Sponge: Set up Cornell Notes on pg. 55 Topic: 12 Sponge: Set up Cornell Notes on pg. 55 Topic: 12.6: Middle Ear Essential Questions: The tympanic reflex is a protective mechanism for hearing, what CAN’T it protect against? 12.6: Middle Ear 2.1 Atoms, Ions, and Molecules

Middle Ear

Our Amazing Hearing (4m32s) P. 54 Take 5 bullets

Tympanic cavity air-filled space in temporal bone

Middle Ear Auditory ossicles 3 small bones that vibrate in response to ear drum Transmit vibrations between the tympanic membrane and the inner ear 1. Tympanic membrane vibrates the malleus  2. Malleus (hammer) vibrates the incus  3. Incus (anvil) vibrates the stapes  4. Stapes (stirrup) vibrates against the oval window  5. Oval window moves fluids in inner ear which stimulate the hearing receptors Malleus Stapes Incus

Pg. 54 Incus Malleus Oval window Stapes Tympanic membrane Color code (Anvil) Malleus (Hammer) Oval window Stapes (Stirrup) Tympanic membrane

How the Ear Works (3m25s) P. 54 Take 3-5 bullets http://www.youtube.com/watch?v=qgdqp-oPb1Q

Middle Ear Tympanic reflex is elicited in about 1/10 of a second following a loud external sound 2 small skeletal muscles contract, reducing the effectiveness in transmitting vibrations to the inner ear Reduces pressure from loud sounds that might otherwise damage the hearing receptors BUT, it cannot protect hearing receptors from loud sounds which occur rapidly Ex: explosion, gun shot

Auditory Tube Auditory Tube aka Eustachian Tube Connects middle ear to throat Allows air to pass between the tympanic cavity and the outside of the body by way of the throat and mouth Helps maintain equal pressure on both sides of tympanic membrane Necessary for normal hearing Usually closed by valve-like flaps in throat

Auditory Tube Noticeable during rapid change in altitude Ex: High to low altitude Air pressure on outside of tympanic membrane increases Tympanic membrane is pushed inward, impairing hearing Air will force its way up into the middle ear This equalizes the pressure on both sides of the tympanic membrane, moving it back into its rightful position Causes a “popping” sound Swallowing, yawning, or chewing aid in the opening of the valves and can hasten equalization of air pressure

12.6: Middle Ear Infections Sponge: Set up Cornell Notes on pg. 57 Topic: 12.6: Middle Ear Infections Essential Questions: What is the major cause of middle ear infections? What are some complications of ear infections? 12.6: Middle Ear Infections 2.1 Atoms, Ions, and Molecules What is the major cause of middle ear infections? What are some complications of ear infections?

Otitis Media “Ear Infection” Otitis Media aka “Middle ear infection” Fluid builds up in middle ear Breeding ground for bacteria, which causes infection The mucous membranes that line the auditory tubes connect with the linings of the middle ear which creates a conduit for bacteria infecting the throat or nasal passages Greater in young children Usually treated with antibiotics

Pg. 56 Pictures Pictures Pictures Pictures Otitis Media Symptoms Causes Consequences Treatment Pictures Pictures Pictures Pictures

Symptoms Ear Infection Symptoms The main warning sign of infection is sharp ear pain. You may be especially uncomfortable lying down, so you might have a hard time sleeping. Other problems to look for: Trouble hearing Fever Fluid oozing from ears Dizziness Stuffy nose

Causes Fluid in the Ear If the Eustachian (auditory) tube gets blocked, fluid builds up inside middle ear. This makes the perfect breeding ground for bacteria and viruses, which can cause infections. Your doctor will look inside your ear with an otoscope, which can blow a puff of air to make his eardrum vibrate. If the eardrum doesn’t vibrate as much as it should, chances are there’s fluid inside.

Possible Consequences 1. Bursting an Eardrum If too much fluid or pressure builds up inside your middle ear, the eardrum can actually burst (shown here). If that happens, you may see yellow, brown, or white fluid draining from the ear. Although this sounds scary, the eardrum usually heals itself in a couple of weeks. Unless it happens a lot, your hearing should be fine. The good news is that the pain may suddenly disappear because the hole lets the pressure go

2. Hearing Loss If ear infections keep coming back, they can scar his eardrums and lead to hearing loss, speech problems, or even meningitis. If a person suffers from infections often, they might want to have their hearing tested just in case.

Treatment Options Antibiotics using antibiotics both topical and oral can provide you relief from earache by fighting the infection, as they stop swelling and itching of the ear.

Treatment Options 2. Myringotomy- An incision is made in the tympanic membrane Tympanostomy tubes aka “ear tubes” are Inserted into affected ears during surgery Form a small tunnel so ears can drain Tubes usually fall out on their own Hopefully the child has outgrown the susceptibility to ear infections *This is only used in cases of chronic ear infections

Tympanostomy Tubes 1m 34s http://www.youtube.com/watch?v=iFLRR1j9Ps4

Tonsils Can Be the Cause Sometimes a child’s tonsils get so swollen that they put pressure on the Eustachian tubes connecting her middle ear to her throat -- which then causes infections. If that keeps happening, the tonsils may have to be taken out

Use the video and the “All About Ear Infections” reading to add to your Otitis Media Tree-Map DON’T forget to add pictures! I want a FULL Tree-Map

Otitis Media Video 4m30s http://www.youtube.com/watch?v=UBobShigoFk