The ear Flashcards
What is the outer ear called?
Whats it made of?
The pina or the aricle
Cartlilidge
What do glands in the ear canal produce?
Ear wax creumen
What is the purpose of the pina?
To collect sound into the ear cannal
What seperates the ecternal ear from the middle ear?
The timpanic membrane
What are the 3 bones?
Collective term?
What do they do?
Malleus, incus, stapes
Ossicles
convert sound waves into mechanical vibrations
What is attatched to the surface of the timpanic membrane in the middle ear?
Handle of the malleus
Where are the ossicles fits in to to the oval window?
The foot of the stapes
Because the area of the tympanic membrane is _______than the area of the oval window the energy in the vibrations is ________
as it passes from middle to inner ear. .
Because the area of the tympanic membrane is larger than the
area of the oval window the energy in the vibrations is amplified
as it passes from middle to inner ear. .
What are the 2 parts of the inner ear and what are they for?
Vestibular apparatus for balance
cochela for hearing
What are 3 purposes of the muddle ear?
Transfer eneregy to the inner ear
protect the inner ear
equalisation of air pressure
Where is the esutachian tube?
middle ear to nasopharynx
What does the eustacian tube do and why does this help hearing?
Equalises pressure on both sides of the ear drum
Leads to maximum transfer of sound vibrations through middle ear
Describe the structure of the cochella?
- Spiral shaped
- fluid filled
Where is the temporal bone?
What are the tunnels and chambers inside the temporal bone called?
Bony labyrinth
What inside the bony labyrinth?
Membraenous labyrinth
What are the 3 reigons of the bony labyrinth?
The cochlea, vestiblue and semicircular canal
What are the 3 canals in the membranous labyrinth?
What are they filled with?
Vestibular (upper) / perilymlph
scala media/ cochelar duct / endolymph
tympanic duct / perilymph
Where does the scala vestibuli extend from?
The oval window to the helicotrema
Where does the scala tympani extend from and too?
The round window to the helicotrema
The cochlea is filled with a watery liquid, the ___________, which moves in response to the vibrations coming from the middle ear via the ________.
Perilymph
oval window
As the fluid moves, the cochlear partition (_______membrane and organ of _____) moves; thousands of hair cells sense the motion via their ________, and convert that motion to ____________that are communicated via neurotransmitters to many thousands of nerve cells
basilar membrane and organ of Corti
stereocilia,
electrical signals
What nerve do the hair cells excite?
The vestibulocochlear nerve
What are the 3 main inputs to the brain that contribute to our sense of balance?
Vestibular
Visual
Somatosensory/proprioceptive
Where in the brain is the balance system intergrated?
Brainstem and cerebellum
What are the two structures in the vestibular system?
3 semicircular cannals
2 otolith organs (utricle and saccule)
What part of the inner ear provides us with a sense of linear moovment?
The utricle and saccule
What part of the inner ear provides us with a sense of angular moovment?
the semi-curcular cannals
Where in the semi circular cannal is the sensory aparatus contained?
What is it called?
in a bulge (ampulla) at the end nearest the utricle
Cistra
When head movement takes place the fluid in the canal moves, causing a deflection of the _____.
Cupula
This in turn deflects the _____of the receptor cell and initiates the _________.
Cilla, nerve impulse
Linear movement
2 fluid filled sacs adjacent to the semi-circular canals have within them areas of receptor cells that again have stereocilia at their surface (macula regions).
The stereocilia are embedded in a gel like material (_______________). On top of the _____membrane are tiny crystals called _________.
otolithic material
otolithic
otoconia
