Anatomy - Ear Flashcards
name the 3 divisions of the ear
external
middle
inner
name the 2 functional divisions of the ear
hearing - auditory
balance - vestibular
the ear is located in what bone?
temporal bone
the temporal bone contains which 2 nerves?
CN VII and CN VIII
on lateral view of the temporal bone, name the 4 important features
external acoustic meatus
mastoid process
styloid process
zygomatic process
name the H shaped suture of the skull and name the 4 bones it connects
pterion
parietal
frontal
temporal
sphenoid
what does petrous mean?
rock-like
CN VII and VIII pass through what to exit the cranium?
internal acoustic meatus
CN VII:
motor to \_\_\_\_ motor to \_\_\_\_\_\_\_\_\_\_ taste to \_\_\_\_\_\_\_\_\_ _/3rd of tongue secretomotor to \_\_\_\_\_\_\_\_\_\_\_ and \_\_\_\_\_\_\_\_\_ glands sensation to \_\_\_\_\_\_\_\_\_ ear
CN VII:
motor to FACE motor to STAPEDIUS taste to ANTEROR 2/3rd of tongue secretomotor to SALIVARY and LACRIMAL glands sensation to EXTERNAL ear
name the part of the ear:
tympanic membrane to oval window
also Eustachian tube
amplifies & conducts sound waves to the internal ear
middle ear
name the part of the ear:
auricle to tympanic membrane
via external acoustic meatus
collects and conveys sound waves to tympanic membrane
external ear
name the part of the ear:
oval window to internal acoustic meatus
converts special sensory information
into fluid waves
then APs
conducts APs to brain
internal ear
where does the ear canal begin?
external acoustic meatus
the ear canal is composed of _/3rd cartilage and -/3rd bone
the ear canal is composed of 1/3rd cartilage and 2/3rd bone
the ear canal is lined with what?
skin
what glands produce earwax?
ceruminous glands
name the 2 parts to the temporal bone
squamous part and petrous part
name the 6 parts to the auricle/pinna
helix anti-helix concha tragus anti-tragus eat lobe
innervation to the auricle/pinna:
C2,3
CN VII
CN V3
CN X
lymphatic drainage of the auricle:
all eventually drain to where then where?
deep cervical lymph nodes then thoracic duct or right lymphatic duct
what direction do you pull the auricle when examining the middle ear with a otoscope? adult and child?
posteroinferiorly in child
posterosuperiorly in adult
name the thick and name the thin part of the tympanic membrane on the posteriorinferior and superior aspect of it respectively
superior - pars flaccida - thin
posteroinferorly - pars tensa - thick
name the most inwardly depressed part of the tympanic membrane
umbo
name the general sensory innervation of the internal and external surface of the tympanic membrane
internal - CN IX
external - CN V3 and X
name the sensory innervation to the middle ear cavity, Eustachian tube, nasopharynx, oropharynx, tonsils
CN XI
the eustachian tube connects the tympanic cavity to the lateral wall of the ______________
the eustachian tube connects the tympanic cavity to the lateral wall of the NASOPHARYNX
name the 3 bones of the middle ear
malleus
incus
stapes
name the 2 muscles of the middle ear
stapedius (smallest skeletal muscle in the body)
tensor tympani
the middle ear is supplied by nerve branches from what 2 nerves?
facial nerve and glossopharyngeal
what type of joints are between the bones of the middle ear?
synovial joints
the base of the stapes fits into what?
the oval window - connection of middle to inner ear
state the innervation of the stapedius muscle
CN VII
mastoiditis is due to spread of infection from the ______ ear cavity
mastoiditis is due to spread of infection from the MIDDLE ear cavity
the aditus is the doorway into the ________ antrum from the epitympanic recess
the aditus is the doorway into the MASTOID antrum from the epitympanic recess
the auditory and pharyngotympanic tube are other words for what?
eustachian tube
what does the Eustachian tube connect?
anterior wall of the middle ear cavity to nasopharynx
name the common sensory nerve supply of the eustachian tube
CN IX
name the sensory innervation of the naso and oropharynx
CN IX
name the sensory innervation of the laryngopharynx
CN X
where is the opening of the Eustachian tube?
nasopharynx
where does CN VII connect to the CNS?
brainstem at the pontomedullary junction
where does CN VII leave the skull?
stylomastoid foramen
where does CN VII travel through before emerging out the stylomastoid foramen?
internal acoustic meatus
what connects the internal acoustic meatus to the stylomastoid foramen in which CN VII travels through?
facial canal of the petrous temporal bone
chordates tympani is a branch of what nerve?
CN VII
what nerve supplies taste to anterior 2/3rd of tongue and parasympathetic supply to the submandibular & sublingual salivary glands (salivation)?
chorda tympani
what muscle reduces stapes movement to protect the internal ear from excessive noise?
stapedius
what nerve does chorda tympani connect with to supply the salivary glands?
lingual nerve branch of CN V3
what is the border called surrounding the lips?
vermillion border
name the 4 major facial muscles
frontalis
orbicularis oculi
elevators of lip
orbicularis oris
what do you ask the patient to do to test CN VII suppling the facial muscles?
frown
close eyes tightly
smile
maintain puffed out cheeks
CN VIII is in two parts for hearing and balance - name them.
hearing - cochlear nerve
balance - vestibular nerve
in what bone does the otic capsule sit?
temporal bone
what does the otic capsule contain?
bony labyrinth - fluid (perilymph) filled, spaces inside otic capsule
what is suspended within the perilymph of the bony labyrinth?
- membranous labyrinth
- communicating sacs and ducts
- contains endolymph fluid
how many semicircular canals of the labyrinth are there?
3
name the 3 semicircular canals of the labyrinth
superior
lateral
posterior
name the 2 windows of the labyrinth
oval window
round window
name the 3 parts to the cochlea
1st turn
2nd turn
cupula (apex of spiral)
(2.5 turns altogether)
the __________ labyrinth sits within the ____ labyrinth
the MEMBRANOUS labyrinth sits within the BONY labyrinth
name the long balloon-like structure within the cochlea filled with endolymph
cochlear duct
APs conducted in the cochlear duct to the brainstem is via which nerve?
cochlear nerve
name the inter-linked balloon-like structures within the semicircular canals filled with endolymph
semicircular ducts
APs conducted in the semicircular duct to the brainstem is via which nerve?
vestibular nerve
name the dilatations at the end of the semicircular canals
ampullae
clusters of hair cells are in regions called what?
maculae
semicircular ducts detect ________ movement change
semicircular ducts detect ANGULAR movement change
what 2 things detect linear movement change?
urticle and saccule
what detects linear horizontal movement change?
urticle
what detects linear vertical movement change?
saccule
sound transmission:
- sound waves make ________ membrane vibrate
- vibrations transmitted through ________
- base of stapes vibrates in ____ window
- vibration of stapes creates pressure waves in _________
- hair cells in the cochlea are ______, APs stimulated and conveyed to brain by ________ nerve
- pressure waves descend and become __________ again
- pressure waves are dampened at the _____ window
sound transmission:
- sound waves make TYMPANIC membrane vibrate
- vibrations transmitted through OSSICLES
- base of stapes vibrates in OVAL window
- vibration of stapes creates pressure waves in PERILYMPH
- hair cells in the cochlea are MOVED, APs stimulated and conveyed to brain by COCHLEAR nerve
- pressure waves descend and become VIBRATIONS again
- pressure waves are dampened at the ROUND window
receptor cells in what detect auditory stimuli?
organ of corti
the organ of corti is located where?
basilar membrane of cochlear duct
the cochlear duct is suspended by spiral _________ and divides cochlear canal into ___ parts - name them
the cochlear duct is suspended by spiral LIGAMENTS and divides cochlear canal into TWO parts:
SCALA VESTIBULI
SCALA TYMPANI
where does CN VIII connect with the CNS?
brainstem at the pontomedullary junction