Ear Flashcards
Components of external ear
External auditory acoustic meatus
Auricle
External auditory meatus
Conducts sound to tympanic membrane
Components of the auricle (pinna)
Helix Anti helix Concha Lobule (earlobe) Tragus
How does sound travel?
Sound (vibrations) travel through EAM to tympanic membrane, TM moves, and vibrations are transmitted to the auditory ossicles
What are the three bones of the auditory ossicles?
Malleus
Incus
Stapes
What is the middle ear connected to?
Middle ear is connected to the nasopharynx via pharyngotympanic tube
The pharyngotympanic tube is also known as
Auditory tube aka Eustachian tube
The middle ear is protected by which two muscles?
Tensor tympani and stapedius
Tensor tympani
Pulls malleus medially and tenses tympanic membrane which reduces the amplitude of oscillations
Stapedius
Pulls stapes posteriorly away from the oval window and reduces oscillatory range
Describe the pharyngotympanic tube
It connects the tympanic cavity to nasopharynx
There is a bony part and a cartilaginous part
It is lined by a mucous membrane
Function of the pharyngotympanic tube
Equalize pressure in the middle ear with atmospheric pressure
Are the walls of the tube normally open or closed?
The walls are normally closed and must be actively opened by the muscles of the soft palate
What are the muscles of the soft palate?
Levator veli palatini
Tensor veli palatini
Otitis media
Middle ear infection
Common in infants and juveniles bc short and less angled PT tube