External and middle ear Flashcards
most of the ear is found in what bone
petrous part of the temporal bone
what forms the boundary between the external and middle ear
tympanic membrane
what is the external ear (outer)
auricle, external auditory meatus, external surface of the tympanic membrane
what is the middle ear
internal surface of the tympanic membrane, tympanic cavity, ossicles, pharyngotympanic tube
what is the internal ear
auditory apparatus, vestibular apparatus, internal auditory meatus, vestibulocochlear nerve (CN VIII), oval window, round window
what vessel and nerve are anterior to the external ear
superficial temporal vessels and auriculotemporal nerve
the middle ear is related to what artery
ICA
the internal ear is surrounded by bone between which 2 cranial fossae
between middle and posterior cranial fossae
what brain lobes sit superior to the internal structures of the ear
temporal lobes of the brain
the internal acoustic meatus carries what 2 nerves
facial and vestibulocochlear
what is the function of the auricle
catch sound waves and funnel them towards the EAM
some people can wiggle their ears - what nerve innervates the muscles that control this
facial nerve
what are the 2 parts of the concha of the ear
cymba - superior, infront of anti-helix
cavity - behind tragus, inferior
what is the ear made of
elastic cartilage
where does lymph from the auricle drain
parotid and cervical lymph nodes
the auricle is supplied by branches of what blood vessel
external carotid artery
what branches of the ECA supply the auricle
posterior and anterior auricular and perforating branches
- blood drains to corresponding veins and into the external and internal jugular veins
what supplies innervation to the face anterior to the auricle
auriculotemporal nerve from CN V3
what supplies innervation to the cavity of the concha of the auricle
CN IX and CN X
what supplies innervation to the border of the auricle (lobe, helix) and skin of head behind the auricle
lesser occipital and great auricular nerves (cervical plexus)
what supplies innervation to the inner parts of the auricle (not the concha, bits around that) and the skin on posterior aspect of auricle
CN VII
where does the external auditory meatus run from
opening in the auricle into the petrous temporal bone to end at the tympanic membrane
the lateral 1/3 of the EAM is made of what
elastic cartilage, hair follicles, sweat and sebaceous glands
what are the medial 2/3 of the EAM made of
bone lined with stratified squamous epithelium
blood supply to the EAM is from
ECA - auricular
what supplies innervation to the EAM
mainly auriculo-temporal from CN V3 but also auricular branches from CN VII and CN X
what 3 cranial nerves supply innervation to the EAM
CN V3
CN VII
CN X
what ossicle attaches to the tympanic membrane
malleus
how is sound transmitted from a wave to a physical movement
sound waves move the tympanic membrane which moves the malleus in the middle ear
what is the lining of the outer tympanic membrane
stratified squamous epithelium
what is the inner lining of the tympanic membrane
mucous membrane
what nerve runs along the medial surface of the tympanic membrane
chorda tympani
what nerve supplies innervation to the lateral surface of the tympanic membrane
auriculotemporal nerve CN V3 and auricular branch of vagus
what nerve supplies innervation to the medial surface of the middle ear
tympanic branches of glossopharyngeal CN IX
the medial surface of the tympanic membrane bulges into a space inside the petrous temporal bone called what
tympanic cavity
the tympanic cavity houses what
ossicles
the ossicles link the tympanic membrane to what
oval window of the inner ear
what ossicle sits on the tympanic membrane
handle of the malleus
the malleus articulates with what bone
incus bone
the incus bone articulates with what bone
stapes
what are the ossicles in order
malleus, incus, stapes
what joints lie between the ossicles
plane synovial
what sits on the oval window
footplate/base of the stapes
what are the other names of the ossicles
lateral to medial - hammer, anvil and stirrup
what artery, vein and nerve come in close association with the middle ear
internal carotid artery
internal jugular vein
facial nerve
what does the aditus of the middle ear communicates with what
mastoid air cells
what is the function of tensor tympani
tense tympanic membrane
what is the innervation of tensor tympani
CN V3
what are the origin and insertion of tensor tympani
wall of auditory tube to handle of malleus
what is the action of stapedius
pull footplate of stapes laterally
what is the innervation of stapedius
facial nerve CN VII
what is the origin and insertion of stapedius
pyramid of middle ear and neck of stapes
what is the combined action of the stapedius and tensor tympani
reduce vibration passing to delicate inner ear
what is the sensory nerve supply to the tympanic cavity including medial surface of the tympanic membrane
CN IX
what is the blood supply to the middle ear
tympanic branches of posterior auricular, ascending pharyngeal and maxillary arteries
- also caroticotympanic from internal carotid
what is the pyramid of the middle ear
small bulge of bone
the facial nerve enters the temporal bone via
the IAM
the facial nerve enters the temporal bone via the IAM, travels through the petrous temporal bone unit it exits the skull via
stylomastoid foramen
after exiting the skull via the stylomastoid foramen, the facial nerve enters what
parotid gland
as the facial nerve passes through the temporal bone, it gives off several branches e.g. the greater petrosal nerve which passes to form what
to form the nerve of the pterygoid canal
the greater petrosal nerve which passes to form the nerve of the pterygoid canal along with what
with the deep petrosal nerve from the carotid plexus
the nerve of the pterygoid canal supplies what
parasympathetic secretomotor fibres to the lacrimal gland and small glands of the nose and palate
what are 2 more branches, as well as the greater petrosal nerve, from the facial nerve
nerve to stapedius
chorda tympani
what nerve branches from the facial nerve to cross the medial surface of the tympanic membrane and handle of malleus
chorda tympani
the chorda tympani branches from the facial nerve to cross where
cross the medial surface of the tympanic membrane and handle of malleus
the chorda tympani leaves the tympanic cavity via what
petrotympanic fissure
what nerve passes through the petrotympanic fissure
chorda tympani
the chorda tympani joins what
lingual nerve from CN V3
what does the chorda tympani supply
parasympathetic secretomotor to the sublingual and submandibular salivary glands and special taste to the anterior 2/3 of the tongue
what supplies special taste to the anterior 2/3 of the tongue
chorda tympani via lingual nerve
where does chorda tympani join the lingual nerve
infratemporal fossa
what does the auditory tube connect
nasopharynx with the tympanic cavity
describe the lateral auditory tube
bony canal lined with mucosa
describe the medial auditory tube
cartilaginous and membranous
the auditory tube is normally closed, how does it open
tensor veli palatini contracts the lumen opens
in what scenarios might tensor veli palatini contract
swallow
yawn
what is the function of the auditory tube
equalises pressure on both sides of the tympanic membrane
sensory innervation to the auditory tube
sensory via CN IX
where does the auditory tube pass from specifically
lateral wall of the nasopharynx to open into middle ear
what does the cartilage in the medial auditory tube allow attachment for
salpingopharyngeus
tensor and levator veli palatini
what happens if the pressure on each side of the tympanic membrane is unequal
tympanic membrane cant vibrate freely, so an accurate transmission of sound cannot be passed into the inner ear
the middle ear is supplied by what
branches of both the external and internal carotid arteries
the anterior tympanic artery is a branch of what
1st part of maxillary artery
the middle ear receives contributions from what arteries
- ascending pharyngeal
- middle meningeal
- posterior auricular
- artery of pterygoid canal
- caroticotympanic branch
the ascending pharyngeal artery gives what branch to the middle ear
inferior tympanic
the middle meningeal artery gives what branch to the middle ear
superior tympanic
the posterior auricular artery gives what branch to the middle ear
stylomastoid
posterior tympanic
caroticotympanic branch is a branch of what
ICA