysis, immunoblotting, and immunofluorescence. The results suggest that UB/OC-1 is derived from a population of nonsensory epithelial cells in the greater epithelial ridge that have the potential to differentiate into a hair-cell-like phenotype, without the intervention of Math1. Elements of the Notch signaling cascade were identified, including the receptor Notch3, with a transient up-regulation that suggests a role in hair cell differentiation. Several genes showed a profile similar to Notch3, including the transcriptional co-repressor Groucho1. UB/OC-1 also expressed Me1, a putative partner of Math1 that may confer competence to differentiate into hair cells. Cluster analysis revealed expression profiles for neural guidance genes associated with Gata3. The temporal dimension of this analysis provides a powerful tool to study genetic mechanisms that underlie the conversion of nonsensory epithelial cells into hair cells.  (+info)

Forced activation of Wnt signaling alters morphogenesis and sensory organ identity in the chicken inner ear. (5/43)

Components of the Wnt signaling pathway are expressed in the developing inner ear. To explore their role in ear patterning, we used retroviral gene transfer to force the expression of an activated form of beta-catenin that should constitutively activate targets of the canonical Wnt signaling pathway. At embryonic day 9 (E9) and beyond, morphological defects were apparent in the otic capsule and the membranous labyrinth, including ectopic and fused sensory patches. Most notably, the basilar papilla, an auditory organ, contained infected sensory patches with a vestibular phenotype. Vestibular identity was based on: (1) stereociliary bundle morphology; (2) spacing of hair cells and supporting cells; (3) the presence of otoliths; (4) immunolabeling indicative of vestibular supporting cells; and (5) expression of Msx1, a marker of certain vestibular sensory organs. Retrovirus-mediated misexpression of Wnt3a also gave rise to ectopic vestibular patches in the cochlear duct. In situ hybridization revealed that genes for three Frizzled receptors, c-Fz1, c-Fz7, and c-Fz10, are expressed in and adjacent to sensory primordia, while Wnt4 is expressed in adjacent, nonsensory regions of the cochlear duct. We hypothesize that Wnt/beta-catenin signaling specifies otic epithelium as macular and helps to define and maintain sensory/nonsensory boundaries in the cochlear duct.  (+info)

Distribution of gentamicin in the guinea pig inner ear after local or systemic application. (6/43)

Uptake and retention of gentamicin by cells in the guinea pig inner ear after a single peritoneal injection or local application on the round window were investigated using immunocytochemistry to localize the drug. The cells that accumulated the drug under the two conditions were the same, but staining for the drug was more intense and was often accompanied by widespread cochlear degeneration following local application. Soon after drug administration by either route, there was diffuse staining for the drug throughout all tissue within the labyrinth, including bone. At later times when distinct cell staining became evident, virtually all cell types were found to be positive, with several cell types staining more darkly for the drug than hair cells, indicating that hair cells were not the most avid in accumulating gentamicin. The infracuticular portion of auditory and vestibular hair cells as well as type III fibrocytes of the spiral ligament were positively stained in almost all cases and these sites were found to be positive for as long as six months post administration. In animals with loss of the organ of Corti, there was unusually intense staining for gentamicin in root cells of the spiral ligament, in marginal cells of the stria vascularis, and in cells of the spiral limbus. Dark staining of surviving cells in cases with overt tissue destruction suggests that variability in the extent of damage caused by the drug was determined more by the degree of its local uptake than by differences in animals' capacities to metabolize the drug systemically. The present results show that gentamicin may damage or destroy all cochlear cells following a single round window application. The findings broaden the scope of our knowledge of cochlear gentamicin uptake and damage and have implications for treatment of patients with vestibular disorders by infusion of aminoglycosides into the middle ear, as well as implications for prospects of rehabilitating patients that have been deafened by aminoglycosides.  (+info)

Changes in cytochemistry of sensory and nonsensory cells in gentamicin-treated cochleas. (7/43)

Effects of a single local dose of gentamicin upon sensory and nonsensory cells throughout the cochlea were assessed by changes in immunostaining patterns for a broad array of functionally important proteins. Cytochemical changes in hair cells, spiral ganglion cells, and cells of the stria vascularis, spiral ligament, and spiral limbus were found beginning 4 days post administration. The extent of changes in immunostaining varied with survival time and with cell type and was not always commensurate with the degree to which individual cell types accumulated gentamicin. Outer hair cells, types I and II fibrocytes of the spiral ligament, and fibrocytes in the spiral limbus showed marked decreases in immunostaining for a number of constituents. In contrast, inner hair cells, type III fibrocytes and root cells of the spiral ligament, cells of the stria vascularis, and interdental cells in the spiral limbus showed less dramatic decreases, and in some cases they showed increases in immunostaining. Results indicate that, in addition to damaging sensory cells, local application of gentamicin results in widespread and disparate disruptions of a variety of cochlear cell types. Only in the case of ganglion cells was it apparent that the changes in nonsensory cells were secondary to loss or damage of hair cells. These results indicate that malfunction of the ear following gentamicin treatment is widespread and far more complex than simple loss of sensory elements. The results have implications for efforts directed toward detecting, preventing, and treating toxic effects of aminoglycosides upon the inner ear.  (+info)

Synchronization of a nonlinear oscillator: processing the cf component of the echo-response signal in the cochlea of the mustached bat. (8/43)

Cochlear microphonic potential (CM) was recorded from the CF2 region and the sparsely innervated zone (the mustached bat's cochlea fovea) that is specialized for analyzing the Doppler-shifted echoes of the first-harmonic (approximately 61 kHz) of the constant-frequency component of the echolocation call. Temporal analysis of the CM, which is tuned sharply to the 61 kHz cochlear resonance, revealed that at the resonance frequency, and within 1 msec of tone onset, CM is broadly tuned with linear magnitude level functions. CM measured during the ongoing tone and in the ringing after tone offset is 50 dB more sensitive, is sharply tuned, has compressive level functions, and the phase leads onset CM by 90 degrees: an indication that cochlear responses are amplified during maximum basilar membrane velocity. For high-level tones above the resonance frequency, CM appears at tone onset and after tone offset. Measurements indicate that the two oscillators responsible for the cochlear resonance, presumably the basilar and tectorial membranes, move together in phase during the ongoing tone, thereby minimizing net shear between them and hair cell excitation. For tones within 2 kHz of the cochlear resonance the frequency of CM measured within 2 msec of tone onset is not that of the stimulus but is proportional to it. For tones just below the cochlear resonance region CM frequency is a constant amount below that of the stimulus depending on CM measurement delay from tone onset. The frequency responses of the CM recorded from the cochlear fovea can be accounted for through synchronization between the nonlinear oscillators responsible for the cochlear resonance and the stimulus tone.  (+info)

The cochlear duct, also known as the scala media, is a membranous duct located within the cochlea of the inner ear. It is one of three fluid-filled compartments in the cochlea, along with the vestibular duct (scala vestibuli) and the tympanic duct (scala tympani).

The cochlear duct contains endolymph, a specialized fluid that carries electrical signals to the auditory nerve. The organ of Corti, which is responsible for converting sound vibrations into electrical signals, is located within the cochlear duct.

The cochlear duct runs along the length of the cochlea and is separated from the vestibular duct by Reissner's membrane and from the tympanic duct by the basilar membrane. These membranes help to create a highly sensitive and selective environment for sound perception, allowing us to hear and distinguish different frequencies and intensities of sound.

The Organ of Corti is the sensory organ of hearing within the cochlea of the inner ear. It is a structure in the inner spiral sulcus of the cochlear duct and is responsible for converting sound vibrations into electrical signals that are sent to the brain via the auditory nerve.

The Organ of Corti consists of hair cells, which are sensory receptors with hair-like projections called stereocilia on their apical surfaces. These stereocilia are embedded in a gelatinous matrix and are arranged in rows of different heights. When sound vibrations cause the fluid in the cochlea to move, the stereocilia bend, which opens ion channels and triggers nerve impulses that are sent to the brain.

Damage or loss of hair cells in the Organ of Corti can result in hearing loss, making it a critical structure for maintaining normal auditory function.

The inner ear is the innermost part of the ear that contains the sensory organs for hearing and balance. It consists of a complex system of fluid-filled tubes and sacs called the vestibular system, which is responsible for maintaining balance and spatial orientation, and the cochlea, a spiral-shaped organ that converts sound vibrations into electrical signals that are sent to the brain.

The inner ear is located deep within the temporal bone of the skull and is protected by a bony labyrinth. The vestibular system includes the semicircular canals, which detect rotational movements of the head, and the otolith organs (the saccule and utricle), which detect linear acceleration and gravity.

Damage to the inner ear can result in hearing loss, tinnitus (ringing in the ears), vertigo (a spinning sensation), and balance problems.

Stria vascularis is a highly vascularized (rich in blood vessels) structure located in the cochlea of the inner ear. It plays a crucial role in the process of hearing by maintaining the endocochlear potential, which is essential for the conversion of sound waves into electrical signals that can be interpreted by the brain. The stria vascularis is composed of three layers: the marginal cells, intermediate cells, and basal cells, which work together to maintain the ionic balance and generate the endocochlear potential. Damage to the stria vascularis can result in hearing loss.

The cochlea is a part of the inner ear that is responsible for hearing. It is a spiral-shaped structure that looks like a snail shell and is filled with fluid. The cochlea contains hair cells, which are specialized sensory cells that convert sound vibrations into electrical signals that are sent to the brain.

The cochlea has three main parts: the vestibular canal, the tympanic canal, and the cochlear duct. Sound waves enter the inner ear and cause the fluid in the cochlea to move, which in turn causes the hair cells to bend. This bending motion stimulates the hair cells to generate electrical signals that are sent to the brain via the auditory nerve.

The brain then interprets these signals as sound, allowing us to hear and understand speech, music, and other sounds in our environment. Damage to the hair cells or other structures in the cochlea can lead to hearing loss or deafness.

The endolymphatic duct is a narrow canal in the inner ear that is part of the membranous labyrinth. It connects the utricle and saccule (two sensory structures in the vestibular system responsible for detecting changes in head position and movement) to the endolymphatic sac (a dilated portion of the duct that helps regulate the volume and pressure of endolymph, a fluid found within the membranous labyrinth).

The endolymphatic duct plays a crucial role in maintaining the balance and homeostasis of the inner ear by allowing the absorption and circulation of endolymph. Disorders or abnormalities in this region can lead to various vestibular and hearing dysfunctions, such as Meniere's disease, endolymphatic hydrops, and other inner ear disorders.

Auditory hair cells are specialized sensory receptor cells located in the inner ear, more specifically in the organ of Corti within the cochlea. They play a crucial role in hearing by converting sound vibrations into electrical signals that can be interpreted by the brain.

These hair cells have hair-like projections called stereocilia on their apical surface, which are embedded in a gelatinous matrix. When sound waves reach the inner ear, they cause the fluid within the cochlea to move, which in turn causes the stereocilia to bend. This bending motion opens ion channels at the tips of the stereocilia, allowing positively charged ions (such as potassium) to flow into the hair cells and trigger a receptor potential.

The receptor potential then leads to the release of neurotransmitters at the base of the hair cells, which activate afferent nerve fibers that synapse with these cells. The electrical signals generated by this process are transmitted to the brain via the auditory nerve, where they are interpreted as sound.

There are two types of auditory hair cells: inner hair cells and outer hair cells. Inner hair cells are the primary sensory receptors responsible for transmitting information about sound to the brain. They make direct contact with afferent nerve fibers and are more sensitive to mechanical stimulation than outer hair cells.

Outer hair cells, on the other hand, are involved in amplifying and fine-tuning the mechanical response of the inner ear to sound. They have a unique ability to contract and relax in response to electrical signals, which allows them to adjust the stiffness of their stereocilia and enhance the sensitivity of the cochlea to different frequencies.

Damage or loss of auditory hair cells can lead to hearing impairment or deafness, as these cells cannot regenerate spontaneously in mammals. Therefore, understanding the structure and function of hair cells is essential for developing therapies aimed at treating hearing disorders.

Developmental gene expression regulation refers to the processes that control the activation or repression of specific genes during embryonic and fetal development. These regulatory mechanisms ensure that genes are expressed at the right time, in the right cells, and at appropriate levels to guide proper growth, differentiation, and morphogenesis of an organism.

Developmental gene expression regulation is a complex and dynamic process involving various molecular players, such as transcription factors, chromatin modifiers, non-coding RNAs, and signaling molecules. These regulators can interact with cis-regulatory elements, like enhancers and promoters, to fine-tune the spatiotemporal patterns of gene expression during development.

Dysregulation of developmental gene expression can lead to various congenital disorders and developmental abnormalities. Therefore, understanding the principles and mechanisms governing developmental gene expression regulation is crucial for uncovering the etiology of developmental diseases and devising potential therapeutic strategies.

Bile ducts are tubular structures that carry bile from the liver to the gallbladder for storage or directly to the small intestine to aid in digestion. There are two types of bile ducts: intrahepatic and extrahepatic. Intrahepatic bile ducts are located within the liver and drain bile from liver cells, while extrahepatic bile ducts are outside the liver and include the common hepatic duct, cystic duct, and common bile duct. These ducts can become obstructed or inflamed, leading to various medical conditions such as cholestasis, cholecystitis, and gallstones.

The pancreatic ducts are a set of tubular structures within the pancreas that play a crucial role in the digestive system. The main pancreatic duct, also known as the duct of Wirsung, is responsible for transporting pancreatic enzymes and bicarbonate-rich fluid from the pancreas to the duodenum, which is the first part of the small intestine.

The exocrine portion of the pancreas contains numerous smaller ducts called interlobular ducts and intralobular ducts that merge and ultimately join the main pancreatic duct. This system ensures that the digestive enzymes and fluids produced by the pancreas are effectively delivered to the small intestine, where they aid in the breakdown and absorption of nutrients from food.

In addition to the main pancreatic duct, there is an accessory pancreatic duct, also known as Santorini's duct, which can sometimes join the common bile duct before emptying into the duodenum through a shared opening called the ampulla of Vater. However, in most individuals, the accessory pancreatic duct usually drains into the main pancreatic duct before entering the duodenum.

The cochlear duct houses the organ of Corti. The cochlear duct is part of the cochlea. It is separated from the tympanic duct ( ... Rarely, the cochlear duct may develop to have the wrong shape. Transverse section of the cochlear duct of a fetal cat. The ... The organ of Corti develops inside the cochlear duct. The cochlear duct contains the organ of Corti. This is attached to the ... The stria vascularis is located in the wall of the cochlear duct. The cochlear duct develops from the ventral otic vesicle ( ...
The stria vascularis of the cochlear duct is a capillary loop in the upper portion of the spiral ligament (the outer wall of ... The stria vascularis is part of the lateral wall of the cochlear duct. It is a somewhat stratified epithelium containing ... the cochlear duct). It produces endolymph for the scala media in the cochlea. ... cite book}}: ,work= ignored (help) Hopkins, Kathryn (2015). "27 - Deafness in cochlear and auditory nerve disorders". Handbook ...
Floor of cochlear duct. Spiral limbus and basilar membrane. Section through the spiral organ of Corti (magnified) The reticular ... Fay RR, Popper AN, Bacon SP (2004). Compression: From Cochlea to Cochlear Implants. Springer. ISBN 0-387-00496-3. Oghalai JS ( ... Salt AN, Konishi T (1986). "The cochlear fluids: Perilymph and endolymph.". In Altschuler RA, Hoffman DW, Bobbin RP (eds.). ... cite journal}}: Cite journal requires ,journal= (help) Nilsen KE, Russell IJ (July 1999). "Timing of cochlear feedback: spatial ...
The roof of the cochlear duct also has some. By ten days after birth the protein is not found in any cells, but only in the ... In mice the protein is first formed at day 9.5 in the otic vesicle dorsal wall epithelium, and also in the endolymphatic duct. ...
Pauw BK, Pollak AM, Fisch U (December 1991). "Utricle, saccule, and cochlear duct in relation to stapedotomy. A histologic ... Poor cochlear reserve as shown by poor speech discrimination scores Patient with tinnitus and vertigo Presence of active ... Presence of Carhart's notch in the audiogram of a patient with conductive hearing loss (relative) Good cochlear reserve as ... In particular, stapedotomy procedure greatly reduces the chance of a perilymph fistula (leakage of cochlear fluid). Stapedotomy ...
It separates the cochlear duct from the vestibular duct. It helps to transmit vibrations from fluid in the vestibular duct to ... The vestibular membrane separates the cochlear duct (scala media) from the vestibular duct (scala vestibuli). Histologically, ... The vestibular membrane helps to transmit vibrations from fluid in the vestibular duct to the cochlear duct. Together with the ... The vestibular membrane may be ruptured by an increase in the pressure of endolymph in the cochlear duct. This may occur in ...
The periosteum, forming the outer wall of the cochlear duct (Latin: ductus cochlearis), is greatly thickened and altered in ... Transverse section of the cochlear duct of a fetal cat. Diagrammatic longitudinal section of the cochlea. This article ...
It is separated from the cochlear duct by Reissner's membrane and extends from the vestibule of the ear to the helicotrema ... Transverse section of the cochlear duct of a fetal cat. Interior of right osseous labyrinth. Diagrammatic longitudinal section ... The vestibular duct or scala vestibuli is a perilymph-filled cavity inside the cochlea of the inner ear that conducts sound ... Tympanic duct Slide from University of Kansas Diagram at Indiana University - Purdue University Indianapolis Image at ...
Specifically, the cochlear duct growth and the formation of hair cells within the organ of Corti. Mutations in the genes ... Transverse section of the cochlear duct of a fetal cat. Diagrammatic longitudinal section of the cochlea Floor of ductus ... develops after the formation and growth of the cochlear duct. The inner and outer hair cells then differentiate into their ... The organ of Corti is located in the scala media of the cochlea of the inner ear between the vestibular duct and the tympanic ...
It is separated from the cochlear duct by the basilar membrane, and it extends from the round window to the helicotrema, where ... This movement is conveyed to the organ of Corti inside the cochlear duct, composed of hair cells attached to the basilar ... Transverse section of the cochlear duct of a fetal cat. The cochlea and vestibule, viewed from above. Diagrammatic longitudinal ... The purpose of the perilymph-filled tympanic duct and vestibular duct is to transduce the movement of air that causes the ...
The ventral component forms the saccule and the cochlear duct. In the sixth week of development the cochlear duct emerges and ... It remains connected to the cochlear duct via the narrow ductus reuniens. The dorsal component forms the utricle and ... Excretory tubules are formed and enter the mesonephric duct, which ends in the cloaca. The mesonephric duct atrophies in ... An outgrowth of the mesonephric duct, the ureteric bud, penetrates metanephric tissue to form the primitive renal pelvis, renal ...
Transverse section of the cochlear duct of a fetal cat. Floor of ductus cochlearis. Diagrammatic longitudinal section of the ... Cochlear implant Auditory Brainstem Response Palmer, A R (1987). "Physiology of the cochlear nerve and cochlear nucleus". ... the dorsal cochlear nucleus (DCN) the anteroventral cochlear nucleus (AVCN) the posteroventral cochlear nucleus (PVCN) Each of ... There, its fibers synapse with the cell bodies of the cochlear nucleus. In mammals, cochlear nerve fibers are classified as ...
They are in direct contact with the endolymph of the cochlear duct. These cells are sealed via tight junctions that prevent ...
The basilar crest lies within the cochlear duct in the inner ear. It gives attachment to the outer edge of the basilar membrane ...
... called the cochlear duct or scala media, contains endolymph. The organ of Corti is located in this duct on the basilar membrane ... Vestibular and tympanic ducts are filled with perilymph, and the smaller cochlear duct between them is filled with endolymph, a ... At the cochlear base the BM is at its narrowest and most stiff (high-frequencies), while at the cochlear apex it is at its ... the dorsal cochlear nucleus (DCN), and ventral cochlear nucleus (VCN). The VCN is further divided by the nerve root into the ...
The inner ear underwent multiple deformations affecting the cochlear duct, semicircular canals, and otic capsule portions. ... related deformity due to the absence of noggin is conductive hearing loss caused by uncontrolled outgrowth of the cochlear duct ...
It connects the lower part of the saccule to the cochlear duct near its vestibular extremity. Victor Hensen This article ...
The RM separates endolymph in the cochlear duct from underlying corticolymph and perilymph of the scala tympani. The hair ...
The cochlea consists of three fluid-filled spaces: the vestibular duct, the cochlear duct, and the tympanic duct. Hair cells ... Part of the saccule will eventually give rise and connect to the cochlear duct. This duct appears approximately during the ... membrane and the basilar membrane develop to separate the cochlear duct from the vestibular duct and the tympanic duct, ... As the cochlear duct's mesenchyme begins to differentiate, three cavities are formed: the scala vestibuli, the scala tympani ...
The basilar membrane separates the cochlear duct from the scala tympani, a cavity within the cochlear labyrinth. The lateral ... The hair cells develop from the lateral and medial ridges of the cochlear duct, which together with the tectorial membrane make ... Beginning in the fifth week of development, the auditory vesicle also gives rise to the cochlear duct, which contains the ... An endolymphatic duct runs from the saccule up through the head and ending close to the brain. In cartilaginous fish, this duct ...
... has a long cochlear duct, with the same height as the labyrinth, an adaptation to hearing low-frequency sounds. ...
The cochlea portion of the circuit uses a finite element analysis of the continuous transmission line of the cochlear duct. An ... Fukazawa, Tatsuya; Tanaka, Yasuo, "Evoked otoacoustic emissions in a cochlear model", pp. 191-196 in Hohmann, D. (ed), ECoG, ...
The cochlear duct is almost as complex on its own as the ear itself. The cochlear duct is bounded on three sides by the basilar ... The perilymph in the vestibular duct and the endolymph in the cochlear duct act mechanically as a single duct, being kept apart ... which lies inferior to the cochlear duct and terminates at the round window the cochlear duct or scala media (containing ... separates the cochlear duct from the tympanic duct and determines the mechanical wave propagation properties of the cochlear ...
The fluid found in these two cochlear chambers is perilymph, while scala media, or the cochlear duct, is filled with endolymph ... Cochlear hair cells are organized as inner hair cells and outer hair cells; inner and outer refer to relative position from the ... The apical surface of each cochlear hair cell contains a hair bundle. Each hair bundle contains approximately 300 fine ... Encoding shifts from synchronous responses in the cochlear nucleus and later becomes dependent on rate encoding in the inferior ...
The cochlear duct of the owl contains the basilar papilla, the tectorial membrane, the tegmentum vasculum, and the macula of ... the cochlear nucleus magnocellularis (mammalian anteroventral cochlear nucleus) and the cochlear nucleus angularis (see figure ... The fibers of the auditory nerve innervate both cochlear nuclei in the brainstem, ... mammalian posteroventral and dorsal cochlear nuclei). The neurons of the nucleus magnocellularis phase-lock, but are fairly ...
The semicircular canals are filled with endolymph due to its connection with the cochlear duct via the saccule, which also ... as well as the cochlear duct, which is involved in the special sense of hearing. ... The receptor cells located in the semicircular ducts are innervated by the eighth cranial nerve, the vestibulocochlear nerve ( ... Upon angular acceleration (rotation), the endolymph within the semicircular duct deflects the cupula against the hair cells of ...
There is also a long straight cochlear duct extending outwards, and a long cochlear duct typically indicates good hearing ... T. hydroides has a particularly large nasolacrimal duct, a tubular channel opening out of the rear of the lacrimal. The ...
... end of the otic vesicle gradually elongates as a tube and coils upon itself forming the beginnings of the cochlear duct. The ...
... the failure in the specification of prosensory domain and subsequently leads to increased cell death in the cochlear duct thus ...
The elongated cochlear ducts in the more advanced ankylosaurines seem to indicate that these traits were adapted for enhanced ... In addition, the length of the cochlear ducts in the inner ear suggests that Bissektipelta, and many other ankylosaurs, were ...
The cochlear duct houses the organ of Corti. The cochlear duct is part of the cochlea. It is separated from the tympanic duct ( ... Rarely, the cochlear duct may develop to have the wrong shape. Transverse section of the cochlear duct of a fetal cat. The ... The organ of Corti develops inside the cochlear duct. The cochlear duct contains the organ of Corti. This is attached to the ... The stria vascularis is located in the wall of the cochlear duct. The cochlear duct develops from the ventral otic vesicle ( ...
Maintenance of electrolyte content of the cochlear ducts. For many years, cochlear fluids were thought to be generated by ... Monitoring the Cochlear Response to an Acoustic Stimulus. Much of the data regarding cochlear function have been derived from ... Cochlear Blood Flow. The level of metabolic activity in the cochlea dictates the need for the maintenance of cochlear ... The differences in electrolyte contents of the cochlear ducts described above create chemical concentration gradients between ...
... the cochlear nuclei. Congenital and acquired neurosensory hearing loss affects millions of people worldwide. An increasing body ... cd, cochlear duct; HS, Hoechst nuclear staining; SVG, superior vestibular ganglion; and IVG, inferior vestibular ganglion. ... cd, cochlear duct; HS, Hoechst nuclear staining; SVG, superior vestibular ganglion; and IVG, inferior vestibular ganglion. ... The somata of auditory neurons form the spiral ganglion that twists within a coiled cochlear duct. Peripheral neuronal ...
After polymerization, the cochlear ducts were dissected into flat preparations & examined by phase-contrast microscopy. Grade 0 ...
S100 proteins are initially highly enriched throughout the cochlear duct at embryonic stages [38], and are later down-regulated ... expression of Fgfr1 appeared more intense at P0 relative to controls at basal and apical regions of the cochlear duct (Figure 1 ... but also the cell-specific differences in phosphorylated cofilin expression throughout the cochlear duct. Cofilin ... Phosphorylated Cofilin localizes to the cochlear sensory epithelium and is decreased in hypothyroid conditions. Representative ...
vestibular fissure of the cochlear canal vestibular labyrinth + vestibular membrane of cochlear duct ...
... individual adult cochleae were flat-mounted with the sensory epithelium facing up and the entire length of the cochlear duct ... To evaluate the cochlear phenotype of Neurod1cKO mutants, we stained cochlear whole mounts with antibody to Myo7a, a hair cell ... We evaluated DPOAE, as an objective measure of the function of the cochlear OHCs and cochlear amplification, using frequency ... Quantification of cochlear length at 4 weeks of age (n = 3). C, Sections of the CN immunostained with anti-NeuN (red) of adult ...
c. Cochlear duct[endolymph] d. Scala tympani [perilymph] Outer cochlear tunnel. e. Scala vestibuli [perilymph] Inner cochlear ...
... the dorsal vestibular apparatus and the ventral cochlear duct, required for motion and sound detection, respectively. Fgf10, in ... Fgf10 is required for specification of non-sensory regions of the cochlear epithelium. The vertebrate inner ear is a ...
The basilar membrane separates the cochlear duct from the scala tympani, a cavity within the cochlear labyrinth. The lateral ... The sense of hearing is provided by receptors within the cochlear duct. A pair of perilymph-filled chambers is found on each ... The hair cells develop from the lateral and medial ridges of the cochlear duct, which together with the tectorial membrane make ... Beginning in the fifth week of development, the auditory vesicle also gives rise to the cochlear duct, which contains the ...
The basilar membrane separates the cochlear duct from the scala tympani, a cavity within the cochlear labyrinth. The lateral ... The sense of hearing is provided by receptors within the cochlear duct. A pair of perilymph-filled chambers is found on each ... The hair cells develop from the lateral and medial ridges of the cochlear duct, which together with the tectorial membrane make ... Beginning in the fifth week of development, the auditory vesicle also gives rise to the cochlear duct, which contains the ...
RESULTS: In ears with MD, the saccule and the cochlear duct were most frequently hydropic; the utricle was involved ... CONCLUSION: Increases in endolymphatic pressure may cause a primary swelling of the apical cochlear duct and saccule, both of ...
COCHLEAR DUCT; SACCULE AND UTRICLE; and SEMICIRCULAR DUCTS) forming a continuous space enclosed by EPITHELIUM and connective ... Towards the cochlear apex, the length of hair cell bodies and their apical STEREOCILIA increase, allowing differential ...
cochlear duct (scala media) *organ of Corti (Spiral organ). *scala vestibuli. *scala tympani ...
As the cochlear ducts mesenchyme begins to differentiate, three cavities are formed: the scala vestibuli, the scala tympani ...
The cochlear duct is a triangular shaped duct which divides the cochlear canal of the into two canals; the scala vestibuli and ... Cochlea Duct. We are going to take a look at cross section of the cochlear to review the anatomy of the cochlea duct and ... Boundaries and Attachments of the Cochlea Duct. The cochlear duct is attached centrally to the bony spiral lamina of the ... The vestibule contains the utricle and the saccule as well as the basal end of the cochlear duct (cochlear recess). Within its ...
The measurements of cochlear basal turn on CT scan images were translated in cochlear duct length (CDL) values. Results. ... with GJB2 mutation etiology is different regarding cochlear size and cochlear duct (CDL) length when compared with SNHL ... Closing the cochlear apex gap in electrode insertion Cristian Mârţu1, Sebastian Cozma1, Adeline Josephine Cumpătă2, Alexandra ... Plenary demo of electrically-evoked auditory brainstem response in patients with a cochlear implant Andy J. Beynon Head ...
COCHLEAR DUCT AND ORGAN OF CORTI. Cochlear Duct and Organ of Corti 350X life size, composed of 5 parts. This model shows a ...
Using organotypic cultures of the chicken cochlear duct, we found that blocking VEGF receptor activity during hair cell injury ...
Also noted were shortened but widened bile ducts and disruption in canonical Wnt signaling. Using an in vitro wound closure ... We then discuss how the vertebrate processes of convergent extension and cochlear hair-cell development may relate to ... In successful Vangl2Lp/Lp outgrowths, three morphological phenotypes are observed: distended ducts, supernumerary end buds, and ... cochlear and congenital cardiac anomalies. Bj mutants die neonatally with cardiac outflow tract (OFT) malalignment. This is ...
It differentiates cochlear and retro-cochlear pathology. In cochlear lesion, stapedial reflex is present at lower intensities, ... Utricle and semicircular ducts are normal. Anomalies usually seen are:. *Marked dysplasia is seen in the membranous cochlea and ... vii) Cochlear/ vestibular nerve aplasia or malformation.. (viii) Semicircular canal malformations.Malformations are related to ... There is no role for hearing aids or cochlear implantation.. (v) Enlarged vestibular aqueduct. There is an enlargement of ...
Offer them the gift of sound with cochlear implant surgery by Dr. Meenesh Juvekar. Improve their hearing, speech, ... Duct Area Covering Pigeon Nets in Choolaimedu * B.Tech Distance Education in Chennai , SBIP ... Does your child have congenital hearing loss? Offer them the gift of sound with cochlear implant surgery by Dr. Meenesh Juvekar ... The Gift of Sound: Cochlear Implant Surgery for Congenital Hearing Loss * Submitted by entdoctormumbai ...
In 1921, he published his most famous work on the surgical treatment of cysts of the thyroglossal duct tract. He discovered the ... Treatment of the thyroglossal duct cyst was revolutionized by Walter Ellis Sistrunk, MD, of the Mayo Clinic in 1920 and the ... unchanged and is the gold standard for treatment of thyroglossal duct cysts. Dr. Sistrunk was also a consummate general surgeon ... The first is that there is a low general awareness of cochlear implants and their potential benefits by both the public as well ...
spiral o. [TA] a prominent ridge of highly specialized epithelium in the floor of the cochlear duct overlying the basilar ... the auditory receptor cells innervated by the cochlear nerve) supported by various columnar cells: the pillars of Corti, cells ... beginning just behind and above the incisive duct; a structure that usually regresses after the 6th month of gestation. In many ...
It lies within the petrous portion of the temporal bone and consists of bags and ducts of the membranous labyrinth. The ... The labyrinthine artery divides into: cochlear artery, for irrigation of the cochlea and vestibular arteries anterior and ...
The lateral (horizontal) ducts are in the identical in co rp o ra the s th e s o u n d tra n s m ittin g p ro p e rtie s o f ... There is likely a big unmet need for innovative interventions including reasonably priced hearing aids and probably cochlear ... the widespread bile duct and the pancreatic duct proportions. X-1 intraoperative complications in organ salvage operations on ... The higher end of the duct is made in the medial wall of the lacrimal sac to is curetted and the incision is closed by sutures ...
Ceilings double as air ducts, necessary technical joints between components serve as in- and outlets for ventilation and air ...
What to Expect After Getting Cochlear Implants. Following surgery for a cochlear implant, regular rehab is needed to help you ... Biliary atresia is a genetic condition in newborns where part or all of the bile duct is malformed. It requires prompt surgical ...
Cholangiocarcinoma see Bile Duct Cancer * Cholangitis see Bile Duct Diseases * Cholecystectomy see Gallbladder Diseases ... Cochlear Implants * Cold (Temperature) see Frostbite; Hypothermia; Winter Weather Emergencies * Cold and Cough Medicines ...
37165: Fretter V., - The genital ducts of Theodoxus, Lamellaria and Trivia, and a discussion on their evolution in the ... 62900: Fleischer G., - Hearing in extinct cetaceans as determined by cochlear structure. 61845: Fleischer L., - Rain Man, ... 72776: Freneix S., - Au sujet du phylum Neopycnodonte navicularis - Neopycnodonte cochlear. 73035: Freneix S., - Daonella ...
  • The cochlear duct (a.k.a. the scala media) is an endolymph filled cavity inside the cochlea, located between the tympanic duct and the vestibular duct, separated by the basilar membrane and the vestibular membrane (Reissner's membrane) respectively. (wikipedia.org)
  • It is separated from the vestibular duct (scala vestibuli) by the vestibular membrane (Reissner's membrane). (wikipedia.org)
  • The vertebrate inner ear is a morphologically complex sensory organ comprised of two compartments, the dorsal vestibular apparatus and the ventral cochlear duct, required for motion and sound detection, respectively. (utah.edu)
  • During week 4 of embryonic development, the human inner ear develops from the auditory placode, a thickening of the ectoderm that gives rise to the bipolar neurons of the cochlear and vestibular ganglions. (medscape.com)
  • The vestibular wall separates the cochlear duct from the perilymphatic scala vestibuli, a cavity inside the cochlea. (medscape.com)
  • Hypoplastic cochlear nerve and inferior division of vestibular nerve is seen. (entlecture.com)
  • There is no division between cochlear and vestibular parts. (entlecture.com)
  • The labyrinthine artery divides into: cochlear artery, for irrigation of the cochlea and vestibular arteries anterior and posterior semicircular canals to irrigate, utricle, saccule and part of the cochlea 8 . (bvsalud.org)
  • The cochlear duct is part of the cochlea. (wikipedia.org)
  • Drugs delivered directly to the tympanic duct will spread to all of the cochlea except for the cochlear duct. (wikipedia.org)
  • The cochlea consists of 3 fluid-filled ducts or scalae (see the image below). (medscape.com)
  • For many years, cochlear fluids were thought to be generated by filtration of blood or cerebrospinal fluid, which then flowed longitudinally down the length of the cochlea to be absorbed through the endolymphatic sac. (medscape.com)
  • The scala vestibuli extends from the oval window, travelling above the cochlear duct , which is the central cavity of the cochlea that contains the sound-transducing neurons. (lumenlearning.com)
  • At the uppermost tip of the cochlea, the scala vestibuli curves over the top of the cochlear duct. (lumenlearning.com)
  • The fluid-filled tube, now called the scala tympani , returns to the base of the cochlea, this time travelling under the cochlear duct. (lumenlearning.com)
  • A cross-sectional view of the cochlea shows that the scala vestibuli and scala tympani run along both sides of the cochlear duct (Figure 3. (lumenlearning.com)
  • These mice (both sexes) develop a truncated frequency range with no neuroanatomically recognizable mapping of spiral ganglion neurons onto distinct locations in the cochlea nor a cochleotopic map presenting topographically discrete projections to the cochlear nuclei. (jneurosci.org)
  • The cochlea is a bony, spiral-shaped chamber that contains the cochlear duct of the membranous labyrinth. (medscape.com)
  • The cochlea is this curved shell-like structure of the bony labyrinth which contains the cochlear duct , and is responsible for sound perception. (anatomyzone.com)
  • The cochlea duct which is part of the membranous labyrinth, is attached to the spiral lamina as it circles around the modiolus. (anatomyzone.com)
  • The cochlea duct attaches to the outer wall of the cochlea and creates two separate compartments - the scala vestibuli and the scala tympani which are continuous with each other within the cochlea apex via a narrow opening known as the helicotrema . (anatomyzone.com)
  • Beginning in the fifth week of development, the auditory vesicle also gives rise to the cochlear duct, which contains the spiral organ of Corti and the endolymph that accumulates in the membranous labyrinth. (medscape.com)
  • It lies within the petrous portion of the temporal bone and consists of bags and ducts of the membranous labyrinth. (bvsalud.org)
  • It is separated from the tympanic duct (scala tympani) by the basilar membrane. (wikipedia.org)
  • The organs of Corti lie on top of the basilar membrane , which is the side of the cochlear duct located between the organs of Corti and the scala tympani. (lumenlearning.com)
  • The basilar membrane separates the cochlear duct from the scala tympani, a cavity within the cochlear labyrinth. (medscape.com)
  • These neurons transmit auditory information in the form of electric signals from sensory hair cells to the first auditory nuclei of the brain stem, the cochlear nuclei. (mdpi.com)
  • It damages the cochlear nuclei and causes haemorrhage into the ear. (entlecture.com)
  • Bilirubin level greater than 20 mg% damages the cochlear nuclei. (entlecture.com)
  • The utricular division of the auditory vesicle also responds to angular acceleration, as well as the endolymphatic sac and duct that connect the saccule and utricle. (medscape.com)
  • CONCLUSION: Increases in endolymphatic pressure may cause a primary swelling of the apical cochlear duct and saccule, both of which have relatively thin membranes. (bvsalud.org)
  • The sense of hearing is provided by receptors within the cochlear duct. (medscape.com)
  • The semicircular canals enclose the slender semicircular ducts. (medscape.com)
  • Utricle and semicircular ducts are normal. (entlecture.com)
  • The cochlear duct develops from the ventral otic vesicle (otocyst). (wikipedia.org)
  • Mack KF, Heermann R, Issing PR, Lenarz T, Schwab B. Four years' experience with the minimally invasive surgical approach in cochlear implant surgery. (medscape.com)
  • Majdani O, Rau TS, Baron S, Eilers H, Baier C, Heimann B. A robot-guided minimally invasive approach for cochlear implant surgery: preliminary results of a temporal bone study. (medscape.com)
  • Offer them the gift of sound with cochlear implant surgery by Dr. Meenesh Juvekar. (bizzsubmit.com)
  • The lateral wall of the cochlear duct is formed by the spiral ligament and the stria vascularis, which produces the endolymph. (medscape.com)
  • The walls of the bony labyrinth consist of dense bone everywhere except at 2 small areas near the base of the cochlear spiral. (medscape.com)
  • cochlear labyrinth. (en-academic.com)
  • A pair of perilymph-filled chambers is found on each side of the duct. (medscape.com)
  • The round window consists of a thin, membranous partition that separates the perilymph of the cochlear chambers from the air-filled middle ear. (medscape.com)
  • The base of the modiolus is angled towards the internal auditory meatus where it receives branches of the cochlear nerve which arise from the 8th cranial nerve - the vestibulocochlear nerve. (anatomyzone.com)
  • Cochlear implantation has become a common method of rehabilitating severely to profoundly deaf children and adults. (medscape.com)
  • Standard cochlear implantation requires an extended postauricular and scalp incision and large flap, mastoidectomy , facial recess approach, cochleostomy, and insertion of an electrode into the scala tympani. (medscape.com)
  • The most common complications associated with the standard approach to cochlear implantation include flap breakdown and electrode misplacement. (medscape.com)
  • In recent years, the standard approach to cochlear implantation with a large incision has been challenged by successful implantation of cochlear implants in numerous patients with a much smaller incision and a less-invasive approach. (medscape.com)
  • Complication rate of minimally invasive cochlear implantation. (medscape.com)
  • Mann WJ, Gosepath J. Technical Note: minimal access surgery for cochlear implantation with MED-EL devices. (medscape.com)
  • Soft tissue complications after small incision pediatric cochlear implantation. (medscape.com)
  • Majdani O, Bartling SH, Leinung M, Stöver T, Lenarz M, Dullin C. A true minimally invasive approach for cochlear implantation: high accuracy in cranial base navigation through flat-panel-based volume computed tomography. (medscape.com)
  • There is no role for hearing aids or cochlear implantation. (entlecture.com)
  • An image depicting the divisions and electrolyte compositions of the cochlear compartments can be seen below. (medscape.com)
  • The divisions and electrolyte compositions of the cochlear compartments. (medscape.com)
  • Sound is transduced into neural signals within the cochlear region of the inner ear, which contains the sensory neurons of the spiral ganglia . (lumenlearning.com)
  • The hair cells develop from the lateral and medial ridges of the cochlear duct, which together with the tectorial membrane make up the spiral organ of Corti. (medscape.com)
  • The spiral canal of the cochlear begins at the vestibule and makes 2 and half turns around a central conical core of spongy bone known as the modiolus . (anatomyzone.com)
  • The stria vascularis is located in the wall of the cochlear duct. (wikipedia.org)
  • The base of the cochlear, or the basal turn , forms the cochlear promontory which in turn forms the medial wall of the middle ear compartment (see video on boundaries of the middle ear for further details). (anatomyzone.com)
  • The basal turn of the cochlear is connected with the subarachnoid space of the posterior cranial fossa with an opening just superior to the jugular foramen via the cochlear aqueduct . (anatomyzone.com)
  • La empresa y toda su organización debe estar ligada al canal de comercio electronico para atender y manejar cada una de las ordenes como si fuera hecha en una tienda fisica. (blog-top.com)
  • Esta el inventario acorde con las existencias en el canal electrónico? (blog-top.com)
  • Campisi P, Hayward L, Papsin B. Mitek QuickAnchor fixation of cochlear implants using a minimal access technique. (medscape.com)
  • Early identification can help to make early decisions about hearing rehabilitation including hearing aids, and cochlear implants. (entlecture.com)
  • In 1921, he published his most famous work on the surgical treatment of cysts of the thyroglossal duct tract. (entnet.org)
  • Labadie RF, Chodhury P, Cetinkaya E, Balachandran R, Haynes DS, Fenlon MR. Minimally invasive, image-guided, facial-recess approach to the middle ear: demonstration of the concept of percutaneous cochlear access in vitro. (medscape.com)
  • Rarely, the cochlear duct may develop to have the wrong shape. (wikipedia.org)
  • Since that time, the procedure has remained, for the most part, unchanged and is the gold standard for treatment of thyroglossal duct cysts. (entnet.org)
  • Magnetic resonance cholangiopancreatography (MRCP) is particularly valuable as a noninvasive, highly accurate method of imaging the biliary and pancreatic duct systems. (msdmanuals.com)