Ears

1. Ears 1

2. Warm up What is the condition called where the eye is egg shaped instead of round? What is the colored portion of the eye? What is the window of the eye? What does the conjunctiva line? Where is the optic disk located? What lies directly behind the pupil? What colors are difficult to see if you are color blind? If you could not see well at night, what eye structure would be impaired? What is the eye condition called where the lens is cloudy? What eye disorder would you have if your central vision was distorted or dark?

3. Structure and functions of the ears

4. Structures of the ears • External ear • Middle ear • Also known as the tympanic cavity • Inner ear • Also known as the labyrinth 4

5. Understanding the structures and functions of the ear External ear PINNA (AURICLE) – outer ear, collects sound waves EXTERNAL AUDITORY CANAL – ear canal CERUMEN – earwax, protects the ear TYMPANIC MEMBRANE – ear drum, separates outer and middle ear

6. Understanding the structures and functions of the ear Middle ear • Cavity in temporal bone • Connects with pharynx by EUSTACHIAN TUBE – which equalizes pressure in the middle ear with outside atmosphere • Ossicles- Bones in middle ear that transmit sound waves from ear drum to inner ear • MALLEUS (hammer) • INCUS (anvil) • STAPES (stirrup)

7. Understanding the structures and functions of the ear Inner ear Contains spiral shaped organ of hearing – the COCHLEA The cochlea contains a membranous tube, the cochlear duct – which is filled with fluid that vibrates when sound waves are transmitted by the stapes

8. Understanding the structures and functions of the ear Inner ear ORGAN OF CORTI – delicate hairlike cells that pick up vibrations of fluid and transmit them as a sensory impulse along the auditory nerve to the brain SEMICIRCULAR CANALS – three structures in the inner ear, contain liquid that is set in motion by head and body movements – impulses sent to cerebellum to help maintain body balance (equilibrium)

9. Ears Name the structures… Review 9

10. Pathway of Hearing Sound Outer Ear External Auditory Canal Tympanic Membrane Ossicles (malleus, incus, stapes) Oval Window Cochlear- Organ of corti Auditory Nerve Brain- Cerebral cortex

11. Decibles A measurement of sound level https://www.youtube.com/watch?v=uAd2BUB6XqQ Hearing Activity- Name the following sounds on your handout http://www.crickweb.co.uk/ks1science.html#sound1f 3.04 Understand the functions and disorders of the sensory system

12. Healthy Hearing How do you protect your hearing?

13. Disorders of the ear

14. Disorders of the ear What instruments are used to examine the ear? What specialist studies the ears, nose, and throat?

15. Disorders of the ear External otitis • Cause- Commonly known as “swimmer’s ear” • Infection in the external auditory canal- bacterial or fungal • Symptoms- Fever, pain in ear and decreased hearing or loss. • Treatment- Antibiotic drops

16. Disorders of the ear Normal tympanic membrane Otitis media Myringotomy Otitis media • Cause- Infection of the middle ear. Often a complication of a common cold in children • Symptoms- Fever, ear pain, pus. Child will pull at ears. Can be one side or both. • Treatment- antibiotics • If chronic or if fluid builds up – MYRINGOTOMY (opening in the tympanic membrane) with tubes inserted will relieve the pressure

17. Disorders of the ear Normal tympanic membrane Otitis media Myringotomy Otitis media http://www.medicinenet.com/anatomy_of_an_ear_infection_pictures_slideshow/article.htm

18. Disorders of the ear Otosclerosis Cause- Excess bone growth in the middle ears- usually the stapes- Hereditary- Hardening Symptoms- Decreased hearing and sometimes deafness. Treatment- Stapedectomy- replacing the stapes with a plastic or wire implant.

19. Disorders of the ear Otosclerosis

20. Disorders of the ear Meniere’s disease Cause- abnormal volume or composition of fluid in the inner ear labyrinith. Symptoms- Vertigo, hearing loss, tinnitus Treatment- No cure. Motion sickness medications, nausea medicine.

21. Disorders of the ear Tinnitus- ringing in the ears. It’s a symptom not a disorder. Can be caused by loud noises

22. Disorders of the ear What is the difference between conductive hearing loss and sensory hearing loss? How can they be treated? Presbycusis (Hard of Hearing) Cause- Degeneration of the inner ear. Gradual hearing loss in both ears due to aging. Symptoms- Loss of hearing especially high pitched sounds, women’s voices, tinnitus. Treatment- Hearing aids

23. Disorders of the ear Conductive Hearing Loss- occurs when there is a problem conducting sound waves anywhere along the route through the outer ear, tympanic membrane (eardrum), or middle ear (ossicles).- Ear wax impacted in ears

24. Disorders of the ear Sensorineural Hearing Loss-  a type of hearing loss in which the root cause lies in the vestibulocochlear nerve, the inner ear, or central processing centers of the brain. Sensorineural hearing loss can be mild, moderate, or severe, including total deafness. Can happen during development or nerve damage after birth.

25. Testing for hearing losshttp://www.youtube.com/watch?v=7BQFKnP-7Qg Rinne test Weber test Compare these two tests. How are they diagnostic?

26. Processing • Labeling #3

27. Structure, Functions and Disorders of the Ear The End