1. Anatomy Physiology and Disorders of the Hearing

2. Major Divisions of the Ear
Peripheral Mechanism
Central Mechanism
Outer Ear
Middle Ear
Inner Ear
VIII Cranial Nerve
Brain

3. Question What is the purpose of the pinna? A. Cosmetics
B. Sound collector
C. Same side localization
D. A and B
E. B and C

4. Outer/External Ear Pinna External Auditory Meatus Auricle=Pinna
Cerumen=Wax
External Auditory Meatus= Hole in temporal bone (leads to Auditory canal)
Tympanic Membrane-ear drum
Pinna
External
Auditory
Meatus

5. Pinna

6. Question
Another name for pinna? A. External auditory meatus B. External auditory canal C. Ear lobe D. Auricle E. None of the above

7. Function of Outer Ear Collect sound Localization Resonator Protection
Sensitive (earlobe)
Other?

8. Pinna localizes Directs sound into the ear
Each individual's pinna creates a distinctive imprint on the acoustic wave traveling into the auditory canal

9. Question
Cerumen should be routinely removed from the ear canal? A. True B. False

10. Cerumen
Repel water
Trap dust, sand particles, micro-organisms, and other debris
Moisturize epithelium in ear canal
Odor discourages insects
Antibiotic, antiviral, antifungal properties
Cleanse ear canal

11. Tympanic Membrane Separates outer from the middle ear
Protective barrier to the middle ear
Cone-shaped (depressed inward)
1st to vibrate in response to sound waves.

12. External Ear Care Hazardous to health: Ear candling Swabs
Foreign objects

13. Outer Ear Hearing Disorders
CHARGE
Down Syndrome
Ears small and low set
Fetal Alcohol Syndrome
Deformed ears

14. Grow Ear?

15. The big picture
Size and shape

16. What is sound?
Sound is a form of energy that can be heard and travels in waves.
When matter vibrates or moves back and forth very quickly, a sound is made.
Sound waves can travel through solids, liquids, or gases.

17. Sound makes the air vibrate.
For sound to be heard, sound vibrations must have air or some other kind of matter to travel through.
Can’t hear sound in outer space because there is no air or other matter to carry sound vibrations.

18. Middle Ear The function of the middle ear is to?
A. Cause middle ear infections in young children
Amplify sounds
Interpret sounds
Analyze sounds
None of the above

19. Middle Ear What are the parts of the middle ear? Ossicles and cochlea
Ossicles and eustachian tube
Tympanic membrane and auricle
I don’t know

20. Middle Ear
Ossicles
Middle Ear Muscles
Eustachian Tube
Mastoid

21. Function of Middle Ear Conduction
Conduct sound from the outer ear to the inner ear
Protection
Creates a barrier
Transducer
Converts sound waves to mechanical energy
Amplifier

22. Middle Ear (parts)
Auditory Ossicles - malleus, incus, stapes - transmit vibrations and amplify the signal
Eustachian tube- connects the middle ear to the throat - helps maintain air pressure

24. Eustachian Tube Connects the middle ear with the nasopharynx
Opens during swallowing and yawning
This equalizes the pressure on either side of the eardrum
Necessary for optimal hearing.
Without this function the eardrum could prolapse.
Plugged ears on a plane

25. The Eustachian tube: Opens when one yawns Opens when one smiles
Opens when one blinks
It is always open
Never opens

26. Ossicles Malleus (hammer) Incus (anvil)
Stapes (stirrup) smallest bone of the body

27. Middle Ear Disorders Middle Ear disorders Acute otitis media
TM Perforation

28. Question The function of the inner ear: Balance Hearing Touch
All the above
A and B

29. Inner Ear = Labyrinth
Labyrinth series of fluid filled tubes responsible for equillibrium (balance) and hearing.
Made of 2 main regions: Semicircular canals & Cochlea
Semicircular Canals - sense of equilibrium
Cochlea – senses hearing
Organ of Corti - contains hearing receptors, hair cells detect vibrations

30. Organ of Corti

31. Inner Ear: Cochlea
Inside the cochlea are special neurons called HAIR CELLS
The stapes is attached to the OVAL WINDOW, and vibrations cause the fluid in the inner ear to vibrate
This moves the hair cells, transmitting the vibration.
Therefore the HAIR CELLS in this region are receptors for HEARING.
As you age, hair cells become damaged (loud music can speed this process along). Older people usually can’t hear frequencies that younger people can hear.

33. Sense of Equilibrium
Static Equilibrium - sense the position of the head, maintain stability and posture
Dynamic Equilibrium (semicircular canals) - balance the head during sudden movement
Cerebellum (brain)- interprets impulses from the semicircular canals and maintains overall balance and stability

34. Steps in Hearing
1. Sound waves enter external auditory meatus 2. Eardrum vibrates 3. Auditory ossicles (malleus, incus, stapes) amplify vibrations 4. Stapes hits oval window and transmits vibrations to cochlea 5. Organs of corti contain receptor cells (hair cells) that deform from vibrations 6. Impulses sent to the vestibulocochlear nerve 7. Auditory cortex of the temporal lobe interprets sensory impulses 8. Round window dissipates vibrations within the cochlea