1. The Auditory System, Olfaction, Gustation, and Somothesis

2. Hearing: The Nature of Sound

3. Sound Sound, like light, comes in waves Sound is vibration

5. Hearing: The Structure of the Auditory System

6. Parts of the Ear – Sound Waves

7. Auditory Canal The opening through which sound waves travel as they move into the ear for processing Ends at the tympanic membrane (eardrum)

8. Parts of the Ear – Auditory Canal

9. Tympanic Membrane (eardrum) The tissue barrier that transfers sound vibration from the air to the tine bones of the middle ear Can be damaged by objects in the ear or exceptionally loud noises

10. Parts of the Ear – Tympanic Membrane

11. Ossicles Three tiny bones that transfer sound waves from the eardrum to the cochlea Hammer, anvil and stirrup

12. Parts of the Ear - Occicles

13. Cochlea The major organ of hearing A snail shaped bony body tube fluid- filled in the inner ear Sound waves are changed to neural impulses

14. Parts of the Ear - Cochlea

15. Oval Window The point on the surface of the cochlea which receives the sound vibration from the ossicles As the oval window vibrates, the fluid in the cochlea vibrates.

16. Parts of the Ear – Oval Window

17. Hair Cells The receptor cells for hearing Located in the cochlea Responsibly for changing sound vibrations into neural impulses Similar to the rods and cones within the eye

18. Parts of the Ear - Hair Cells

19. Auditory Nerve The nerve that carries sound information from the ears to the temporal lobes of the brain

20. Parts of the Ear – Auditory Nerve

21. Semicircular Canals Organs in the inner ear used in sensing body orientation and balance (vestibular sense) Relies on fluid in the canals Spinning in circles disrupts the fluid.

22. Parts of the Ear – Semicircular Canals

23. Other Senses: Taste

24. Taste Taste is a chemical sense. Receptor cells are located primarily on the tongue and in the mouth. Four different tastes: –Salty, sweet, sour and bitter Damaged taste receptor cells are replaced within a few days.

25. Supertasters People with an abundance of taste receptors Approximately 25% of the population

26. Nontasters People with a minimum of taste receptors Taste with less intensity than the rest of the population Approximately 25% of the population

27. Other Senses: Smell

28. Smell Smell is a chemical sense. Olfactory cells in the upper nasal passages detect molecules in the air. Taste and smell interact to produce flavor.

29. Other Senses: Touch

30. Touch Touch receptors are on the skin Four basic skin senses are –Pain, warmth, cold, and pressure All skin sensations are a combination of these four basic senses

31. Figure 8.15 When Is Hot Not? Blair-Broeker and Ernst: Thinking About Psychology, Second Edition Copyright © 2008 by Worth Publishers

32. Gate-control Theory of Pain Pain messages travel on one set of nerve fibers containing pain gates. The gates are open when pain is felt. Other sensory messages go through another set of fibers. The nonpain fibers can close the pain gates to stop the sense of pain.