Download The Ear: Hearing and Balance

The Ear: Hearing and Balance
Anatomy of the Ear
The ear is divided into 3 parts:
 the ________________ ear
 the ________________ ear
 the ________________ ear
The outer and middle ear structures are ______________________________________________.
The inner ear functions in both _____________________________________________________.
Outer (External) Ear
Made up of the _________________ and the _____________________________________.
The pinna is ____________________________________________________________________.
The shell-shaped structure surrounds the auditory canal.
The auditory canal is carved into the ______________________________.
In its skin-lined walls are _________________________________ that secrete a waxy, yellow substance
called ________________ or cerumen.
___________________________ that enter this canal eventually reach the tympanic membrane or
___________________ where they _________________________________.
The eardrum separates the outer ear from the middle ear.
The Middle Ear
It is bordered:
 ____________________by the _____________________
 ____________________by a bony structure with 2 openings
The structures of the middle ear are:
 The ________________________________
 The _________________ (three small bones)
The Eustachian tube (AKA: the auditory tube) runs obliquely downward to link the ___________________
with the ____________.
Typically, this tube is ___________________ and closed, but yawning or swallowing can temporarily open
it up.
Doing this will _____________________________________________ within the middle ear to that of
external environment.
 This is important, because when the ____________________________________________, the
eardrum ___________________________________; this causes hearing difficulty and often earaches.
The middle ear also houses the 3 smallest bones (________________) in the body.
The ossicles ______________________________________________________ from the eardrum to the
fluid within the inner ear.
Each of these bones has 2 names apiece:
 _________________ or malleus
 _______________ or incus
 _________________ or stapes
Transmitting Sound
When the _____________________________, the _________________ moves with it.
The _________________ transfers the vibrations to the ______________.
The anvil next passes the vibrations onto the _________________ which presses on the oval window.
Movement at the __________________________ sets the fluids in the inner ear into motion, and this is
perceived by nerves called ________________________________.
The Inner Ear
The inner ear is made up of a combination of parts known as the bony labyrinth.
These bones lie deep within the temporal bone just behind the eye socket.
There are 3 subdivisions to the bony labyrinth:
 The ________________ (for hearing)
 The _____________________ (the connector)
 The ___________________________ (for equilibrium)
The Cochlea
The special __________________________________ is the cochlea
The cochlea is a (curled up) tube _____________________________________
and lined with ______________________________________________ that pick up the fluid vibrations
transmitted by the ossicles.
Nerve impulses are created and then transmitted through the _______________________________ nerve
to the hearing center of the brain.
Pathway of Hearing
Sound waves → ________________ → ____________________________ → tympanic membrane →
ear ________________ → vibrations stimulate the receptors in the _______________ → nerve signals
travel through (auditory part of) the vestibulocochlear nerve) → ___________________________ of the
brain for interpretation.
The Semicircular canals
____________________________________________________ are 3 semicircular canals.
They also filled with liquid and are lined by nerve cells.
The liquid and neurons identify when there is ________________ of the ____________ or of the
____________.
An impulse is then sent to the ___________________ helping to maintain body ____________________.
Pathway of Equilibrium
Movement _____________ → stimulates nerve cells in the ___________________________________
of the inner ear → nerve signals travel through (vestibular part of) the vestibulocochlear nerve →
____________________ of the brain for interpretation.