1. Special Senses Part One Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings

3. Temperature

4. Pressure

5. Pain

6. Special senses

7. Smell

8. Taste

9. Sight

10. Hearing

11. EquilibriumSlide 8.1 Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings

13. Each eye has over a million nerve fibers

14. Protection for the eye

15. Most of the eye is enclosed in a bony orbit

16. A cushion of fat surrounds most of the eyeSlide 8.2 Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings

18. EyelashesFigure 8.1b Slide 8.3a Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings

22. Membrane that lines the eyelids

23. Connects to the surface of the eye

24. Secretes mucus to lubricate the eyeSlide 8.4a Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings

26. Lacrimal gland – produces lacrimal fluid

27. Lacrimal canals – drains lacrimal fluid from eyesFigure 8.1a Slide 8.4b Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings

31. Dilute salt solution (tears)

32. Contains antibodies and lysozyme

33. Protects, moistens, and lubricates the eye

34. Empties into the nasal cavitySlide 8.5 Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings

36. Produce eye movementsFigure 8.2 Slide 8.6 Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings

38. Fibrous tunic – outside layer

39. Choroid – middle layer

40. Sensory tunic – inside layerFigure 8.3a Slide 8.7 Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings

42. White connective tissue layer

43. Seen anteriorly as the “white of the eye”

44. Cornea

45. Transparent, central anterior portion

46. Allows for light to pass through

47. Repairs itself easily

48. The only human tissue that can be transplanted without fear of rejectionSlide 8.8 Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings

50. Pigment prevents light from scattering

51. Modified interiorly into two structures

52. Cilliary body – smooth muscle

53. Iris

54. Pigmented layer that gives eye color

55. Pupil – rounded opening in the irisSlide 8.9 Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings

57. Rods

58. Cones

59. Signals pass from photoreceptors via a two-neuron chain

60. Bipolar neurons

61. Ganglion cells

62. Signals leave the retina toward the brain through the optic nerveSlide 8.10 Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings

63. Neurons of the Retina Figure 8.4 Slide 8.11 Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings

65. Most are found towards the edges of the retina

66. Allow dim light vision and peripheral vision

67. Perception is all in gray tonesSlide 8.12a Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings

69. Allow for detailed color vision

70. Densest in the center of the retina

71. Fovea centralis – area of the retina with only cones

72. No photoreceptor cells are at the optic disk, or blind spotSlide 8.12b Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings

74. Different cones are sensitive to different wavelengths

75. Color blindness is the result of lack of one cone typeSlide 8.13 Figure 8.6 Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings

77. Held in place by a suspensory ligament attached to the ciliary bodyFigure 8.3a Slide 8.14 Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings

79. Watery fluid found in chamber between the lens and cornea

80. Similar to blood plasma

81. Helps maintain intraocular pressure

82. Provides nutrients for the lens and cornea

83. Reabsorbed into venous blood through the canal of SchlemmSlide 8.15a Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings

85. Gel-like substance behind the lens

86. Keeps the eye from collapsing

87. Lasts a lifetime and is not replacedSlide 8.15b Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings

89. The eye is set for distance vision (over 20 ft away)

90. The lens must change shape to focus for closer objectsSlide 8.16 Figure 8.9 Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings

91. Images Formed on the Retina Figure 8.10 Slide 8.17 Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings

93. Optic nerve

94. Optic nerve crosses at the optic chiasmaSlide 8.18a Figure 8.11 Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings

96. Thalamus (axons form optic radiation)

97. Visula cortex of the occipital lobeSlide 8.18b Figure 8.11 Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings

99. Bright light causes pupils to constrict through action of radial and ciliary muscles

100. Viewing close objects causes accommodation

101. External muscles control eye movement to follow objects

102. Viewing close objects causes convergence (eyes moving medially)Slide 8.19 Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings