Fact-checked by Grok 2 weeks ago

Saccule

The saccule, also known as the sacculus, is a small, sac-like membranous structure within the vestibular of the , serving as one of two primary organs alongside the utricle and playing a crucial role in detecting linear and gravitational forces to maintain and spatial . Located in the vestibule between the and the , the saccule consists of a sensory called the , which is a vertically oriented patch of specialized cells embedded in a gelatinous matrix topped by an otolithic membrane containing dense crystals known as otoconia. These otoconia, each approximately 1–20 micrometers in size, impart weight to the membrane, enabling it to shear against the bundles during head movements or tilts, thereby deflecting the and kinocilia to generate receptor potentials that signal vestibular information via the eighth cranial to the . Primarily sensitive to vertical linear accelerations—such as up-down motions or forward-backward shifts—the saccule complements the horizontally oriented utricle by providing sensory input on head position relative to , essential for reflexes like the vestibulo-ocular and vestibulospinal responses that stabilize and posture during dynamic activities. In humans and other mammals, the saccule contains roughly 16,000–20,000 cells, with afferent innervation from neurons whose bodies lie in the vestibular , ensuring precise of mechanical stimuli into neural signals for . While its core function is vestibular, the saccule exhibits some auditory sensitivity in certain like , though in mammals this role is minimal compared to the .

Anatomy and Structure

Location and Orientation

The saccule is situated in the of the , inferior to the utricle and oriented roughly vertically in humans. It connects to the utricle via the utriculosaccular duct and drains into the endolymphatic duct through the saccular duct. In the anatomical position, the saccular faces posterolaterally and lies to the utricular macula, a configuration that positions it at approximately 90 degrees relative to the utricle. This orientation places the saccule within a spherical recess of the , with its superior wall adhering to the utricle's floor. In non-human vertebrates such as , the saccule is oriented vertically in the , aligning with the body's longitudinal axis to facilitate detection of gravitational forces for regulation.

Macroscopic Features

The saccule is a small, sac-like membranous structure within the . Its ovoid shape distinguishes it from the more elongated utricle, forming part of the suspended within the bony . The interior of the saccule is filled with , a potassium-rich fluid that maintains the ionic environment necessary for sensory function, while it is externally bathed in , which approximates composition and provides mechanical support. This dual-fluid arrangement isolates the delicate membranous components from the surrounding bony structures of the . Prominent macroscopic features include the saccular duct, also known as the ductus reuniens, which connects the saccule to the cochlear duct at the base of the , allowing fluid communication between the vestibular and auditory systems. Additionally, the anterior wall exhibits a noticeable bulge corresponding to the sacculi, an elliptical thickening visible on gross examination that houses sensory elements oriented vertically. Size and proportions of the saccule exhibit variations across mammalian species, with aquatic forms such as cetaceans displaying relatively enlarged organs, including the saccule, to enhance detection of gravitational forces and linear accelerations in submerged environments. These adaptations support balance during constant underwater motion.

Microscopic Components

The macula sacculi serves as the primary sensory within the saccule, comprising a specialized neuroepithelium lined with sensory cells and interspersed supporting cells. This features two main types of cells: type I hair cells, which are flask-shaped and enveloped by a for enhanced synaptic efficiency, and type II hair cells, which are cylindrical and form ribbon synapses with multiple afferent fibers. These cells are embedded within a gelatinous otolithic that provides and facilitates mechanotransduction. Overlying the cells in the sacculi are otoliths, also known as statoconia, which consist of numerous small . These crystalline structures, embedded in the gelatinous matrix, impart significant inertial mass to the sensory apparatus, enabling to gravitational and linear forces. Supporting cells within the sacculi include pillar-like cells that contribute to the architectural organization of the and dark cells located at the margins, which are specialized for active and maintenance of endolymphatic through high secretion. Afferent fibers from the vestibular division of cranial nerve VIII innervate both type I and type II cells, transmitting sensory signals to the . The striola region, a central band within the , exhibits a notably higher of cells compared to peripheral areas and features bidirectional patterns, where adjacent cells orient their kinocilia in opposite directions to optimize directional .

Function and Physiology

Detection of Linear Acceleration

The saccule primarily detects linear accelerations in the vertical , corresponding to up-down head movements, through its specialized sensory known as the macula sacculi. This organ is oriented such that its macula is vertically in a approximately parallel to the , making it sensitive to gravitational forces and inertial accelerations primarily in the vertical direction (up-down) and along the rostrocaudal axis (fore-aft). The sensitivity threshold for detecting these linear accelerations is approximately 0.01 , allowing the saccule to respond to subtle changes in head position relative to or during vertical motion. Within the saccule, type I and type II s transduce mechanical stimuli into electrical signals via their , which are embedded in a gelatinous otolithic overlaid with crystals called otoliths. During vertical linear acceleration or static head tilt, the of the otoliths causes a shearing relative to the underlying hair cells, bending the bundle either toward or away from the tallest stereocilium, known as the . This deflection depolarizes the hair cell when stereocilia bend toward the kinocilium, increasing release, or hyperpolarizes it when bending in the opposite direction, thereby modulating afferent nerve activity in a directionally sensitive manner. The process in saccular s involves the opening of mechanosensitive ion channels at the tips of the , primarily composed of transmembrane channel-like proteins TMC1 and TMC2, which form the pore of the transduction complex. Bending of the gates these channels, permitting an influx of ions from the high-potassium into the , which generates a due to the . TMC1 and TMC2 contribute to the channel's conductance properties, with TMC2 enabling higher single-channel currents (approximately 100 pS) in vestibular s compared to TMC1 (around 50 pS), ensuring robust sensitivity to linear forces in the saccule. Neural coding in the saccule relies on the tonic modulation of afferent firing rates from the , where primary afferents innervating the exhibit sustained discharge that varies proportionally with the shear forces exerted by displacement. This tonic response encodes both dynamic accelerations and static tilts, providing a continuous signal of vertical linear forces, in contrast to the phasic-tonic patterns observed in semicircular canal afferents for angular motion. Regular afferents from the saccular , often originating from type II hair cells, maintain this tonic firing to support ongoing of gravitational orientation and .

Integration in the Vestibular System

Saccular afferents, which carry sensory information from the saccule, travel through the inferior and project primarily to the in the . These projections terminate strongly in the lateral and inferior , with additional collaterals extending to the for further processing. This pathway allows saccular signals, encoding linear accelerations and head tilts, to integrate into central vestibular networks that support and spatial awareness. Within these nuclei, saccular inputs contribute to key reflex pathways, including the (VOR), which stabilizes gaze during linear head movements. The saccule, as part of the otolith organs, detects translational accelerations and head position relative to gravity, enabling the translational VOR (t-VOR) to generate compensatory eye movements that maintain visual fixation on targets. Saccular signals also feed into the vestibulo-spinal reflex via the , facilitating postural adjustments by activating extensor muscles in the limbs and trunk to counteract body sway induced by linear perturbations. Bilateral saccular inputs converge in the , where neurons process combined signals from both sides to discern net linear accelerations and enhance spatial orientation. This convergence, often alongside and inputs, allows central vestibular neurons to encode three-dimensional motion vectors, distinguishing true translation from gravitational tilts for precise postural and oculomotor control. In the , saccular signals interact with proprioceptive inputs from muscle spindles and joint receptors, as well as visual cues from the optic flow, to form a multisensory framework for processing. neurons integrate these modalities, weighting them dynamically based on reliability—such as prioritizing in stable environments or vestibular/proprioceptive signals during rapid movements—to optimize upright and prevent falls. This integration occurs primarily in the and extends to higher centers like the , ensuring coordinated responses to environmental demands.

Auditory Contributions

The saccule exhibits sensitivity to acoustic stimuli, particularly low-frequency sounds transmitted via , where vibrations activate its cells in a manner analogous to linear detection. This response is most pronounced for frequencies around 200–500 Hz, though it extends to lower ranges below 100 Hz in certain contexts, contributing to the processing of infrasonic or vibrational auditory cues. This auditory sensitivity is assessed through vestibular evoked myogenic potentials (VEMPs), specifically cervical VEMPs (cVEMPs), which elicit myogenic responses from the following saccular activation. A standard stimulus for this is a 500 Hz tone-burst delivered at high intensity (typically 90–100 dB nHL), producing reliable evoked potentials that reflect saccular function in response to sound. These potentials provide a non-invasive measure of the saccule's acoustic responsiveness, distinct from its primary vestibular role. The saccule's auditory capabilities represent an evolutionary remnant from ancestral vertebrates, where in , the saccule served as a primary for hearing and detection, processing underwater for tasks like predator avoidance. In humans, this heritage persists as a subsidiary function, potentially aiding in the localization of low-frequency sounds through bone-conducted pathways, especially in scenarios where cochlear hearing is compromised, such as in profound . Auditory signals from the saccule travel primarily via the vestibular division of the eighth cranial nerve (), specifically the inferior vestibular branch, projecting to the in the . While this pathway overlaps anatomically with the cochlear auditory route—sharing the vestibulocochlear nerve trunk—saccular inputs remain predominantly vestibular, integrating with auditory processing centers for multimodal sensory encoding without direct cochlear dominance.

Development and Evolution

Embryological Development

The saccule originates from the ventral portion of the otic placode, an ectodermal thickening that appears dorsolateral to the during the fourth week of . This placode invaginates to form the otic pit and subsequently the otic vesicle (otocyst) by the end of week 4, with the ventral region differentiating into the saccular diverticulum around week 6, marking the initial partitioning from the dorsal utricular component. This early ventral evagination establishes the foundational structure that will mature into the saccule, a key component of the within the adult . By the eighth week of , the sacculi begins to form within the saccular , consisting of sensory with differentiating cells and supporting cells. differentiation in this region is regulated by transcription factors such as Pax2 and , which are expressed in prosensory progenitors derived from PAX2/PAX8-positive otic epithelial cells, promoting the specification and maintenance of these mechanosensory elements. , in particular, sustains progenitor proliferation and supports the transition to differentiated hair cells in the vestibular sensory patches, including the saccule, during this critical period. Otolith formation in the saccule commences around week 8, with otoconia precursors secreted by dark cells in the , leading to the deposition of crystals within the otolithic membrane overlying the sacculi. These dark cells, analogous to those in the utricle, contribute to production and . Concurrently, innervation of the saccule by neurons from the occurs progressively from weeks 6 to 8, with fibers extending into the sensory and forming initial synaptic contacts by week 12. Disruptions in the early partitioning of the otic vesicle, particularly around weeks 6 to 7, can lead to congenital anomalies such as Mondini dysplasia, characterized by incomplete cochlear partitioning (1.5 turns), an enlarged vestibule, and large , often resulting in reduced hair cells in the saccular macula and associated . This malformation arises from around week 7, highlighting the vulnerability of otic vesicle partitioning to genetic or environmental factors during embryogenesis.

Evolutionary Origins

The saccule evolved from primitive mechanosensory structures shared with the fish lateral line system, which detects water movements, with both systems deriving from common ectodermal placodes in early vertebrates approximately 500 million years ago during the period. This adaptation enabled gravity detection through hair cells and rudimentary otoliths, marking a shift from simple statocyst-like organs in to more specialized vestibular components. In jawless vertebrates such as lampreys, the saccule manifests as a basic gravity sensor featuring two ciliated chambers and otoconia for orientation in aquatic environments, reflecting its ancestral role in linear acceleration sensing without complex . As vertebrates transitioned to tetrapods during the period around 375 million years ago, the saccule specialized for vertical sensing to support , with otoliths providing enhanced sensitivity compared to the less precise statoliths in jellyfish-like statocysts of earlier . Fossil evidence from fish reveals early vestibular diversification, indicating the emergence of dedicated otolithic organs for amid the shift to land. These adaptations allowed tetrapods to maintain postural stability against , evolving from pressure detection to precise tilt perception. Comparative anatomy across tetrapod lineages highlights further specializations: in and reptiles, the saccular macula is often elongated along the anterior-posterior axis to aid in stabilizing flight or agile movement, with supporting type hair cells enhancing responsiveness. Mammalian saccules, in contrast, feature denser otoconial layers that improve gravitational resolution, as seen in the more compact and efficient vestibular structures of . In modern humans, these evolutionary refinements contribute to upright and bipedal .

Clinical Significance

Associated Pathologies

(SCDS) can lead to enhanced vestibular evoked myogenic potentials (VEMPs) indicating altered sensitivity to sound and pressure, though it primarily affects the superior semicircular canal and superior ; isolated saccular impairment is not typical. This condition often leads to vertigo triggered by activities that alter intracranial or intratympanic pressure, contributing to disequilibrium and sound- or pressure-induced vertigo. Meniere's disease is characterized by endolymphatic hydrops in the , resulting in distension of the saccular membrane due to excess accumulation from impaired or . This hydrops disrupts normal otolithic function, manifesting as episodic vertigo attacks lasting minutes to hours, accompanied by aural fullness and fluctuating . In severe cases, the dilated saccule may bulge toward adjacent structures like the footplate, exacerbating vestibular imbalance. Otolithiasis involves degeneration of otoconia in the saccule, potentially leading to balance disorders and otolith dysfunction, though (BPPV) is typically associated with utricular debris; saccular involvement may contribute to persistent postural instability. This process is often linked to age- or trauma-induced weakening of otoconia attachments in the saccule, altering its role in and sensing. Age-related degeneration progressively affects the saccule, with notable loss of type I and II cells and reduced volume starting around age 50–60, leading to diminished to linear . These histopathological changes, including otoconia demineralization and neuronal , contribute to presbyastasis, characterized by chronic unsteadiness, increased fall risk, and subtle deficits that impair daily in older adults. Otolithic structures like the saccule show greater vulnerability to aging than , correlating with overall vestibular hypofunction.

Diagnostic Techniques

Diagnostic techniques for assessing saccular function primarily focus on evaluating the otolith organ's response to linear and stimuli, aiding in the identification of vestibular disorders without invasive procedures. These methods include electrophysiological tests like vestibular evoked myogenic potentials (VEMPs), balance assessments via posturography, and imaging modalities such as magnetic resonance imaging (MRI). They provide objective measures of saccular integrity, often in conjunction with clinical history, to differentiate peripheral vestibular dysfunction from central issues. Cervical vestibular evoked myogenic potentials (cVEMP) serve as a key non-invasive test for saccular function, utilizing air-conducted sound stimuli, typically tone bursts at 500 Hz and intensities around 95-100 dB nHL, to elicit an inhibitory reflex in the sternocleidomastoid (SCM) muscle. Surface electrodes placed on the SCM record the myogenic response, characterized by a biphasic (p13-n23), which reflects saccular afferents traveling via the and inferior . Absent or reduced responses indicate saccular hypofunction, with high sensitivity for conditions affecting the otolith organ. Ocular vestibular evoked myogenic potentials (oVEMP) complement cVEMP by measuring excitatory responses in extraocular muscles, primarily the inferior oblique, to differentiate saccular from utricular contributions to vestibular function. Air- or bone-conducted stimuli evoke a small negative potential (n10) recorded suborbitally, with animal and clinical studies linking oVEMP predominantly to utricular function via the superior vestibular nerve, though combined use with cVEMP allows for otolith-specific localization of deficits. This differentiation is crucial for unilateral lesions, where interaural asymmetry in thresholds or amplitudes (e.g., >30% difference) signals pathology. Posturography evaluates saccular involvement in by quantifying postural under conditions simulating linear , using force platforms to measure center-of-pressure deviations during static or dynamic tasks on compliant surfaces. The saccule's detection of vertical linear (e.g., 0.05 m/s²) contributes to anterior-posterior , and deficits manifest as increased in sensory organization tests, particularly those isolating vestibular cues. This method provides quantitative insights into otolith-mediated postural control, with normative data showing age-related declines in sensitivity. Magnetic resonance imaging (MRI), particularly with contrast and delayed acquisition (4 hours post-intravenous injection), visualizes structural anomalies in the saccule, such as endolymphatic hydrops, where expanded endolymphatic space exceeds 50% of vestibular volume. High-resolution MRI sequences, like 3D-FLAIR, detect saccular dilation as the earliest sign in vestibular hydrops, with grading systems (e.g., grade I: mild saccular enlargement) correlating to clinical symptoms. Recent findings as of describe an "invisible saccule" (IS) on MRI, linked to loss of anatomical support, collapse, and of the , observed in patients with hearing impairment and vertigo. This confirms anatomical integrity and rules out congenital malformations or tumors affecting the saccule. Recent advancements post-2020 in VEMP testing have enhanced saccule-specific evaluation through refined air-conducted oVEMP protocols, incorporating body position manipulations and masking techniques to isolate saccular responses more precisely in non-invasive settings. These include optimized stimulus parameters (e.g., 500 Hz tone bursts) and simultaneous cVEMP/oVEMP recordings for improved diagnostic accuracy in otolith disorders, as reviewed in clinical guidelines emphasizing threshold reductions and waveform reliability.

Therapeutic Interventions

Therapeutic interventions for saccular dysfunction primarily target conditions such as with saccular hydrops, and profound vestibular loss. for saccular involvement in focuses on reducing endolymphatic hydrops through diuretics, such as hydrochlorothiazide, which decrease fluid pressure in the inner ear and thereby alleviate vertigo and associated symptoms. These agents are often combined with a low-sodium diet to enhance their effect on saccular function. For refractory cases of saccular hydrops, surgical options include endolymphatic sac , which relieves on the saccule and controls vertigo in 60-90% of patients while preserving hearing. Vestibular nerve section serves as an alternative ablative procedure for severe, unresponsive symptoms, selectively interrupting afferent signals from the affected saccule without impacting auditory pathways. Emerging therapies in the 2020s emphasize regenerative approaches, such as upregulating Atoh1 to promote regeneration in the saccule, showing promise in preclinical models for restoring vestibular function. Additionally, vestibular implants are under investigation for profound saccular loss, providing electrical stimulation to bypass damaged organs and improve in bilateral vestibulopathy.

References

  1. [1]
    The Otolith Organs: The Utricle and Sacculus - Neuroscience - NCBI
    The utricle and sacculus are otolith organs that detect head displacements. The utricle responds to horizontal movements, and the sacculus to vertical ...
  2. [2]
    Chapter 10: Vestibular System: Structure and Function
    The vestibular system monitors gravity and body orientation, using semicircular ducts and otolith organs in the inner ear to adjust body position.
  3. [3]
    Patient's Guide to the Normal Ear | Otolaryngology - Stanford Medicine
    The otolith organs (utricle and saccule) provide information on movement in a straight line and tipping (linear acceleration). These organs are located in the ...
  4. [4]
    First evolutionary insights into the human otolithic system - PMC
    Oct 2, 2024 · The human otolithic system (utricle and saccule), housed within the bony vestibule of the inner ear, establishes our sense of balance in ...
  5. [5]
    A Synchrotron and Micro-CT Study of the Human Endolymphatic ...
    May 31, 2021 · The saccule macula was placed in a pit in the medial bony wall margined posteriorly by a lip of the spherical recess. The saccular wall was ...
  6. [6]
    None
    Summary of each segment:
  7. [7]
    Vestibule Of The Ear - an overview | ScienceDirect Topics
    The saccule is about 2.6 mm in length and 1.2 mm at its widest point. Unlike the utricular macula, the saccular macula is in a vertical plane on the wall of ...
  8. [8]
    Vestibular system overview | International Pediat
    The human vestibular organ is located in the deep parts of the skull ... The utricle and the saccule on an average are 2.7mm in length and the former ...
  9. [9]
    The Anatomical and Physiological Framework for Vestibular ...
    Oct 8, 2012 · The vestibule contains two membranous sacs collectively called the otolith organs, the utricle and saccule, as well as the endolymphatic duct ...Missing: macroscopic features
  10. [10]
    Form and function of the mammalian inner ear - Ekdale - 2016
    Apr 25, 2015 · The inner ear of mammals consists of the cochlea, which is involved with the sense of hearing, and the vestibule and three semicircular canals.
  11. [11]
    Comparative Anatomy of the Bony Labyrinth (Inner Ear) of Placental ...
    The size of the labyrinth is correlated to the overall body mass of individuals, such that large bodied mammals have absolutely larger labyrinths. The ratio ...
  12. [12]
    The Formation of Otoliths in the Frog Rana esculenta. Scanning ...
    Two crystal forms of calcium carbonate were observed: calcite (utricle) and aragonite (saccule, lagena, endolymphatic sac). The first step in otolith ...
  13. [13]
    Saccule - an overview | ScienceDirect Topics
    Ion-transporting dark cells along the margins of the macula likely play a role in maintaining ionic homeostasis in the saccular epithelium. 9. 3. Neural ...
  14. [14]
    Stria vascularis and vestibular dark cells: characterisation of main ...
    The stria vascularis and vestibular dark cells are the two main structures responsible for endolymph secretion, and possess many similarities.Missing: pillar | Show results with:pillar
  15. [15]
    Neuroanatomy, Cranial Nerve 8 (Vestibulocochlear) - NCBI - NIH
    May 22, 2023 · The vestibulocochlear nerve consists of the vestibular and cochlear nerves, also known as cranial nerve eight (CN VIII). Each nerve has ...Introduction · Structure and Function · Nerves · Surgical Considerations
  16. [16]
    Vestibular Hair Cells - Neuroscience - NCBI Bookshelf - NIH
    In a given semicircular canal, the hair cells in the ampulla are all polarized in the same direction (Figure 14.2C). In the utricle and sacculus, a specialized ...
  17. [17]
    Physiology, Vestibular System - StatPearls - NCBI Bookshelf
    The utricle and the saccule are responsible for sensing linear acceleration, gravitational forces, and tilting of the head. ... acceleration that results in the ...
  18. [18]
  19. [19]
    Vestibular Heading Discrimination and Sensitivity to Linear ...
    We compared vestibular heading thresholds with corresponding measurements of sensitivity to linear motion along lateral and vertical axes of the head.
  20. [20]
    TMC1 and TMC2 are components of the mechanotransduction ...
    The data demonstrate TMC1 and TMC2 are components of hair cell transduction channels and contribute to permeation properties.
  21. [21]
  22. [22]
    Sustained and Transient Vestibular Systems: A Physiological Basis ...
    Mar 30, 2017 · Otolithic afferents with regular resting discharge respond to gravity or low-frequency linear accelerations, and we term these the static or ...
  23. [23]
    Why Should Constant Stimulation of Saccular Afferents Modify the ...
    Feb 21, 2022 · Saccular afferents travel in the inferior vestibular nerve, along with afferents from the posterior semicircular canal. Saccular afferent ...
  24. [24]
    Neuroanatomy, Vestibulo-ocular Reflex - StatPearls - NCBI Bookshelf
    Jul 25, 2023 · Otolith organs are sensitive to linear acceleration and therefore detect the position of the head relative to gravity and head translation.
  25. [25]
    Vestibular Convergence Patterns in Vestibular Nuclei Neurons of ...
    Perception and control of motion, spatial orientation, and motion-centered neuromotor behavior all depend on rapid accurate detection of the orientation and ...
  26. [26]
    Vestibular system - Scholarpedia
    Jan 24, 2008 · Most neurons in the vestibular nuclei receive convergent inputs from the otolith end organs and semicircular canals. Thus neurons not only ...
  27. [27]
    Multisensory integration in balance control - ScienceDirect.com
    Visual, somatosensory (proprioceptive), and vestibular inputs interact strongly and continuously in the control of upright balance. Experiments with visual ...Missing: saccule | Show results with:saccule
  28. [28]
    Frequency sensitivity range of the saccule to bone-conducted stimuli ...
    We report the results of an experiment to investigate whether acoustic stimulation of the saccule by bone conduction produces VEMPs in which response amplitudes ...
  29. [29]
    Sensitivity of Vestibular System to Sounds - Indian Journal of Otology
    The cochlea is an organ of hearing, the vestibule is responsible for maintaining the body's balance in linear acceleration (saccule and utricle), and angular ( ...<|separator|>
  30. [30]
    Safe Use of Acoustic Vestibular-Evoked Myogenic Potential Stimuli
    Due to frequency tuning within the stimulus pathway, 500-Hz tone bursts are described as the most effective stimulus, as they produce large amplitude responses ...
  31. [31]
    Vestibular evoked myogenic potentials - ScienceDirect.com
    The stimulation parameters that ensure a satisfactory response are a Tone Burst with a frequency of 500 Hz [3], starting at an intensity of between 90 and 100 ...2. Test Method · 2.1. Cervical Vemp (cvemp) · 2.2. Ocular Vemp (ovemp)
  32. [32]
    Vestibular evoked myogenic potentials in practice: Methods, pitfalls ...
    Feb 26, 2019 · Vestibular evoked myogenic potentials (VEMPs) are used to test the otolith organs in patients with vertigo and imbalance.
  33. [33]
    Investigation of Mechanisms in Bone Conduction Hyperacusis With ...
    The model-predicted air-bone gap for a SSCD of 1 mm2 is 30 dB at 100 Hz that decreases with frequency and become non-existent at frequencies above 1 kHz.Missing: saccule | Show results with:saccule
  34. [34]
    Diversity in Fish Auditory Systems: One of the Riddles of Sensory ...
    Low ambient noise levels may have facilitated the evolution of AHS, enabling fish to detect low-level abiotic noise and sounds from con- and heterosopecifics, ...
  35. [35]
    Structure–function relationships in fish otolith organs - ScienceDirect
    Fish otolithic organs (utricle, lagena, saccule) have a dual function, both vestibular and auditory, and are part of the inner ear.
  36. [36]
    [PDF] Vestibular Activation by Sound in Human - SAS Publishers
    Auditory sensitivity of the saccule augments bone-conducted low frequency hearing thresholds in deaf patients, which may be mediated through vestibular endings ...
  37. [37]
    Vestibular system: Anatomy, pathway and function | Kenhub
    The utricle and saccule, which contain the cells that detect the linear acceleration ... hair cells, moving the stereocilia toward the kinocilium. These ...
  38. [38]
    Vestibular Nerve - an overview | ScienceDirect Topics
    The vestibular nerve is a critical sensory nerve responsible for transmitting impulses involved in maintaining equilibrium from the inner ear to the brainstem, ...<|control11|><|separator|>
  39. [39]
    Embryology, Ear - StatPearls - NCBI Bookshelf - NIH
    Aug 8, 2023 · The ventral saccular portion gives rise to internal ear structures involved in hearing, including the cochlear ducts and saccules. The dorsal ...
  40. [40]
    Embryology of Inner Ear and Its Malformation - Ento Key
    Oct 3, 2017 · The otocyst separates from the neural crest around gestation week 4, and the endolymphatic duct develops around gestation week 5. The membranous ...
  41. [41]
    Defining developmental trajectories of prosensory cells in human ...
    Jun 29, 2023 · After hair cell differentiation, SOX2 expression quickly subsides in type I hair cells in the vestibular end organ, and in inner and outer hair ...
  42. [42]
    Expression of PAX2 Gene During Human Development - PubMed
    Abstract. The expression of human paired-box-containing PAX2 gene was examined in 7 human conceptuses 6 to 9 weeks old by in situ hybridization.
  43. [43]
    Defining developmental trajectories of prosensory cells in human ...
    During inner ear development, prosensory cells arise from a subpopulation of PAX2/PAX8-positive multipotent otic progenitors and give rise to mechanosensitive ...
  44. [44]
    Sem observations on development of human otoconia during the ...
    X-ray analysis showed that a marked increase in otoconial calcium content occurs during the period from 7 to 12 weeks gestational age. Original language ...
  45. [45]
    Mechanisms of Otoconia and Otolith Development - PubMed Central
    The utricle and saccule are the two gravity receptor organs and contain otoconia, bio-crystals of calcium carbonate (CaCO3) and proteins. Non-mammalian ...
  46. [46]
    Neurosensory Differentiation and Innervation Patterning in the ...
    Nov 15, 2016 · Our study provides first-hand insight into the fetal development of the vestibular end organs as well as their pattern of innervation by means ...
  47. [47]
  48. [48]
    Congenital Malformations of the Inner Ear - Ento Key
    Jul 15, 2019 · Histologically, incomplete partition appears to be the radiographic correlate of classical Mondini dysplasia ( Fig. 13-9 ). In numerous reported ...Complete Labyrinthine... · Incomplete Partition... · Enlargement Of The...
  49. [49]
    Evolution of vertebrate mechanosensory hair cells and inner ears
    In an apparent form of ontogenetic recapitulation, the hair cells of vertebrates develop through an ontogenetic stage, where a central kinocilium forms ...
  50. [50]
  51. [51]
  52. [52]
    Afferent Innervation Patterns of the Saccule in Pigeons
    The saccular macula is elongated through the anterior-posterior dimension. The neuroepithelium is densely populated with receptor hair cells, each having a ...
  53. [53]
  54. [54]
    First evolutionary insights into the human otolithic system - Nature
    Oct 2, 2024 · The divergence of hylobatids and hominids relates to the size of the bony structure of the saccule relative to that of the utricle (see Figs. 4c ...
  55. [55]
  56. [56]
  57. [57]
  58. [58]
  59. [59]
    Practice guideline: Cervical and ocular vestibular evoked myogenic ...
    The cVEMP test is believed to assess saccular vestibular signals carried via the vestibulospinal tract. cVEMP is performed by applying sound stimulation to 1 ...
  60. [60]
    Cervical Vestibular Evoked Myogenic Potentials in Meniere's Disease
    Introduction. The cervical vestibular evoked myogenic potential (cVEMP) is used to evaluate the function of the saccule and inferior vestibular nerve.
  61. [61]
    Cervical vestibular-evoked myogenic potentials (cVEMPs)
    This test evaluates the functionality of the saccule end organ through an inhibitory reflex on the sternocleidomastoid (SCM) muscle that inhibits the level of ...
  62. [62]
    Cervical and ocular vestibular evoked myogenic potential testing
    Vestibular evoked myogenic potential (VEMP) testing averages short latency myogenic responses evoked by sound that stimulates activation of the saccule or ...
  63. [63]
    Ocular Vestibular Evoked Myogenic Potentials: Where Are We Now?
    Different lines of anatomical, neurophysiological, and clinical evidence support the notion that oVEMPs measure predominantly contralateral utricular function, ...Utricular Origin Of Ovemps · Recording Of Ovemps · Stimuli
  64. [64]
    Assessment of diagnostic accuracy of foam posturography for ...
    The otolith organs, which are composed of the utricle and saccule, operate as multidirectional linear accelerometers in the diverse polarization of the maculae.
  65. [65]
    [PDF] Comparison of Computerized Dynamic Posturography (CDP) results ...
    The saccule detects linear acceleration in the vertical plane, while the utricle detects linear acceleration in the horizontal plane. Both the utricle and ...
  66. [66]
    Age-related changes to vestibular heave and pitch perception and ...
    Apr 19, 2022 · These results suggest that vestibular perceptual sensitivity declines with older age and that such declines are associated with poorer postural stability.
  67. [67]
    Imaging of the saccule for the diagnosis of endolymphatic hydrops in ...
    Oct 9, 2017 · Endolymphatic hydrops can be studied on magnetic resonance imaging (MRI) using images acquired 4 h after intravenous injection of Gd-chelate.
  68. [68]
    MRI in Menière's Disease | Journal of the Belgian Society of Radiology
    Nov 17, 2018 · The saccule is the smallest of both structures and is located anterior, inferior, and medial in the vestibule (Figure 2a). A grade I vestibular ...
  69. [69]
    Delayed post-contrast MRI in the assessment of Meniere's disease ...
    Apr 17, 2023 · Typically the saccule is the first vestibular endolymphatic structure to become hydropic, and represents the earliest imaging manifestation of ...
  70. [70]
    Thirty years with cervical vestibular myogenic potentials - Frontiers
    Jan 21, 2025 · This examination became better known as cervical vestibular evoked myogenic potentials (cVEMPs) and gained increasing clinical application since the nineties.
  71. [71]
    Clinical usefulness of vestibular-evoked myogenic potential testing
    Nov 18, 2024 · It has been three decades since the development of vestibular-evoked myogenic potential (VEMP) test. Now is an opportune moment to review ...
  72. [72]
    A Study on Masking Cervical Vestibular Evoked Myogenic Potentials ...
    Feb 28, 2025 · We employed a new acoustic masking method to obscure BCV VEMP, aiming to explore the feasibility of unilateral BCV VEMP testing.
  73. [73]
    Gene therapy: an emerging therapy for hair cells regeneration in the ...
    May 2, 2023 · In this review, we highlight how gene therapy can promote hair cell regeneration as a way to alleviate the hearing loss in patients and provide ...Missing: saccule 2020s
  74. [74]
    Effect of Self-treatment of Recurrent Benign Paroxysmal Positional ...
    Jan 17, 2023 · The canalith repositioning maneuver (CRM) can effectively treat BPPV. ... CRM results in immediate resolution of BPPV in about 80% of patients ...Missing: saccular otolith
  75. [75]
    Meniere's disease: Pathogenesis, treatments, and emerging ...
    Dec 1, 2023 · Meniere's disease (MD) is a severe inner ear condition known by debilitating symptoms, including spontaneous vertigo, fluctuating and progressive hearing loss.
  76. [76]
    A Systematic Review of Diuretics in the Medical Management of ...
    Mar 1, 2016 · Multiple low evidence–level studies report that oral diuretic therapy may be beneficial in the medical management of Ménière's disease.
  77. [77]
    Surgical Treatment of Meniere Disease - Medscape Reference
    Dec 26, 2018 · Endolymphatic sac surgery controls vertigo in 60-90% of patients, it has a low risk of hearing loss, and it can improve the patient's hearing ...
  78. [78]
    Endolymphatic Sac Surgery for Ménière's Disease - NIH
    The surgical options include labyrinthectomy, vestibular neurectomy, endolymphatic sac surgery and transtympanic gentamicin injections for a chemical ...
  79. [79]
    Vestibular Implantation | Current Otorhinolaryngology Reports
    May 2, 2024 · Vestibular implants are an investigational technology with the potential to provide treatment options for patients with chronic bilateral vestibulopathy.