Anatomy of the Ear Flashcards
How many sections of the ear are there?
Three
What are the three regions of the ear called?
Outer(Externa)
Middle
Inner
What part of the ear is involved wth balance?
The inner ear including the vestibular tubes
What components are found in the outer ear?
Auricle(Pinna)
Ear canal
What is the function of the auricle(pinna)?
It captures and directs sound waves towards the ear canal
What is another name for the ear canal?
External Acoustic Meatus
Where is the tympanic membrane found?
It lies at the end of the ear canal and separates the outer and middle ear
What is the tympanic membrane made of?
Mucous membrane and skin
What happens to the tympanic membrane when sound waves enter?
Vibrates to the changes in air pressure.
The sound energy is transmitted to the malleus and subsequently to the other bones within the middle ear
What are the features of a healthy tympanic membrane?
Pearly grey/pink
Slightly translucent
Which of the ossicles does the tympanic membrane attatch to?
Malleus
What is another name for the tympanic membrane?
Ear drum
What does the middle ear consist of?
It is an air-filled section containing auditory ossicles
Eustachian tube
Oval window
What are ossicles?
Tiny bones in the ear
What are the three ossicles called?
Malleus, Incus, Stapes
Where is the middle ear?
Between the tympanic membrane and the wall of the inner ear
Are the three ossicles connected to each other?
Yes
Which order are the three ossicles in?
Malleus
Incus
Stapes
What happens once the vibrations from the tympanic membrane reach the first ossicle?
The vibrations are transmitted accross the ossicles which then transmit the vibrations to the oval window
What is the oval window?
Membrane covering the entrance to the inner ear
How long is the eustachian tube in adults?
~18mm long
Where does the eustachian tube connect to?
The back of the throat
What is the function of the Eustachian tube?
Balances the air pressure on either side of the tympanic membrane
Drains fluid from the middle ear
What is the difference between an adult eustachian tube and a child eustachian tube?
The eustachian tube in a child is shorter, narrower and more horizontal than an adult
What two things does the inner ear control?
Hearing and Balance
What happens to the vibrations after they are transmitted to the oval window?
The vibrations are converted into electrical signals which are sent to the brain via the auditory nerve (choclear)
It is interpreted by the brain as sound
Describe the path that sound waves take from the pinna to the brain
The sound waves are captured by the auricle(pinna)
They are channeled to the external acoustic meatus(ear canal)
The sound waves cause the tympanic membrane(ear drum) to vibrate
These vibrations transfer through to the ossicles: malleus => incus => stapes
The stapes is connected to the choclea which converts the vibrations into electrical signals
These are transferred to the brain via the auditory nerve(choclear)
What part of the inner ear is most important for balance?
Vestibular apparatus
What are the vestibular apparatus?
A network of cooped tubes called semi-circular canals, the utricle and the saccule
What do the semi circular canals do?
Detect rotational movement through cells which activate as you tilt or move your head
What is the function of the utricle and saccule?
Detect linear movement and send signals to the vestibular nerve which joins the auditory nerve carrying signals to the brain
The brain interprets the signals and adjusts eyes and signals muscles to maintain balance
What is found in ear wax?
Cerumen
Dead skin cells
What does ear wax do?
Provides a protective film on the lining of the ear canal
Keeps ear canal clean
Lubricates and protects ear canal from infection
Traps dirt and repels water
Is ear wax slightly acidic or alkaline?
Acidic
What property does ear wax being slightly acidic provide?
Asceptic
How does the ear canal get rid of wax?
Epithelial migration, helped by jaw movement
Where is ear wax made?
Outer thirds of the ear canal
How many different types of secretory glands are there?
Two
What are the two types of secretary glands?
Sebaceous glands
Ceruminous glands
What do sebaceous glands produce?
Sebum
What do ceruminous glands produce?
Sweat
What are some symptoms of excessive ear wax?
Decrease in hearing
Feeling of fullness in canal
Pain
Ringing in ears
Odour
Dizziness
Cough
Itchiness
Procucts available to treat ear wax?
Sodium Bicarbonate
Olive oil
