Hearing Flashcards
Three sections of ear
outer, middle, inner
the structure that we normally think of as the ear, on the outside
Pinna/auricle
two purposes of pinna
funnel sound energy and aiding localization of sound in space
curled outer part of pinna
Helix
two ends of the superior part of antihelix after it splits in two
Crura of antihelix
entrance to ear canal
concha
another name of ear canal
External auditory meatus (EAM)
Medial point of auricle, when pressed down can cover the concha
Tragus
most inferior dangly bit of auricle
lobule
another name for eardrum
Tympanic membrane (TM)
another name for ear wax
Cerumen
Protects TM from dirt and insects via hairs and cerumen
ear canal
marks boundary between outer and middle ear
TM
what are the three layers of the tympanic membrane made of?
Outer = epithelial from EAM
Middle = fibrous tissue, makes structure (actually 2 layers)
Inner = lining of middle ear
portion of TM on the bottom that reflects light back to doctor
Cone of light
“tucking” point of helix
Crus of helix
what are the names of the three layers of the TM?
cuticular (outer)
fibrous (middle)
mucous (inner)
bones of ear known as
ossicles
Three bones that form ossicular chain
Malleus
Incus
Stapes
what is the purpose of the ossicular chain?
transmit acoustic energy to inner ear
malleus bone
middle ear bone nicknamed anvil
incus
incus
this middle ear bone is nicknamed “stirrup”
stapes
Ossicular chain held in place by
ligaments
Two muscles of inner ear (smallest in body)
Stapedius
Tensor tympani
what is the function of the stapedius muscle?
rotates stapes to stiffen ossicular chain
the tympanic muscles ____ ossicular motion to protect the ears
inhibit
stapes
what is the function of the tensor tympani muscle?
pull malleus to stiffen ossicular chain
activation of the stapedial muscle turns on after 85 dB, and is known as the
acoustic reflex