Download - The Human Ear
The Human Ear
The Human Ear
• Composed of outer, middle and inner ear
The Outer Ear
• The visual part of the ear
• Composed of pinna and auditory canal
• The pinna acts as a funnel, collecting sound waves and directing them to the auditory canal
The Outer Ear
• The auditory canal transfers the waves to the middle ear
• Although humans can hear from 20 Hz to 20000 Hz, the auditory canal amplifies waves in the range of 1000 Hz to 5500 Hz
The Middle Ear
• The middle ear begins with the tympanic membrane
• Compressions push the tympanic membrane in, rarefactions pull it out
The Middle Ear
• The hammer, anvil and stirrup transfer the motion of the tympanic membrane to the inner ear, at the oval window
The Inner Ear
• The waves from the oval window cause waves in the cochlea, which is filled with fluid
• The waves travel through the cochlea, stimulating the microscopic hairs
The Inner Ear
• Each hair is attached to a nerve cell; when stimulated the wave is turned into electrical energy and that signal is sent to the brain this is what we “hear”
Why do my ears pop?
• The Eustachian tube is part of the middle ear and connects it to the mouth
• This tube opens when we swallow or yawn, equalizing the air pressure inside the middle ear
Why can an ear infection make me dizzy?
• The semicircular canals are located in the inner ear
• These canals are filled with fluid and are at approximately right angles to each other
• They transmit information to the brain about balance
How can someone pop their eardrum?
• This is called a perforated or ruptured eardrum
• Often the result of an ear infection – fluid builds up and causes a tear in the tympanic membrane
• The person feels a sharp pain and fluid drains from the ear
• The hearing loss is usually temporary, as the membrane often heals itself
How can someone pop their eardrum?
• You can also perforate / rupture your eardrum by poking it, sudden extreme air pressure changes, very loud noises, head injuries
What is earwax for?
• Earwax is made in the auditory canal
• The skin cells there have glands to produce earwax
• It’s called cerumen
What is earwax for?
• Earwax has several jobs:
1. Protects and moisturizes the skin in the ear canal
2. Fight infections
3. Shields the eardrum from the outside world
