Flashcards in this deck (184)

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• External ear components include the auricle, the external auditory meatus (EAM), and cerumen.
  ear external
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• The tympanic membrane is a three-layered barrier.
  tympanic membrane
• Middle ear key components include the ossicles and the Eustachian tube mucosa.
  middle ossicles eustachian
• The inner ear consists of a bony labyrinth and a membranous labyrinth, and contains two fluid compartments: perilymph and endolymph.
  inner labyrinth fluids
• Sensory hair cells have stereocilia and are found in the Organ of Corti, the macula, and the crista.
  haircells sensory organofcorti
• Linking structure to function: the histologic organization of the external, middle, and inner ear connects structure to hearing and balance function.
  histology function
• External ear components include: - auricle - external acoustic meatus (EAM) - cerumen
  external ear histology
• The tympanic membrane functions as a three-layered barrier.
  tympanic membrane ear
• The middle ear contains ossicles and an auditory tube mucosa that supports mucociliary clearance; dysfunction can relate to otitis media.
  middle ear otitis
• The inner ear consists of a bony labyrinth and a membranous labyrinth, with distinct fluid compartments of perilymph and endolymph.
  inner labyrinth ear
• Sensory hair cells of the ear share the presence of stereocilia; regional specializations include: - Organ of Corti - macula - crista ampullaris
  haircells sensory ear
• Altered histologic structure in different regions of the ear can lead to selected clinical consequences affecting hearing and balance.
  clinical pathology ear
• External ear components include: - auricle (pinna) - external auditory meatus (EAM) - cerumen (earwax)
  ear external anatomy
• Middle ear key elements: - ossicles (malleus, incus, stapes) - Eustachian tube mucosa
  middle ear ossicles
• Inner ear structural division: - bony labyrinth - membranous labyrinth
  inner ear labyrinth
• The fluid compartments of the inner ear are endolymph and perilymph.
  inner ear fluids
• Hair cell specializations and sensory organs: - stereocilia - Organ of Corti - macula - crista
  haircells sensory cochlea
• The three auditory ossicles of the middle ear are:

  • Malleus
  • Incus
  • Stapes
  anatomy ossicles ear
• Structures labelled as parts of the inner ear include:

  • Cochlea
  • Vestibule
  • Bony labyrinth
  anatomy innerear
• The external ear structures listed include:

  • Auricle
  • External acoustic meatus
  anatomy externalear
• Two membrane openings between middle and inner ear are the Oval window and the Round window.
  anatomy middleear innerear
• The auditory (Eustachian) tube connects the Tympanic cavity to the Nasopharynx.
  anatomy auditorytube middleear
• Branches of the vestibulocochlear nerve (CN VIII) shown are the Vestibular branch and the Cochlear branch.
  neuroanatomy cnviii ear
• The main visible components of the external ear include: - auricle - external auditory meatus (EAM) - cerumen
  ear external
• The tympanic membrane functions as a three-layered barrier between the external and middle ear.
  tympanic membrane
• The abbreviation for external auditory meatus is EAM.
  eam abbreviation
• Cerumen is a component of the external ear commonly known as earwax.
  cerumen ear
• The external ear is composed of: - auricle - external acoustic meatus
  anatomy ear
• The auricle is made of elastic cartilage to provide shape and support.
  histology ear
• The external acoustic meatus ends at the tympanic membrane.
  anatomy ear
• The auricle is composed of elastic cartilage that provides shape and support.
  ear histology auricle
• Elastic cartilage micrograph features include: - chondrocytes within lacunae - dense matrix of elastic fibers

  
  histology cartilage micrograph
• The external acoustic meatus is lined by keratinized stratified squamous epithelium.
  ear histology external
• The external acoustic meatus contains hair follicles and two gland types: sebaceous and ceruminous glands.
  ear glands histology
• The main visible external ear structures include the auricle, the external acoustic meatus, and the tympanic membrane.
  ear anatomy external
• Ceruminous glands in the external acoustic meatus contribute to cerumen (earwax) alongside sebaceous gland lipid secretions.
  ear cerumen histology
• Ceruminous glands in the external auditory meatus (EAM) are modified apocrine glands.
  ear histology ceruminous
• Features visible in the micrograph of ceruminous glands include: - secretory cells - lumina - located within connective tissue
  ear histology micrograph
• Ceruminous glands are located in the external auditory meatus (EAM).
  ear anatomy ceruminous
• The tympanic membrane is a thin membrane separating the external acoustic meatus from the middle ear cavity.
  ear histology tympanic_membrane
• The tympanic membrane has three layers: - external keratinized stratified squamous epithelium - middle dense fibrous connective tissue - internal simple cuboidal mucosal epithelium
  ear histology layers
• The external surface of the tympanic membrane is keratinized stratified squamous epithelium. The internal surface is simple cuboidal mucosal epithelium.

  
  ear histology epithelium
• Components of the external ear important for sound collection include: - auricle (pinna) - external acoustic meatus (EAM) - cerumen production
  ear external
• The tympanic membrane is a three-layered barrier consisting of: - outer epithelium continuous with EAM - middle fibrous layer - inner mucosal layer continuous with middle ear
  tympanic membrane
• Key structural elements of the middle ear include the ossicles and the mucosa of the auditory (Eustachian) tube.
  middle ossicles auditorytube
• The inner ear is organized into two main labyrinths: the bony labyrinth and the membranous labyrinth; they contain perilymph and endolymph respectively.
  inner labyrinth
• Sensory hair cells feature stereocilia and are organized into sensory organs such as the Organ of Corti, the macula, and the crista.
  haircells sensory
• The auditory (Eustachian) tube mucosa is part of the middle ear and helps ventilate and equalize pressure between the middle ear and nasopharynx.
  auditorytube function
• The middle ear (tympanic cavity) is an air-filled space that transmits and amplifies sound vibrations.
  ear anatomy
• The three auditory ossicles of the middle ear are: - malleus - incus - stapes
  ossicles anatomy
• Structures in the tympanic cavity include the oval window, the round window, the stapedius muscle, and the tensor tympani (cut).
  middleear structures
• The tympanic cavity is surrounded by the temporal bone (petrous part).
  temporal bone
• The auditory tube connects the tympanic cavity to the nasopharynx.
  eustachian anatomy
• The auditory (Eustachian) tube lining contains the following cell types and structures: - Basal cells - Ciliated columnar cells - Cilia - Goblet cells
  ear histology
• Ciliated columnar cells in the auditory tube are associated with cilia.
  ear histology
• The bony labyrinth includes the semicircular canals and the cochlea.
  ear innerear labyrinth
• The membranous labyrinth includes the semicircular ducts and the cochlear duct.
  ear innerear labyrinth
• The vestibular complex consists of the macula (saccule, utricle) and the semicircular ducts.
  vestibular balance innerear
• The macula is located in the saccule and the utricle.
  macula vestibular innerear
• The cochlear branch of CN VIII connects to the cochlea (hearing) and the cochlear duct.
  cochlea cnviii hearing
• The bony labyrinth of the inner ear consists of rigid channels within the temporal bone.
  anatomy inner_ear labyrinth
• The membranous labyrinth is composed of epithelium-lined, fluid-filled sacs and ducts located within the bony labyrinth.
  anatomy inner_ear labyrinth
• • Perilymph surrounds the membranous labyrinth.
  • Endolymph, which is potassium-rich, fills the membranous labyrinth.
  physiology inner_ear fluids
• Cross-section of the cochlea shows these labeled structures: - Organ of Corti (OC) - spiral ganglion (SG) - scala vestibuli (SV) - scala tympani (ST)

  
  ear cochlea histology anatomy
• The abbreviation SG in cochlear histology stands for spiral ganglion.
  ear abbreviations cochlea
• The abbreviation SV in cochlear histology stands for scala vestibuli.
  ear abbreviations cochlea
• The abbreviation ST in cochlear histology stands for scala tympani.
  ear abbreviations cochlea
• The abbreviation CD in the cochlear cross-section stands for cochlear duct.
  ear abbreviations cochlea
• The semicircular ducts are part of the membranous labyrinth.
  innerear labyrinth
• The fluid that fills the membranous semicircular duct is endolymph, while perilymph surrounds it within the bony semicircular canal.
  endolymph perilymph
• Each semicircular duct expands into an ampulla that contains the crista ampullaris.
  ampulla crista
• The inner ear contains distinct compartments: the bony labyrinth and the membranous labyrinth.
  bony membranous
• The vestibular structures shown include the utricle and the saccule in the vestibule.
  utricle saccule
• Hair cells bear apical sensory projections called stereocilia.
  ear haircells stereocilia
• Locations of sensory hair cells in the inner ear include: - Organ of Corti - macula - crista
  ear haircells anatomy
• In the context of hearing and balance, the Organ of Corti is linked to hearing.
  hearing organ_of_corti ear
• In the context of hearing and balance, the macula and crista are linked to balance.
  vestibular ear balance
• The inner ear includes a bony labyrinth and a membranous labyrinth, and contains two fluid types: endolymph and perilymph.
  inner_ear labyrinth fluids
• Hair cells are specialized epithelial mechanoreceptors.
  ear histology haircells
• Apical stereocilia are actin-based projections anchored into the actin-rich cuticular plate.
  ear histology stereocilia
• Supporting cells provide structural support within the sensory epithelium.
  ear histology supportingcells
• At their basal surface, hair cells form synaptic contacts with associated nerve fibers.
  ear histology synapse
• Regional modifications adapt the common hair cell plan for hearing and balance.

  
  ear histology function
• Regional specializations of hair cells include: - Organ of Corti - Macula - Crista Ampullaris
  anatomy ear haircells
• The Organ of Corti is the auditory sensory epithelium of the cochlea.
  ear histology auditory
• Major structural components of the Organ of Corti include: - stereocilia - supporting cells - inner hair cell - outer hair cell - basilar membrane - tectorial membrane
  organofcorti structures cochlea
• The Organ of Corti contains both inner hair cells and outer hair cells.
  haircells cochlea histology
• Stereocilia are listed as a component of the Organ of Corti and are associated with hair cells.
  stereocilia haircells auditory
• Structures shown in Organ of Corti images include the scala tympani and cochlear nerve fibers.
  cochlea nerves scala
• The macula of the vestibular system detects linear acceleration and head position.
  vestibular macula
• The vestibular complex includes: - semicircular ducts - vestibule - utricle - saccule
  vestibular anatomy
• A vestibular hair cell contains sensory projections called stereocilia and a single kinocilium.
  haircell sensory
• The crista ampullaris is specialized for angular acceleration/rotational movement.
  vestibular crista function
• The crista ampullaris is located in the ampulla of the semicircular ducts.

  
  vestibular location innerear
• The crista ampullaris contains hair cells (stereocilia + kinocilium) and supporting cells.
  histology haircells crista
• The stereocilia of the hair cells project into a gelatinous structure called the cupula.

  
  cupula haircells vestibular
• Organ of Corti histology: - hair cells and supporting cells on the basilar membrane beneath the tectorial membrane Main role: - auditory sensory epithelium; damage causes sensorineural hearing loss
  ear hearing organ_of_corti
• Macula histology: - hair cells with kinocilium and supporting cells beneath the otolithic membrane Main role: - detects linear acceleration and head position; displaced otoconia can contribute to BPPV
  ear balance macula bppv
• Crista ampullaris histology: - hair cells with kinocilium and supporting cells beneath the cupula Main role: - detects angular acceleration/rotational movement; abnormal cupular stimulation contributes to vertigo
  ear balance crista_ampullaris vertigo
• The main components of the external ear include the auricle, the external acoustic meatus (EAM), and cerumen.
  ear external
• Key structures of the middle ear include the ossicles and the Eustachian tube mucosa.
  middle ossicles
• The inner ear consists of a bony labyrinth and a membranous labyrinth, containing perilymph and endolymph respectively.
  inner labyrinth
• Sensory hair cells have apical stereocilia and are organized in the Organ of Corti, the macula and the crista.
  haircells sensory
• The Organ of Corti is associated with hearing while the macula and crista are associated with balance.
  function hearing
• Children are more prone to otitis media because their auditory tube is shorter and more horizontal than in adults.
  otitis_media auditory_tube pediatrics
• The normal function of the auditory (Eustachian) tube is to equalize pressure and drain mucus from the middle ear.
  auditory_tube middle_ear physiology
• Sensorineural hearing loss from damage to the auditory sensory epithelium of the inner ear most directly affects the Organ of Corti.
  otology hearing
• The inner ear consists of two main labyrinths: - bony labyrinth - membranous labyrinth
  anatomy innerear
• The fluids associated with the inner ear are endolymph and perilymph.
  physiology innerear
• Hair-cell sensory epithelia in the inner ear include: - Organ of Corti - macula - crista ampullaris
  neuroscience haircells
• The middle ear contains the auditory ossicles and the mucosa of the Eustachian (auditory) tube.
  anatomy middleear
• The external ear components listed include: - auricle - external acoustic meatus (EAM) - cerumen
  anatomy externalear
• The tympanic membrane is described as a three-layered barrier.
  anatomy tympanicmembrane
• The auricle is composed of elastic cartilage covered by skin, providing flexible support.
  anatomy histology ear
• The external acoustic meatus has keratinized stratified squamous epithelium with hair follicles, sebaceous glands, and ceruminous glands; the cerumen produced traps debris and impaction can cause conductive hearing loss.
  anatomy histology cerumen
• The tympanic membrane consists of three layers: external squamous epithelium, middle fibrous layer, and internal simple cuboidal/low columnar mucosa; perforation disrupts sound conduction.
  anatomy histology tympanicmembrane
• The auditory (Eustachian) tube is lined by ciliated pseudostratified columnar epithelium with goblet cells; impaired clearance of the tube predisposes to otitis media.
  anatomy histology eustachian
• The middle ear cavity is lined by simple cuboidal to low columnar mucosa; inflammation or fluid in the cavity can impair ossicle conduction.
  anatomy histology middleear
• The scala media (cochlear duct) is the endolymph-filled cochlear duct located between the vestibular and basilar membranes.
  innerear histology
• The organ of Corti lies on the basilar membrane beneath the tectorial membrane and contains inner and outer hair cells with supporting cells.
  organofcorti hearing
• Damage to the organ of Corti causes sensorineural hearing loss.
  organofcorti clinical
• The stria vascularis is a specialized vascularized epithelium of the cochlear duct lateral wall that produces and maintains endolymph.
  striavascularis physiology
• The macula, found in the utricle and saccule, consists of hair cells and supporting cells beneath an otolithic membrane and detects linear acceleration / head position.
  macula vestibular
• The crista ampullaris in a semicircular duct ampulla contains hair cells/supporting cells beneath a cupula and detects angular acceleration.
  crista vestibular
• The spiral ganglion contains the bipolar sensory neuron cell bodies of the cochlear division of CN VIII and carries auditory information centrally.
  spiralganglion auditory
• The vestibular (Scarpa's) ganglion contains the bipolar sensory neuron cell bodies of the vestibular division of CN VIII and carries vestibular information centrally.
  scarpa vestibular
• The ear is divided into three regions: - External Ear - Middle Ear (Tympanic Cavity) - Inner Ear
  ear anatomy
• The primary function of the external ear is to collect sound waves and channel them inward; key external structures include the auricle and external acoustic meatus (EAM).
  external hearing
• The middle ear is an air-filled space that transmits and amplifies sound vibrations via the ossicles: malleus, incus, and stapes.
  middle ossicles
• The inner ear is a fluid-filled complex within the temporal bone containing sensory organs for hearing (cochlea) and balance (vestibular system).
  inner cochlea vestibular
• The auricle (pinna) is composed of a core of elastic cartilage covered by thin skin.
  ear auricle histology
• The external acoustic meatus is a canal leading to the tympanic membrane and is lined by stratified squamous epithelium.
  ear eam epithelium
• The skin lining the external acoustic meatus contains: - hair follicles - sebaceous glands - ceruminous (modified apocrine) glands
  ear glands histology
• Cerumen is produced from sebaceous lipid + ceruminous secretion and functions to trap debris and provide antimicrobial activity.
  cerumen function eam
• Histologic image: Auricular tissue often shows elastic cartilage with chondrocytes in lacunae. The core tissue type is elastic cartilage.
  histology cartilage auricle
• The tympanic membrane is a thin, taut membrane that separates the external ear from the middle ear.
  anatomy histology tympanicmembrane ear
• The external surface of the tympanic membrane is lined by stratified squamous keratinized epithelium.
  epithelium ear histology
• The internal (middle-ear) surface of the tympanic membrane is lined by low cuboidal epithelium.
  histology epithelium ear
• The core of the tympanic membrane is composed of collagen fibers disposed in two layers.

  Illustration:
  histology collagen ear
• The auditory (Eustachian) tube connects the tympanic cavity to the nasopharynx.
  ear middleear anatomy
• The auditory tube is lined with ciliated pseudostratified columnar epithelium with goblet cells (respiratory epithelium).
  ear histology epithelium
• Histologic elements visible in the auditory tube lining include: - ciliated columnar cells - basal cells - goblet cells - cilia

  
  ear histology micrograph
• Pathogenesis sequence of otitis media: viral or bacterial infection → inflammation of the nasopharynx and Eustachian tube → Eustachian tube dysfunction and negative middle ear pressure → middle ear inflammation.
  otitis pathogenesis
• Primary causes of impaired mucociliary clearance that increase risk for otitis media include: - Primary ciliary dyskinesia (PCD) - Kartagener syndrome (PCD with situs inversus)
  etiology mucociliary
• Secondary (acquired) causes of impaired mucociliary clearance that increase risk for otitis media include: - Cigarette smoke exposure - Recurrent infections - Cystic fibrosis
  riskfactors mucociliary
• Eustachian tube dysfunction in the pathogenesis of otitis media leads to negative middle ear pressure which contributes to middle ear inflammation.
  eustachian mechanism
• The inner ear's hearing organ is the cochlea, described as one coiled tube for hearing.
  ear innerear hearing
• The inner ear structures for balance consist of three loops (semicircular canals) and two sacs (vestibular sacs).
  ear innerear balance
• The diagram shows the bony labyrinth (blue) and the membranous labyrinth (orange), which include the semicircular canals, vestibule, and cochlea.
  ear labyrinth anatomy
• The Organ of Corti is the sensory organ for hearing, located on the basilar membrane within the scala media.
  ear histology auditory
• The Organ of Corti contains the sensory hair cells responsible for detecting sound-induced vibrations.
  haircells sensory auditory
• The tectorial membrane is a gelatinous layer that extends over the hair cells and their stereocilia.
  tectorial membrane auditory
• Signals from the Organ of Corti are transmitted to the spiral ganglia of the cochlear branch of cranial nerve VIII (CN VIII).
  neuro cochlea cnviii
• Macula (utricle & saccule) detects linear acceleration and head position.
  vestibular macula
• In the macula, the otolithic membrane overlies the hair cells.
  macula otolith
• Crista ampullaris (in the semicircular canals) detects angular acceleration / rotational movement.
  vestibular crista
• On the crista ampullaris, the cupula overlies the hair cells.
  crista cupula
• The auricle is composed of elastic cartilage covered by skin.
  anatomy ear
• The external acoustic meatus has keratinized stratified squamous epithelium with hair follicles, sebaceous glands, and ceruminous glands.

  Clinically, cerumen traps debris; impaction can cause conductive hearing loss.
  histology ear
• The tympanic membrane consists of: - external squamous epithelium - middle fibrous layer - internal simple cuboidal/low columnar mucosa

  Perforation disrupts sound conduction.
  tympanic ear
• The auditory (Eustachian) tube is lined by ciliated pseudostratified columnar epithelium with goblet cells.

  Impaired clearance predisposes to otitis media.
  eustachian ear
• The middle ear cavity is lined by simple cuboidal to low columnar mucosa.

  Inflammation or fluid in the middle ear can impair ossicle conduction.
  middleear histology
• The scala media (cochlear duct) is the endolymph-filled cochlear duct located between the vestibular and basilar membranes.
  innerear cochlea
• The scala media houses the organ of Corti and maintains a specialized K+ rich ionic environment necessary for hair cell function.
  cochlea ionhomeostasis
• The organ of Corti contains: - inner hair cells - outer hair cells - supporting cells and lies on the basilar membrane beneath the tectorial membrane.
  organofcorti hearing
• A macula consists of hair cells and supporting cells beneath the otolithic membrane in the utricle and saccule and detects linear acceleration/head position.
  vestibular macula
• A crista ampullaris contains hair cells/supporting cells beneath the cupula within an ampulla of a semicircular duct and detects angular acceleration/rotational movements.
  vestibular crista
• The spiral ganglion contains bipolar sensory neuron cell bodies of the cochlear division of cranial nerve VIII and carries auditory information centrally.
  spiralganglion auditory
• The vestibular (Scarpa's) ganglion contains bipolar sensory neuron cell bodies of the vestibular division of cranial nerve VIII and carries vestibular information centrally.
  vestibularganglion vestibular
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