Ear Flashcards
Division of the ear - anatomical and functional?
Anatomical: - outer, middle and inner Functional: in temporal bone - hearing via cochlea - balance via semicircular canals
Name the 3 constituents of the outer ear?
Auricle
EAM and canal
Tympanic membrane
Name the 4 constituents of the middle ear?
Tympanic membrane
tymapnic cavity
Ossicles
Pharyngotympanic tube (auditory)
Name the 5 constituents of the inner ear?
Cochlea Semicircular canals IAM CN VIII Oval and round window
Auricle - anatomy (5)? shape? innervation?
Helix Antihelix Tragus Antitragus Pinna Funnel shaped Auriculotemporal (ant) and vagus (post)
EAM - function?
Funnels sound to the tympanic membrane
Tympanic membrane - function? innervation (2)?
Vibrates in response to sound waves and apsses vibarations to the malleus
CN IX and auriculotemporal (V3)
Mastoid antrum - location? function? pathway for infection?
Within mastoid part of temporal bone
Communicates with middle ear via aditus
From nose/mouth via pharyngotympanic tube to middle ear -> aditus -> antrum -> mastoid air cells, cerebellum, temporal lobe -> meningitis/brain abscess
Ossicles - function? name the 3 bones?
Pass vibrations from tympanic membrane to oval window
Malleus
Incus
Stapes
Malleus - shape? attachment? tensor tympani?
Hammer
attached to the tympanic membrane then to the incus
Tensor tympani attaches into the handle
Incus - shape? attachment?
Anvil
articulates with head of malleus and head of stapes
Stapes - shape? attachment?
Stirrup
articulates with the incus and the oval window
Stapedius attaches to the neck of the stapes
Tensor tympani - action? innervation?
Tenses tympanic membrane
Mandibular branch of V
Stapedius - action? innervation?
Pull footplate of stapes laterally
Facial nerve
Combined action of tensor tympani and stapedius?
Reduce vibration passing to inner ear
Auditory tube - connection? open when? action? sensory innveration?
Nasopharynx and tympanic cavity
Tensor tympani contracts
Equalises pressure from both sides of tympanic membrane
IX
Chorda tympani - arises from? joins the? parasymph innervation to? special sensory inneravtion to?
Facial nerve
Lingual nerve
Sublingual and submandibular glands
Ant 2/3 tongue
Bony labyrinths - definition? anatomy?
A system of canals filled with perilymph
Cochlea
vestibule
Semicircular canals
Membranous labyrinths - definition? suspended in? contain?
Continuous system of ducts and sac inside the bony labyrinth
Perilymph
Endolymph
Saccule continuous with?
Cochlea
Utricle continuous with?
Semicircular ducts?
Saccule and utricle house which receptor?
Balance receptors
Maculae
Maculae respond to?
Pull of gravity and report changes of head position
Semicircular canals - number? swelling?
3 anterior, posterior and lateral
Ampulla
Ampullae - defintion? responds to? records?
Contain balance sensing area called ampullary crest
Responds to rotational movement of the head
Records endolymph movement
Bony cochlea - shape? innervation? oval window?
Snail-shell shaped
CN VIII
Oval window covered by 2dary tympanic membrane to disperse sound
Cochlear duct - definition? wave of hydraulic Pa?
Endolymph filled duct surrounded by 2 perilymph channels (scala vestibuli and scala tympani)
Travels from oval window up scale vestibuli to apex (helicotrema) and down the scala tympani
Organ of Corti - located in? innervation? stimulation?
Basilar membrane overlied by the tectorial membrane
CN VIII
Deformation of cochlear duct induced Pa wave in perilymph stimulating hair cells in Organ
