Midterm Flashcards
What is the outer ear composed of?
Pinna
Ear Canal
Ear Drum
What is the outer ear responsible for?
Gathering sounds from the environment and funneling them down into the ear canal
Another word for Pinna
The Auricle
What is the pinna made of?
Made entirely of cartilage
The concha
Aids in localization of sounds that come from in front, behind, below and above the head
Anatomy of the pinna
Makes it more efficient at delivering high-frequency sounds than low-frequency sounds
The EAC (External Auditory Canal)
also known as external auditory meatus
elliptical shape tubed that begins at the concha and extends down to the tympanic membrane
What is the Tympanic Membrane also known as?
The eardrum
What is the greatest surface area of the Tympanic Membrane called?
Pars Tensa
Pars Flaccida
Also knowsn as shrapnells membrane is looser and contains only the epidermal and mucous membrane layers
What is the tympanic membrane held in place by?
Annulus
Umbo
the point where the bottom end of the manubrium forms the center of the eardrum
What does a healthy normal eardrum look like?
cone shaped and will produce a visible phenomenon or light reflex (cone of light)
Cone of light
anterior inferior quadrant
3 layers of the tympanic membrane
Ectoderm: cutaneous, continuous of the external auditory canal
Endoderm: mucous, continuous with the tympanic cavity
Mesoderm: fibrous, radial fibers, concentric fibers
Disorders of the Auricle
Microtia: congenital deformity where the pinna is underdeveloped
Antonia: congenital in nature , pinna is entirely absent
Dysfunctions of the External Auditory Canal
Stenosis
Collapsing ear canals
Hematoma
Cerumen Impaction
Foreign Bodies
Atresia
Absence of the external auditory canal
Unilateral is more common than bilateral
Growths in the External Auditory Canal
Osteoma: Bony Tumor
Exostoses: outward projections for the surfaces of bone
External Otitis
An infection that occurs in the skin of the external auditory canal
Develops in people who have water trapped in their ears
Middle Ear
Carries vibrations from the outer ear to the inner ear by transferring the sound energy from the air in the outer ear to the fluids in the inner ear
Epitympanic Recess
Space in the middle ear above the tympanic membrane
Middle Ear Cleft
Eustachian Tube and Middle ear
Lined with mucous membrane
Endoterm
Middle ear space and Eustachian tube form from the pharyngeal arch which is lined with endoterm
Dilated epithelium lines these spaces