3.04 Functions and disorders of the ear

1. 3.04 Functions and disorders of the ear 3.04 Understand the functions and disorders of the sensory system

2. 3.04 Understand the functions and disorders of the sensory system • Essential Questions • What are the functions of the sensory system? • What are some disorders of the sensory system? • How are sensory system disorders treated? • How do you relate the body’s communication to the sensory system? 3.04 Understand the functions and disorders of the sensory system

3. Understanding the functions of the ear: Hearing 3.04 Understand the functions and disorders of the sensory system

4. Understanding the functions of the ear External ear • Pinna: collects sound waves and sends them to auditory canal • External auditory canal • Contains cerumen: protects ear (oily, wax like substance) • Tympanic membrane: separates outer and middle ear 3.04 Understand the functions and disorders of the sensory system

5. Understanding the functions of the ear Middle ear: cavity in the temporal bone Ossicles: transmits sounds waves from ear drum to inner ear 1. Hammer: malleus 2. Anvil: incus 3. Stirrups: stapes Eustachian tube: connects to the pharynx (equalizes pressure in the middle ear with the outside 3.04 Understand the functions and disorders of the sensory system

6. Understanding the functions of the ear Inner ear Cochlea: filled with fluid that vibrates when the sound waves from the stirrup bone strike against it Semicircular canals: liquid and hair like structures bend when set in motion by head and body movements  impulses sent to cerebellum; help maintain balance & equilibrium 3.04 Understand the functions and disorders of the sensory system

7. Understanding the functions of the ear Pathway of hearing Trace the pathway of hearing. Discuss the process of hearing. What are decibels? Sound measured in decibels (dB): faintest sound is labeled dB whereas a jet engine is 165dB. Exposure to anything over 90dB for 8 hrs may be dangerous to your hearing. 3.04 Understand the functions and disorders of the sensory system

8. Understanding the functions of the ear What is occurring at each structure? Review the pathway of hearing 3.04 Understand the functions and disorders of the sensory system

9. Healthy Hearing Listening to loud noises over a long period of time damage hair in the organ of Corti (cochlea). It destroys receptors and nerve cells and the damage is permanent. How do you protect your hearing? What is the relevance to healthy hearing? 3.04 Understand the functions and disorders of the sensory system

10. Understanding the functions of the ear Short bit of sound or clip from a longer recording. Sound Activity What is a sound byte? 3.04 Understand the functions and disorders of the sensory system

11. Disorders of the ear 3.04 Understand the functions and disorders of the sensory system

12. Disorders of the ear What instruments are used to examine the ear? What specialist studies the ears, nose, and throat? 3.04 Understand the functions and disorders of the sensory system

13. Disorders of the ear External otitis Discuss what you see in this picture? (Besides a Q-tip!) What causes external otitis? How can it be prevented? 3.04 Understand the functions and disorders of the sensory system

14. Disorders of the ear Normal tympanic membrane Otitis media Myringotomy Otitis media What is otitis media? Ear infection of middle ear Who is most at risk of having otitis media? Why? Children; eustachian tube is shorter so common colds create pressure because of fluid to build up behind the tympanic membrane What are the treatment options? Antibiotics or a myringotomy 3.04 Understand the functions and disorders of the sensory system

15. Disorders of the ear Otosclerosis • What is it? • Oto- sclerosis • Stapes bone becomes hard making it unmovable. Common cause of hearing loss in young adults. • What causes it? Inherited disorder • Why is a stapedectomy useful in treating otosclerosis? • Total replacement of the stapes 3.04 Understand the functions and disorders of the sensory system

16. Disorders of the ear Meniere’s disease What are the symptoms of Meniere’s disease? Vertigo (dizziness) What causes these symptoms? Pressure and swelling distorts balance info sent to the cerebellum How is it treated? Avoid salt, caffeine, nictoine. Medicines to treat dizziness and nausea. Bedrest and drinking plenty of water. 3.04 Understand the functions and disorders of the sensory system

17. Disorders of the ear Sign of hearing loss Tinnitus • What is tinnitus? • Ringing in ears Explain this statement: Tinnitus is a symptom, not a disorder. 3.04 Understand the functions and disorders of the sensory system

18. Disorders of the ear What is the difference between conductive hearing loss and sensory hearing loss? How can they be treated? Presbycusis What is presbycusis? Deafness due to aging Conductive hearing loss? Sounds to the inner ear are blocked by wax or fluid in the middle ear or abnormal bone growth Sensory hearing loss? Damage to inner ear or auditory nerves; treatment is cochlear implants 3.04 Understand the functions and disorders of the sensory system

19. Testing for hearing loss Rinne test Weber test Compare these two tests. How are they diagnostic? 3.04 Understand the functions and disorders of the sensory system

20. 3.04 Understand the functions and disorders of the sensory system • Essential Questions • What are the functions of the sensory system? • What are some disorders of the sensory system? • How are sensory system disorders treated? • How do you relate the body’s communication to the sensory system? 3.04 Understand the functions and disorders of the sensory system

21. 3.04 Functions and disorders of the ear The End 3.04 Understand the functions and disorders of the sensory system