The Ear Flashcards
what are the three parts of the outer ear (pinna)
tragus, helix, lobule
what goes through the external auditory meatus to the ear
Auriculotemporal branch of the mandibular nerve (V)
greater auricular (C2,3)
vagus nerve
what does the Auriculotemporal branch of the mandibular nerve (V) innervate in ear
sensory supply upper half of outer ear
what innervates the lower half of outer ear
greater auricular
what innervates the posterior wall and floor of the outer ear
vagus nerve
what is another name for the middle ear
tympanic cavity
what are the three ossicles of the middle ear
malleus, incus and stapes
what does the eustachian tube connect the middle ear to
nasopharynx
what are the two muscles in the middle ear
stapedius and tensor tympani
what is on the roof of the middle ear
tegmen tympani (petrous part of temporal bone)
what is the floor of the middle ear
fundus tympani (jugular wall)
what is in the fundus tympani
contains small aperture for the passage of the tympanic branch of the glossopharyngeal nerve
what is the lateral wall of the middle ear
tympanic membrane and canal for chords tympani
what is the anterior wall of the middle ear perforated by
tensor tympani muscle and auditory canal
what are the four main structures of the mastoid sinus
Aditus ad antrum: Connects epitympanum to mastoid antrum
Mastoid antrum: Large, central mastoid air cell
Körner septum: Part of petrosquamosal suture running posterolaterally through mastoid air cells
Tegmen mastoideum: Roof of mastoid air cells
what is the function of the tympanic membrane
Separates the tympanic cavity from the external meatus
sound transmission, and amplification
what supplies the tympanic membrane
the maxillary artery’s deep auricular branch, the stylomastoid branch of the occipital or the posterior auricular artery and the tympanic branch of the maxillary
what drains the tympanic membrane
superficial drain to external jugular and deep surface drain partly to transverse sinus and dural veins and partly to venous plexus of eustachian tube.
what innervates the tympanic membrane
auriculotemporal branch of mandibular nerve, auricular branch of the vagus, tympanic branch of glossopharyngeal and facial nerve.
what muscles dampen sound waves
tensor tympani and stapedius
wha innervates the tensor tympani
mandibular nerve
what innervates the stapedius
facial nerve
what can develop if mastoid air cells are infected
mastoidtis
what is the function of the mastoid air cells
protect the delicate structures of the ear, regulate ear pressure and help drain fluid from inner ear
which is the first ossicle to reciev vibrations from the tympanic membrane
malleus
what is in the tympanic plexus
Sensory branches of facial nerve
Sensory branches of glossopharyngeal nerve
Nerve of Jacobson
Greater Petrosal Nerve
Gives rise to Lesser petrosal nerve
what enters the ear through the internal acoustic meatus
facial and vestibulocochlear nerves
describe the movement of vibrations through the inner ear
As the oval window moves, waves move through the perilymph fluid inside the scala tympani and then the scala vestibuli of the cochlea
When fluid moves through these structures, the basilar membrane (located between the scala media and scala tympani) shifts respectively to the tectorial membrane
what is the receptor for sound in the inner ear
neuroepithelial cell in the organ of corti
what are the two branches of the vestibulocochlear
vestibular and cochlear
what is the function of the vestibular nerve
body balance and eye movements
what is the function of the cochlear nerve
hearing
what are the three sensory systems that contribute to balance
visual
Conscious proprioceptive system (sensory ataxia)
Vestibular system (static labyrinth)
what is a clinicl perspective in the tympanic membrane
Tympanic membrane perforation / ruptured eardrum
This can be caused by infection, trauma, or rapid changes in pressure leading to sudden otalgia, otorrhea, tinnitus, and vertigo.
what is glue ear
a condition where fluid builds up inside your middle ear and becomes thick and sticky - occurs after cold or ear infection
