2. Taste Smell Vision Hearing Balance

3. respond to chemicals in an aqueous solution food dissolved in saliva airborne chemicals dissolved in mucous membrane Taste and smell are involved with specific receptor cells called chemoreceptors

4. The Tongue

5. Taste Buds Circumvallate Papilla Filiform papilla Fungiform papilla Connective tissue Tongue epithelium

8. Salty- metallic ions Sweet- sugar Sour- H + Bitter- alkaloid Why are they important? Umami- savory/meaty

9. Dry tongue with a paper towel and place a little sugar on surface. What do you taste?

10. Facial nerve  (afferent) 2/3 anterior portion of tongue Glossophyngeal posterior 1/3 of tongue Vagus nerve- few taste buds on epiglottis an pharynx These afferent fibers synapse in medulla  thalamus  gustatory cortex in parietal lobes and fibers to hypothalamus in limbic system

11. Taste triggers reflex involved in digestion; causes an increase of saliva in mouth (amylase) and gastric juice in stomach acids cause strong salivary reflex bad tasting food causes gagging or reflexive vomiting taste can change over time taste is 80% smell Mouth also contains: Thermoreceptors Mechanoreceptors Nociceptors- sensitive nerve fibers that are aware of painful stimuli

12. Smell not as good as animals; however, some people are wine tasters, perfumers If you smell a particular odor all day, you won’t recognize its presence, you become accustomed, ex. garbage men Old people lose sense of smell- lots of perfume Humans can distinguish 10,000 or so chemicals What we really smell is pain: ex. chili, ammonia, menthol (cold) Specific chemicals cause specific patterns of neurons to fire

13. Figure 15.21a Olfactory tract Olfactory bulb (a) Nasal conchae Route of inhaled air Olfactory epithelium

14. Figure 15.21a Mitral cell (output cell) Olfactory gland Olfactory tract Olfactory epithelium Filaments of olfactory nerve Cribriform plate of ethmoid bone Lamina propria connective tissue Basal cell Supporting cell Dendrite Olfactory cilia Olfactory bulb Glomeruli Axon Olfactory receptor cell Mucus Route of inhaled air containing odor molecules (b)

15. Cortical Regions Associated with Olfactory Information

16. Olfactory auras- prior to epileptic attack May be genetic or a cold (mucus), allergy, zinc deficiency loss of sense of smell Lose sense of smell  lose taste Uncinate- olfactory hallucinations; may be psychological ex. rotting meat smell

17. sclera iris pupil tear drainage canal cornea Medial commisure lateral commisure palpabre Lacrimal caruncle

18. bright lightnormal lightdim light

19. FLOW OF TEARS Lacrimal gland Lacrimal ducts Sup. or inf. lacrimal canal Lacrimal sac Nasolacrimal duct Nasal cavity

20. optic nerve Superior rectus Inferior obliqueLateral rectus Inferior rectus Medial rectus Superior oblique

21. Fibrous tunic- sclera and cornea (outer most layer) Composed of dense avascular connective tissue

22. Vascular tunic- uvea: choroid, cilliary body, iris, pupil (middle layer) Choroid- rich vascular nutritive layer; contains a dark pigment that prevents light scattering within the eye Cilliary body- lens is attached; contains muscles that change the lenses shape Iris- pigmented ring of muscular tissue composed of circular and radial muscles reflex contraction of circular muscle in bright light (small dia of pupil) reflex contraction of radial muscle in dim light (large dia of pupil) Pupil- central hole in iris

23. Sensory tunic- retina (inner most layer) Photoreceptors: rods (dim light, contains pigment rhodopsin) and Cones (color vision, not evenly distributed, concentrated in fovea) Optic disc- blind spot because its where optic nerve leaves the eyeball (no rods or cones) Macula lutea- yellow spot, area of high cone Fovea centralis- in center of macula lutea, contains only cones, area of greatest visual acuity

25. Vitreous humor- behind lens, gel-like substance with fine collagenic fibrils imbedded in as viscous ground substance- binds with water transmits light supports the posterior surface of the lens and holds the neural retina firmly against pigmented layer contributes to intraoccular pressure, helping to counter act the pulling force of the extrinsic eye muscles

26. Aqueous humor- in front of lens, anterior segment, watery fluid Supplies cornea and lens with nutrients Helps to maintain the shape of the eye Produced and renewed every 4 hrs by the cilliary body

28. Lens- transparent biconvex structure, flexible Attached by suspensory ligaments to ciliary body focuses image onto retina changes lens thickness to allow light to be properly focused onto retina

29. Coarse Fixed Focusing Cornea Shape Cornea Shape Accommodation- adjust configuration of Lens Shape Lens Shape Pupil Size Pupil Size

30. refraction

31. Focusing on a Near Object

32. Focusing on a Far Object

33. Emmetropia- normal 20:20 Hyperopia- farsighted Myopia-near sighted Presbyopia- mature eyes Astigmatism 20 ft:20 ft You see Normal vision

34. 20/10 What condition does this person have?

39. Clouding of lens (hardening or thickening causes: diabetes mellitus, smoking, UV damage

42. blind spot macula The Retina

44. light photoreceptive cells Choroid Schlera Ganglion Amacrine Bipolar neuron Horizontal cells

46. photoreceptors Rod cell membrane

49. Binocular vision

51. Geometrical illusions

52. Successive contrast : afterimages... what do you see? fixate the black dot in the center for 60 seconds... … and then look at a the black dot in the right panel !

55. Outer ear- pinna (auricle), lobule, external auditory canal; elastic cartilage External auditory canal has: ceruminous glands- wax secreting glands- protects delicate lining of meatus and helps prevent microorganisms from entering the ear Tympanic membrane- membrane that vibrates in response to sound waves

57. Middle ear- Includes 3 small bones (ossicles)- hammer (mallus), anvil (incus), stirup (stapes) Pharyngeotympanic auditory tube (Eustachian tube)- equalizes pressure; connects middle ear to pharynx. Oval window- found on cochlea; stirrup presses against cochlea Round window- pressure window on cochlea Otis media- inflammation of the middle ear; due to bacteria or allergies, common in children whose auditory tubes are short and horizontal

58. external auditory canal tympanic membrane Auditory tube malleus incus stapes round window oval window

60. Inner ear- bony labyrinth filled with perilymph fluid (similar to CFS) and membranous labyrinth filled with endolymph fluid (similar to K+ rich intracellular fluid); these fluids conduct sound vibrations Bony labyrinth (includes vestibule, semicircular canal, and cochlea) Vestibule- posterior to cochlea and anterior to the semicircular canals Perilymph fluid suspends 2 membranous sacs: utricle and sacule-- they house equilibrium receptors called maculae that respond to the pull of gravity

61. Semicircular canal- contains endolymph fluid; anterior, posterior, and lateral canal; contains equilibrium receptors (ampulla) Cochlea- filled with perilymph fluid Organ of Corti- rests a top basilar membrane; has long row of hair cells

63. Biology 100 Human Biology cochlea saccule utricle semicircular canals vestibulochoclear nerve

67. Properties of sound: Sound travels at 331 m/sec It's a pressure disturbance originating from the vibration Frequency- cycles/sec (hertz); Reflects sound intensity Human hearing- 20 to 20,000 htz  Pitch- different frequency's; high vs low; pure tone is a single frequency  Quality- sound mixture with several frequencies  Intensity- corresponds to amplitude of height; loudness measured in decibels

68. Transmission of sound: Airborne sound  external auditory canal  tympanic membrane  hammer, anvil, stirrup  oval window  vestubularcochlear nerve  cochlear nuclei in medulla  superior olive  up the lateral leminiscus  inferior colliculus  primary auditory cortex in the temporal lobe

70. Scala tympani Cochlear duct Basilar membrane MalleusIncus Auditory ossicles Stapes Oval window Scala vestibuli Helicotrema Cochlear nerve 3 2 1 Round window Tympanic membrane (a) Route of sound waves through the ear

74. Fibers of basilar membrane (b) Different sound frequencies cross the basilar membrane at different locations. Medium-frequency sounds displace the basilar membrane near the middle. Low-frequency sounds displace the basilar membrane near the apex. Base (short, stiff fibers) Frequency (Hz) Apex (long, floppy fibers) Basilar membrane High-frequency sounds displace the basilar membrane near the base.

75. Static Balance – utricle and sacule Dynamic Balance- semicircular canals

77. (semicircular canal)

78. cupula hair cells Endolymph fluid Vestibular nerve fibers (semicircular canal)

80. The effect of gravitational pull on the macula receptor cell in the utricle

82. Hearing loss- due to disease (ex. meningitus), damage, or age related Conduction deafness- prevention or blocking sounds from entering inner ear. Ex. ear wax, ruptured ear drum, middle ear inflammation (otis media), and otosclerosis (hardening of the ossicles of the ear) Sensoneural deafness- damage to the neural structures from any point from the cochlear hair cells to and including the auditory cortical cells Partial or complete deafness, or gradual loss over time

83. Tinnitus- ringing or clicking sound in the absence of auditory stimuli; 1 st symptom of cochlear nerve degeneration may result from inflammation of the inner or middle ear side effect from medicine such as aspirin Symptoms- vertigo, nausea, hearing loss Meniere's Syndrome- labyrinth disorder; effects both semicircular canals and cochlea

84. IDENTIFY

85. Hearing Animation: http://health.howstuffworks.com/adam-200010.htm http://www.youtube.com/watch?v=dyenMluFaUw INQUIRY 1.What type of stimulus triggers a response in nociceptors? 2.Two senses that detect chemical concentrations are____. 3.A person with defective otolith sensory receptors may have difficulty ______. 4.Which eye muscle moves the eye to look medially? 5.Name the three bones in the middle ear. 6.What is the blind spot in the eye called? 7.Where are the highest concentration of cones located?