1. Copyright © 2009 Pearson Education, Inc. Chapter 12 Sensory Mechanisms  Types of receptors  Somatic senses  Special senses

2. Copyright © 2009 Pearson Education, Inc. Table 12.1 (1 of 2) Types of Receptors

3. Copyright © 2009 Pearson Education, Inc. Table 12.1 (2 of 2) Types of Receptors

4. Copyright © 2009 Pearson Education, Inc. Figure 12.1 Sensory Receptors in Skin Free nerve endings Thermo-, light touch, and pain receptors Modified and encapsulated nerve endings Merkel disks: light touch Hair Free nerve endings: sense changing position of hairs Meissner’s corpuscle: light touch Pacinian corpuscle: deep pressure and high- frequency vibration Ruffini endings: pressure Epidermis Subcutaneous layer Dermis

5. Copyright © 2009 Pearson Education, Inc. Special Senses- Taste  Taste buds  Chemoreceptors that bind with dissolved substances  Taste categories  Sweet  Salty  Sour  Bitter  Umami

6. Copyright © 2009 Pearson Education, Inc. Figure 12.5d Locations and Structure of the Receptors for Taste

7. Copyright © 2009 Pearson Education, Inc. Smell  Olfactory receptor cells  Chemoreceptors that bind with odorants  Correlation between taste and smell  Chewed food releases chemicals that come in contact with olfactory receptors

8. Copyright © 2009 Pearson Education, Inc. Figure 12.6 Olfactory Receptors and the Mucus- Producing Olfactory Glands

9. Copyright © 2009 Pearson Education, Inc. Hearing  Mechanoreceptors detect sound waves

10. Copyright © 2009 Pearson Education, Inc. Figure 12.9 Structure of the Human Ear

11. Copyright © 2009 Pearson Education, Inc. Table 12.3 Structures and Functions of the Ear

12. Copyright © 2009 Pearson Education, Inc. Figure 12.10 Structures and Function of the Cochlea

13. Copyright © 2009 Pearson Education, Inc. Balance: Inner Ear  Specialized structures of inner ear  Vestibular apparatus  Three semicircular canals and vestibule  Sensing rotational movement  Ampulla with mechanoreceptors in cupula  Sensing head rotation and acceleration  Uticle and saccule in vestibule with otoliths

14. Copyright © 2009 Pearson Education, Inc. Figure 12.13a–c Sensing Head Position and Acceleration

15. Copyright © 2009 Pearson Education, Inc. Vision  Detecting and interpreting visual stimuli by converting light energy to nerve impulses and transmitting them to the brain  Structures  Sclera and cornea  Aqueous humor, iris, lens  Vitreous humor, retina, optic nerve  Fovea centralis, optic disc

16. Copyright © 2009 Pearson Education, Inc. Figure 12.14 Structure of the Eye Canal of Schlemm Iris Lens Pupil Cornea Aqueous humor Ciliary muscle Sclera Choroid Vitreous humor Retina Fovea Optic disk Optic nerve

17. Copyright © 2009 Pearson Education, Inc. Table 12.4 Parts of the Eye and Their Function

18. Copyright © 2009 Pearson Education, Inc. Regulating Light and Focusing  Focusing (continued)  Eye shape  Normal shape allows focusing at fovea  Myopia: eye longer, nearsighted  Hyperopia: eye shorter, farsighted  Astigmatism: irregularities in cornea or lens

19. Copyright © 2009 Pearson Education, Inc. Figure 12.16a Examples of Abnormal Vision

20. Copyright © 2009 Pearson Education, Inc. Figure 12.16b Examples of Abnormal Vision

21. Copyright © 2009 Pearson Education, Inc. Figure 12.16c Examples of Abnormal Vision

22. Copyright © 2009 Pearson Education, Inc. Figure 12.16d Examples of Abnormal Vision

23. Copyright © 2009 Pearson Education, Inc. Figure 12.17 Structure of the Retina

24. Copyright © 2009 Pearson Education, Inc. Disorders of Sensory Mechanisms  Disorders of the ear  Deafness  Nerve  Conduction  Otitis media  Inflammation of the middle ear  Ménière’s syndrome  Inner ear condition impairs hearing and balance

25. Copyright © 2009 Pearson Education, Inc. Disorders of Sensory Mechanisms  Disorders of the eye  Retinal detachment  Retina separates from choroid  Cataracts  Lens becomes opaque  Glaucoma  Pressure inside the eye rises  Color blindness  Inability to distinguish the full range of colors