1. Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Figure 17.6b, c Figure 17.6 The Organization of the Retina

2. Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Ciliary body and lens divide the anterior cavity of the eye into posterior (vitreous) cavity and anterior cavity Anterior cavity further divided anterior chamber in front of eye posterior chamber between the iris and the lens Eye anatomy

3. Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Figure 17.8 Figure 17.8 The Circulation of Aqueous Humor

4. Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Aqueous humor circulates within the eye diffuses through the walls of anterior chamber passes through canal of Schlemm re-enters circulation Vitreous humor fills the posterior cavity. Not recycled – permanent fluid Fluids in the eye

5. Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Posterior to the cornea and forms anterior boundary of posterior cavity Posterior cavity contains vitreous humor Lens helps focus Light is refracted as it passes through lens Accommodation is the process by which the lens adjusts to focus images Normal visual acuity is 20/20 Lens

6. Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Figure 17.9 Figure 17.9 Image Formation

7. Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Figure 17.10 Figure 17.10 Accommodation

8. Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Figure 17.11 Figure 17.11 Visual Abnormalities

9. Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Rods – respond to almost any photon Cones – specific ranges of specificity Visual physiology

10. Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Figure 17.13 Figure 17.13 Rods and Cones

11. Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Outer segment with membranous discs Narrow stalk connecting outer segment to inner segment Light absorption occurs in the visual pigments Derivatives of rhodopsin Photoreceptor structure

12. Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Figure 17.14 Photoreception Animation: Photoreception PLAY Figure 17.14a, b

13. Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Figure 17.14 Photoreception Figure 17.14c, d

14. Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Figure 17.15 Figure 17.15 Bleaching and Regeneration of Visual Pigments

15. Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Integration of information from red, blue and green cones Colorblindness is the inability to detect certain colors Color sensitivity

16. Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Dark adapted – most visual pigments are fully receptive to stimulation Light adapted – pupil constricts and pigments bleached. retinal adaptation

17. Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Large M-cells monitor rods Smaller more numerous P cells monitor cones the visual pathway

18. Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Figure 17.18 Figure 17.18 Convergence and Ganglion Cell Function

19. Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Vision from the field of view transfers from one side to the other while in transit Depth perception is obtained by comparing relative positions of objects from the two eyes Seeing in stereo

20. Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Figure 17.19 Figure 17.19 The Visual Pathways

21. Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Input to suprachiasmic nucleus affects the function of the brainstem Circadian rhythm ties to day-night cycle, and affects metabolic rates Visual circadian rhythm

22. Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings SECTION 17-4 Equilibrium and Hearing

23. Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Anatomy of the ear – External Ear Auricle or pinnae surrounds the ear External acoustic meatus ends on tympanic membrane Both equilibrium and hearing are provided by receptors of the inner ear

24. Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Figure 17.20 Figure 17.20 The Anatomy of the Ear

25. Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Communicates with pharynx via pharyngotympanic membrane Middle ear encloses and protects the auditory ossicles Middle ear

26. Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Figure 17.21 Figure 17.21 The Middle Ear

27. Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Membranous labyrinth contains endolymph Bony labyrinth surrounds and protects membranous labyrinth Vestibule Semicircular canals Cochlea Inner ear

28. Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Figure 17.22 Figure 17.22 The Inner Ear

29. Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Vestibule contains the utricle and saccule Semicircular canals contain the semicircular ducts Cochlea contains the cochlear duct Components of the inner ear

30. Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Round window separates the perilymph from the air spaces of the middle ear Oval window connected to the base of the stapes Basic receptors of inner ear are hair cells Provide information about the direction and strength of stimuli Windows

31. Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Anterior, posterior and lateral semicircular ducts are continuous with the utricle Each duct contains an ampulla with a gelatinous cupula and associated sensory receptor Saccule and utricle connected by a passageway continuous with the endolymphatic duct Terminates in the endolymphatic sac Saccule and utricle have hair cells clustered in maculae Cilia contact the otolith (statoconia) Equilibrium

32. Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Figure 17.23a, b, & d Figure 17.23 The Vestibular Complex

33. Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Figure 17.23c Figure 17.23 The Vestibular Complex

34. Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Figure 17.23e Figure 17.23 The Vestibular Complex

35. Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Vestibular receptors activate sensory neurons of the vestibular ganglia Axons form the vestibular branch of cranial nerve VII Synapses within the vestibular nuclei Vestibular neural pathway

36. Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Figure 17.24 Figure 17.24 Pathways for Equilibrium Sensation

37. Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Cochlear duct lies between the vestibular duct and the tympanic duct Hair cells of the cochlear duct lie within the Organ of Corti Intensity is the energy content of a sound Measured in decibels Hearing

38. Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Figure 17.25a, b Figure 17.25 The Cochlea

39. Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Figure 17.26a, b Figure 17.26 The Organ Of Corti

40. Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Sound waves travel toward tympanic membrane, which vibrates Auditory ossicles conduct the vibration into the inner ear Tensor tympani and stapedius muscles contract to reduce the amount of movement when loud sounds arrive Movement at the oval window applies pressure to the perilymph of the cochlear duct Pressure waves distort basilar membrane Hair cells of the Organ of Corti are pushed against the tectoral membrane Pathway of sound

41. Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Figure 17.28a Figure 17.28 Sound and Hearing

42. Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Figure 17.29 Figure 17.29 Sound and Hearing

43. Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Neural pathway Sensory neurons of hearing are located in the spiral ganglion of the cochlea Afferent fibers form the cochlear branch of cranial nerve VIII Synapse at the cochlear nucleus

44. Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings You should now be familiar with: The sensory organs of smell, and the olfactory pathways in the brain. The accessory and internal structures of the eye, and their functions. How light stimulates the production of nerve impulses, and the visual pathways. The structures of the external and middle ear and how they function. The parts of the inner ear and their roles in equilibrium and hearing. The pathways for the sensations of equilibrium and hearing.