Scrub In. What is the function of cerumen? Which part of the ear collects sound waves and directs them into the auditory canal?

Transcription

1 Scrub In What is the function of cerumen? a. Keeps the ear canal from collapsing b. Helps transmit sound waves c. Protection d. Lubrication Which part of the ear collects sound waves and directs them into the auditory canal? a. Pinna b. Cohlea c. Tympanic membrane d. Malleus 1

2 3.04 Functions and disorders of the ear 2

3 Essential Questions What are the functions of the sensory system? What are some? How are sensory system disorders treated? How do you relate the body s communication to the sensory system? 3

4 Understanding the functions of the ear: Hearing 4

5 Understanding the functions of the ear External ear Pinna - collects sound waves External auditory canal - provides a passageway for sound traveling to the eardrum. It also protects the ear from infection. Contains cerumen (earwax) protects the ear Tympanic membrane (eardrum)- carries sound vibrations to the middle ear 5

6 Understanding the functions of the ear Middle ear Ossicles transmit sound waves from the ear drum to the inner ear Eustachian tube equalizes pressure in the middle ear with outside atmosphere 6

7 Inner ear Understanding the functions of the ear Cochlea is filled with fluid that vibrates when sound waves are transmitted by the stapes Semicircular canals located within the cochlea. contain liquid that is set in motion by head and body movements impulses sent to cerebellum to help maintain balance (equilibrium) 7

8 Understanding the functions of the ear Pathway of hearing external auditory canal tympanic membrane ossicles (malleus,incus,stapes) cochlea auditory nerve Decibels - measure sound based on human hearing 8

9 Understanding the functions of the ear Process of hearing: Sound waves enter the auditory canal and strike the eardrum, causing it to vibrate. The sound waves are then sent to the inner ear causing the stapes to vibrate which sets in motion the fluid of the cochlea. The alternating pressure changes disturb the delicate cells in the organ of Corti, moving the hair cells. This movement stimulates the sensory hair cells to transmit impulses through the auditory nerve to the brain. 9

10 Healthy Hearing How do you protect your hearing? What is the relevance to healthy hearing? 10

11 Understanding the functions of the ear Sound Activity What is a sound byte? Short bit of sound or clip from a longer recording. 11

12 Disorders of the ear 12

13 Disorders of the ear 13

14 Disorders of the ear External otitis (Swimmer's ear) - infection of the ear canal that can be caused by many different types of bacteria or fungi. Causes: ears that are exposed to moisture. Prevention: preventative ear drop solution, ear plug when you bathe or swim, drying ear canal with hairdryer 14

15 Disorders of the ear Otitis media Infection of the middle ear Often a complication of a common cold in children due to their eustachian tube being shorter and at more of a horizontal angle than adults. Treatment: antibiotics; if chronic or fluid builds up can do a Myringotomy (opening in the ear drum) with tubes inserted to relieve pressure 15

16 Disorders of the ear Otosclerosis Inherited disorder in which the stapes bone first becomes spongy then hardens. This causes the stapes to become unmovable. Oto- sclerosis Treatment: stapedectomy (total replacement of the stapes) 16

17 Disorders of the ear Meniere s disease Condition that affects the semicircular canals of the inner ear Symptoms: vertigo (dizziness), nausea, vomiting and tinnitus (ringing in the ear) Cause: unknown Treatment bed rest, medication to relieve vertigo and nausea 17

18 Disorders of the ear Tinnitus Ringing in the ear Explain this statement: Tinnitus is a symptom, not a disorder. 18

19 Disorders of the ear Presbycusis Condition that causes deafness due to the aging process Treatment: hearing aids 19

20 Disorders of the ear Conductive hearing loss sounds to the inner ear are blocked by ear wax or there is fluid in the middle ear Treatment: clean out ear wax, medication to help with fluid behind TM Sensorineural hearing loss damage to parts of the inner ear or auditory nerve Treatment: cochlear implants 20

21 Testing for hearing loss Rinne test Weber test Compares air and bone conduction hearing. Strike a tuning fork softly, place the vibrating tuning fork on the base of the mastoid bone, ask patient to tell you when the sound is no longer heard. Distinguishes between conductive and sensorineural hearing. Strike a tuning fork softly, place the vibrating fork on the middle of the client's head, ask patient if the sound is heard better in one ear or the same in both ears 21

22 Testing for hearing loss Normal results of Rinne and Weber test: Rinne test: if normal patient will note air conduction twice as long as bone conduction Weber test: if normal, the sound is symmetrical with no lateralization 22