The Human Ear Flashcards
What are the 2 functions of the ear?
- Mediates the sense of hearing
2. Mediates the sense of balance
What are the 3 sections of the ear?
- Outer ear or ear canal
- Middle ear
- Inner ear
What does the outer ear consist of?
- Flap of cartilage framing a 25mm long canal that terminates at the eardrum
What is the ear canal made up of?
- Obstacle course of hairs
- About 4,000 wax producing cells
What is the purpose of the wax-producing cells in the ear canal?
- Prevent intrusions such as insects or dust from reaching the eardrum
- Protects eardrum from extreme heat and cold
If too much wax is produced what can be done?
- Can be assessed and removed by a doctor with a syringe
As the eardrum vibrates to sound waves arriving by the canal, 3 tiny bones; the hammer, anvil and stirrup…
Amplify and conduct those vibrations to the cochlea
The stirrup connects to the cochlea at a location called the….
Oval window
What happens at the oval window?
The mechanical energy of vibration is converted to electrical energy of nerve impulses which are carried to the brain via the cochlear nerve
the middle ear is vented to the atmosphere via what?
The eustachian tube which connects to the upper throat
Parts of the middle ear?
- Eardrum
- The hammer
- Anvil
- Stirrup
- Oval window
- Cochlea
- Cochlear nerve
- Eustachian tube
What is mounted above the cochlea in the inner ear?
- Semicircular canals
What do the semicircular canals do?
- Detect acceleration in pitch, roll, and yaw
What is the cochlea?
A tiny bone structure that looks a little like a snails shell
What is the cochlea filled with?
- Fluid called Endolymph
- Hair like cells
the hairlike cells in the cochlea respond to pressure waves and generate what?
- Nerve impulses which the brain interprets as sound
What does constant exposure to loud noise do to the hairlike cells?
Damages them
Is the damage to hairlike cells from exposure to loud noise reversible?
No