the human ear
DESCRIPTION
The Human Ear. Composed of outer, middle and inner ear. The Human 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. - PowerPoint PPT PresentationTRANSCRIPT
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