1. Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Fundamentals of Anatomy & Physiology SIXTH EDITION Frederic H. Martini PowerPoint ® Lecture Slide Presentation prepared by Dr. Kathleen A. Ireland, Biology Instructor, Seabury Hall, Maui, Hawaii Chapter 17, part 1 The Special Senses

2. Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Learning Objectives Describe the sensory organs of smell, and trace the olfactory pathways to their destination in the brain. Identify the accessory and internal structures of the eye, and explain their function. Explain how light stimulates the production of nerve impulses, and trace the visual pathways to their destination in the brain. Describe the structures of the external and middle ear and explain how they function.

3. Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Learning Objectives Describe the parts of the inner ear and their roles in equilibrium and hearing. Trace the pathways for the sensations of equilibrium and hearing to their destinations in the brain.

4. Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings SECTION 17-1 Olfaction

5. Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Contain olfactory epithelium with olfactory receptors, supporting cells, basal cells Olfactory receptors are modified neurons Surfaces are coated with secretions from olfactory glands Olfactory reception involved detecting dissolved chemicals as they interact with odorant binding proteins Olfactory organs

6. Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Figure 17.1 The Olfactory Organs Figure 17.1a, b

7. Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Olfactory pathways No synapse in the thalamus for arriving information Olfactory discrimination Can distinguish thousands of chemical stimuli CNS interprets smells by pattern of receptor activity Olfactory receptor population shows considerable turnover Number of receptors declines with age Olfaction

8. Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings SECTION 17-2 Gustation

9. Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Clustered in taste buds Associated with lingual papillae Taste receptors

10. Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Contain basal cells which appear to be stem cells Gustatory cells extend taste hairs through a narrow taste pore Taste buds

11. Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Figure 17.2 Figure 17.2 Gustatory Reception

12. Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Taste buds are monitored by cranial nerves Synapse within the solitary nucleus of the medulla oblongata Then on to the thalamus and the primary sensory cortex Gustatory pathways

13. Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Primary taste sensations Sweet, sour, salty, bitter Receptors also exist for umami and water Taste sensitivity shows significant individual differences, some of which are inherited The number of taste buds declines with age Gustatory discrimination

14. Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings SECTION 17-3 Vision

15. Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Eyelids (palpebrae) separated by the palpebral fissue Eyelashes Tarsal glands Lacrimal apparatus Accessory structures of the eye

16. Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Figure 17.3a, b Figure 17.3 Eternal Features and Accessory Structures of the Eye

17. Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings external structures of the eye Conjunctiva covers most of eye Cornea is transparent anterior portion

18. Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Lacrimal apparatus Secretions from the lacrimal gland contain lysozyme Tears form in the lacrimal glands, wash across the eye and collect in the lacrimal lake Pass through the lacrimal punctae, lacrimal canaliculi, lacrimal sac and nasolacrimal duct

19. Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings The eye Three layers Outer fibrous tunic Sclera, cornea, limbus Middle vascular tunic Iris, ciliary body, choroid Inner nervous tunic Retina

20. Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Figure 17.4a, b Figure 17.4 The Sectional Anatomy of the Eye

21. Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings internal structures of the eye Ciliary body Ciliary muscles and ciliary processes, which attach to suspensory ligaments of lens Retina Outer pigmented portion Inner neural part Rods and cones

22. Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Figure 17.4c Figure 17.4 The Sectional Anatomy of the Eye

23. Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Figure 17.5 Figure 17.5 The Pupillary Muscles