Ear Flashcards
What is the function of the Pinna?
Receives sound waves and channels them into canal
What is the function of the auditory canal?
Conducts sound waves from the outside to eardrum
Has ceremoniousl glands which secrete ear wax, that traps dust and protect ear drum
What is the function of the tympanic membrane?
Converts sound waves into vibrations
What is the middle ear?
An air filled cavity lined with mucous membrane
What are the three membranes of Middle ear
Tympanic membrane
Oval window
Round window
What is the function of the tympanic membrane?
Covers opening between middle and outer ear
What is the function of the oval window?
Receives vibrations from stapes and transmits them to perilymph of inner ear
What is the function of the round window?
Spreads away vibrations of the perilymph back into air of Middle ear.
Prevents sound waves continuing around
What does the Middle ear consist of?
Tympanic membrane Oval window Round window Ossicles: - malleus - incus - stapes
What is the structure of malleus?
Attached to tympanic membrane
What is the structure of the incus?
Articulates with malleus and stapes
What is the structure of the stapes?
Articulates with incus and is attached to the oval window
What are the functions of the ossicles?
Transmit the vibrations across the middle ear from tympanic membrane to oval window
How are the vibrations amplified?
Tympanic membranes are larger than oval window
What is the function of the tiny muscles?
to protect inner ear from damage from loud noises
Why is it important that Eustachian tube lead into pharynx?
Allows air to enter into the middle ear to equalise pressure on either side if the tympanic membrane, so can vibrate easily
What are the 2 parts. The inner ear?
The vestibule for balance and lower cochlea for hearing
What is the fluid, perilymph?
Fill tiny canals and cavities of the bone.
What fluid is filled in the tiny tubes and acts of the perilymph?
Endolymph
What are the three parts of the vestibule?
Sacculus
Utriculus
Semi-circular canals
What are found in the sacculus and utriculus?
Patches of sensory cells -Maculae
What is important about the otoliths, that embed the hairs of the cells?
When move head, Gravity pulls on otoliths,causes hairs to bend
H do we know the position of our heads?
An impulses starts, passes along the equilibrium branch of auditory nerve into cerebellum of the brain.
What is the name of the ‘swelling’ at the end of the semi-circular canal
Ampulla
What are found in the Ampulla?
Patches of sensory cells - cristae
What is important about the cupola?
When we move endolymph moves and bends these hairs and initiates an impulse . Tell us the movement of our head
What are the 3 parts of the outer ear?
Pinna
Auditory canal
Tympanic membrane
