Ch09 lecture ppt_a (1)
- 1. Seeley’s ESSENTIALS OF Anatomy & Physiology Tenth Edition Cinnamon Vanputte Jennifer Regan Andrew Russo See separate PowerPoint slides for all figures and tables pre-inserted into PowerPoint without notes. © 2019 McGraw-Hill Education. All rights reserved. Authorized only for instructor use in the classroom. No reproduction or further distribution permitted without the prior written consent of McGraw-Hill Education.
- 2. © 2019 McGraw-Hill Education 2 Chapter 9 Senses Lecture Outline
- 3. © 2019 McGraw-Hill Education 3 Senses Are the means by which the brain receives information about the environment and the body. Sensation The process initiated by stimulating sensory receptors. PERCEPTION conscious awareness of stimuli received by sensory neurons
- 4. © 2019 McGraw-Hill Education 4 Characteristic of Sensation PROJECTION The sensation seems to come from the area where the receptors were stimulated, even though it is the brain that truly feels the sensation INTENSITY The degree to which the sensation is felt; a strong stimulus affects more receptors and more impulses are sent to the brain
- 5. © 2019 McGraw-Hill Education 5 Characteristic of Sensation CONTRAST The effect of a previous or simultaneous sensation on a current sensation as the brain compares them. ADAPTATION Becoming aware of continuing stimulus If the stimulus remains constant, there is no change for the receptors to detect.
- 6. © 2019 McGraw-Hill Education 6 Characteristic of Sensation AFTER IMAGE The sensation remains in the consciousness after the stimulus has stopped.
- 7. © 2019 McGraw-Hill Education 7 Classification of Senses Figure 9.1
- 8. © 2019 McGraw-Hill Education 8 Types of Senses General senses • receptors over large part of body that sense touch, pressure, pain, temperature, and itch • somatic provide information about body and environment • visceral provide information about internal organs Special senses • smell, taste, sight, hearing, and balance
- 9. © 2019 McGraw-Hill Education 9 Sensory receptors are sensory nerve endings or specialized cells respond to stimuli by developing action potentials
- 10. © 2019 McGraw-Hill Education 10 Types of Receptors1 Mechanoreceptors: • detect movement • Example, touch, pressure, vibration Chemoreceptors: • detect chemicals • Example, Odors Photoreceptors: • detect light
- 11. © 2019 McGraw-Hill Education 11 Types of Receptors2 Thermoreceptors: • detect temp. changes Nociceptors: • detect pain
- 12. © 2019 McGraw-Hill Education 12 Types of Touch Receptors1 Merkel’s disk: • detect light touch and pressure Hair follicle receptors: • detect light touch Meissner corpuscle: • deep in epidermis • localizing tactile sensations
- 13. © 2019 McGraw-Hill Education 13 Types of Touch Receptors2 Ruffini corpuscle deep tactile receptors detects continuous pressure in skin Pacinian corpuscle deepest receptors associated with tendons and joints detect deep pressure, vibration, position
- 14. © 2019 McGraw-Hill Education 14 Sensory Receptors in the Skin Figure 9.2
- 15. © 2019 McGraw-Hill Education 15 Pain an unpleasant perceptual and emotional experience can be localized or diffuse. Localized sharp, pricking, cutting pain rapid action potential Diffuse burning, aching pain slower action potentials
- 16. © 2019 McGraw-Hill Education 16 Pain Control Local anesthesia: • action potentials suppressed from pain receptors in local areas of the body • chemicals are injected near sensory nerve General anesthesia: • loss of consciousness • chemicals affect reticular formation
- 17. © 2019 McGraw-Hill Education 17 Referred Pain A visceral pain that is felt as a cutaneous pain originates in a region that is not source of pain stimulus felt when internal organs are damaged or inflamed sensory neurons from superficial area and neurons of source pain converge onto same ascending neurons of spinal cord
- 18. © 2019 McGraw-Hill Education 18 Areas of Referred Pain Figure 9.3
- 19. © 2019 McGraw-Hill Education 19 Olfaction Olfaction • sense of smell • occurs in response to odorants • receptors are located in nasal cavity and hard palate • we can detected 10,000 different smells Figure 9.4a
- 20. © 2019 McGraw-Hill Education 20 Olfaction Process 1. Nasal cavity contains a thin film of mucous where odors become dissolved. 2. Olfactory neurons are located in mucous. Dendrites of olfactory neurons are enlarged and contain cilia. 3. Dendrites pick up odor, depolarize, and carry odor to axons in olfactory bulb (cranial nerve I). 4. Frontal and temporal lobes process odor.
- 21. © 2019 McGraw-Hill Education 21 Olfactory Epithelium and Olfactory Bulb Figure 9.4b
- 22. © 2019 McGraw-Hill Education 22 Taste Taste buds sensory structures that detect taste located on papillae on tongue, hard palate, throat Inside each taste bud are 40 taste cells Each taste cell has taste hairs that extend into taste pores
- 23. © 2019 McGraw-Hill Education 23 The Tongue Figure 9.5
- 24. © 2019 McGraw-Hill Education 24 Taste Process 1. Taste buds pick up taste and send it to taste cells. 2. Taste cells send taste to taste hairs. 3. Taste hairs contain receptors that initiate an action potential which is carried to parietal lobe. 4. Brain processes taste.
- 25. © 2019 McGraw-Hill Education 25 Types of Tastes 1. Sweet 2. Sour 3. Salty 4. Bitter 5. Umami/savory
- 26. © 2019 McGraw-Hill Education 26 Pathways for the Sense of Taste Figure 9.6
- 27. © 2019 McGraw-Hill Education 27 Vision Accessory Structures Eyebrow: protects from sweat shade from sun Eyelid/Eyelashes: protects from foreign objects lubricates by blinking
- 28. © 2019 McGraw-Hill Education 28 The Eye and Accessory Structures1 Figure 6.7a (a) ©Eric Wise
- 29. © 2019 McGraw-Hill Education 29 The Eye and Accessory Structures2 Conjunctiva thin membrane that covers inner surface of eyelid Lacrimal Gland produces tears Extrinsic eye muscles help move eyeball
- 30. © 2019 McGraw-Hill Education 30 Lacrimal Gland Structures Figure 9.7c
- 31. © 2019 McGraw-Hill Education 31 Extrinsic Eye Muscles Figure 9.8
- 32. © 2019 McGraw-Hill Education 32 Anatomy of Eye Hollow, fluid filled sphere Composed of 3 layers (tunics) Divided into chambers
- 33. © 2019 McGraw-Hill Education 33 The Eye Figure 9.9
- 34. © 2019 McGraw-Hill Education 34 LAYERS OF THE EYE 1. Fibrous Tunic layer Outermost Tunic Sclera: • firm, white outer part • helps maintain eye shape, provides attachment sites, protects internal structures Cornea: • transparent structure that covers iris and pupil • allows light to enter and focuses light
- 35. © 2019 McGraw-Hill Education 35 2. Vascular Tunic Middle tunic that contains blood supply Choroid- black part (melanin), delivers O2 and nutrients to retina Ciliary body helps hold lens in place Suspensory ligaments help to hold lens in place
- 36. © 2019 McGraw-Hill Education 36 Vascular Tunic2 Lens flexible disk focuses light onto retina Iris colored part surrounds and regulates pupil
- 37. © 2019 McGraw-Hill Education 37 Vascular Tunic3 Pupil regulates amount of light entering lots of light = constricted little light = dilated
- 38. © 2019 McGraw-Hill Education 38 Lens and Ciliary Body Figure 9.10
- 39. © 2019 McGraw-Hill Education 39 The Iris Figure 9.11
- 40. © 2019 McGraw-Hill Education 40 3. Nervous Tunic1 Innermost tunic and consist of retina. Retina covers posterior 5/6 of eye contains 2 layers Pigmented retina outer layer keeps light from reflecting back in eye
- 41. © 2019 McGraw-Hill Education 41 Nervous Tunic2 Sensory retina contains photoreceptors (Rods and Cones) contains interneurons
- 42. © 2019 McGraw-Hill Education 42 Rods photoreceptor sensitive to light 20 times more rods than cones can function in dim light Cones photoreceptor provide color vision 3 types blue, green, red
- 43. © 2019 McGraw-Hill Education 43 Pigments and Pigment Protein Rhodopsin: • photosensitive pigment in rod cells Opsin: • colorless protein in rhodopsin Retinal: • yellow pigment in rhodopsin • requires vitamin A
- 44. © 2019 McGraw-Hill Education 44 Effects of Light on Rhodopsin1 1. Light strikes rod cell 2. Retinal changes shape 3. Opsin changes shape 4. Retinal dissociates from opsin 5. Change rhodopsin shape stimulates response in rod cell which results in vision 6. Retinal detaches from opsin 7. ATP required to reattach retinal to opsin and return rhodopsin to original shape
- 45. © 2019 McGraw-Hill Education 45 Effects of Light on Rhodopsin2 Figure 9.13
- 46. © 2019 McGraw-Hill Education 46 Posterior Region of Retina3 Macula • small spot near center of retina Fovea centralis Center of macula The light is focused when looking directly at an object Cnly cones Ability to discriminate fine images
- 47. © 2019 McGraw-Hill Education 47 Posterior Region of Retina 3 Optic disk white spot medial to macula blood vessels enter eye and spread over retina no photoreceptors called blind spot
- 48. © 2019 McGraw-Hill Education 48 The Retina5 Figure 9.14
- 49. © 2019 McGraw-Hill Education 49 Chambers of the Eye1 Anterior chamber located between cornea and lens filled with Aqueous Humor (watery) Aqueous humor helps maintain pressure, refracts light, and provide nutrients to inner surface of eye Posterior chamber located behind anterior chamber contains aqueous humor
- 50. © 2019 McGraw-Hill Education 50 Chambers of the Eye2 Vitreous chamber located in retina region filled with vitreous humor: jelly-like substance vitreous humor helps maintain pressure, holds lens and retina in place, refracts light
- 51. © 2019 McGraw-Hill Education 51 Functions of the Eye The eye functions much like a camera. The iris allows light into the eye, which is focused by the cornea, lens, and humors onto the retina. The light striking the retina produces action potentials that are relayed to the brain. Light refraction and image focusing are two important processes in establishing vision.
- 52. © 2019 McGraw-Hill Education 52 Functions of the Eye2 Light Refraction • Bending of light Focal point: • point where light rays converge • occurs anterior to retina • object is inverted
- 53. © 2019 McGraw-Hill Education 53 Focusing by the Eye Figure 9.15
- 54. © 2019 McGraw-Hill Education 54 Focusing Images on Retina Accommodation Lens becomes less rounded and image can be focused on retina Enables eye to focus on images closer than 20 feet
- 55. © 2019 McGraw-Hill Education 55 Focusing by the Eye Figure 9.15
- 56. © 2019 McGraw-Hill Education 56 Visual Defects1 Myopia nearsightedness image is in front of retina Hyperopia farsightedness image is behind retina
- 57. © 2019 McGraw-Hill Education 57 Presbyopia: lens becomes less elastic reading glasses required
- 58. © 2019 McGraw-Hill Education 58 Visual Defects Diplopia AKA Double vision Misalignment of the two eyes Due to weakness of the muscles
- 59. © 2019 McGraw-Hill Education 59 Visual Defects2 Astigmatism irregular curvature of lens or cornea glasses or contacts required to correct Color Blindness absence or deficient cones primarily in males
- 60. © 2019 McGraw-Hill Education 60 Glaucoma increased pressure in eye can lead to blindness
- 61. © 2019 McGraw-Hill Education 61 Visual Defects CATARACT Clouding or opacity of crystalline lens that leads to blurring of vision and eventually loss of sight
- 62. © 2019 McGraw-Hill Education 62 Chart to Determine Color Blindness Figure 6.16 (a) ©Steve Allen/Getty Images RF; (b) ©Prisma Bildagentur AG/Alamy
- 63. © 2019 McGraw-Hill Education 63 The Ear The organs of hearing and balance are located in the ears. Each ear is divided into three areas: 1. the external ear 2. the middle ear 3. the inner ear
- 64. © 2019 McGraw-Hill Education 64 The External Ear Auricle/Pinna fleshy part on outside External auditory meatus canal that leads to eardrum Tympanic membrane Eardrum thin membrane that separates external from the middle ear Sound waves reaching the TM cause it to vibrate
- 65. © 2019 McGraw-Hill Education 65 Structure of the Ear Figure 9.18
- 66. © 2019 McGraw-Hill Education 66 Middle Ear Air filled chamber with ossicles Malleus (hammer) bone attached to tympanic membrane Incus (anvil) bone that connects malleus to stapes Stapes (stirrup) bone located at base of oval window
- 67. © 2019 McGraw-Hill Education 67 The Middle Ear2 Oval window: • separates middle and inner ear Eustachian or auditory tube: • opens into pharynx • equalizes air pressure between outside air and middle ear
- 68. © 2019 McGraw-Hill Education 68 Inner Ear Set of fluid filled chambers Bony labyrinth tunnels filled with fluid 3 regions: cochlea, vestibule, semicircular canals Membranous labyrinth inside bony labyrinth filled with endolymph
- 69. © 2019 McGraw-Hill Education 69 The Inner Ear2 Endolymph: • clear fluid in membranous labyrinth Perilymph: • fluid between membranous and bony labyrinth
- 70. © 2019 McGraw-Hill Education 70 Cochlea • snail-shell shaped structure • where hearing takes place • Has three channels
- 71. © 2019 McGraw-Hill Education 71 Channels of Cochlea Scala vestibuli • Extends from the oval window to the apex of cochlea; filled with perilymph Scala tympani • Extend in parallel; filled with perilymph Cochlea duct • Formed by the space between vestibular and basilar membrane; filled with endolymph
- 72. © 2019 McGraw-Hill Education 72 The Inner Ear5 Vestibular membrane wall of membranous labyrinth that lines scala vestibuli Basilar membrane wall of membranous labyrinth that lines scala tympani
- 73. © 2019 McGraw-Hill Education 73 The Inner Ear4 Spiral organ/Organ of Corti • in cochlear duct • contains hair cells Tectorial membrane: • in cochlea • vibrates against hair cells
- 74. © 2019 McGraw-Hill Education 74 Structure of the Ear Figure 9.18
- 75. © 2019 McGraw-Hill Education 75 Structure of the Inner Ear Figure 6.19 (e) Courtesy of A. J. Hudspeth
- 76. © 2019 McGraw-Hill Education 76 Effect of Sound Waves on Middle and Inner Ear Structures Figure 9.20
- 77. © 2019 McGraw-Hill Education 77 Balance (Equilibrium) Static equilibrium associated with vestibule evaluates position of head relative to gravity Dynamic equilibrium associated with semicircular canals evaluates changes in direction and rate of head movement
- 78. © 2019 McGraw-Hill Education 78 Balance1 Vestibule: • inner ear • contains utricle and saccule Maculae: • specialized patches of epithelium in utricle and saccule surround by endolymph • contain hair cells
- 79. © 2019 McGraw-Hill Education 79 Balance2 Otoliths: • gelatinous substance that moves in response to gravity • attached to hair cell microvilli which initiate action potentials
- 80. © 2019 McGraw-Hill Education 80 Location and Structure of the Macula Figure 6.22 (d) ©Susumu Nishinag/Science Source
- 81. © 2019 McGraw-Hill Education 81 Function of the Vestibule in Maintaining Balance Figure 6.23 (d) ©Susumu Nishinag/Science Source
- 82. © 2019 McGraw-Hill Education 82 Balance3 Semicircular canals: • dynamic equilibrium • sense movement if any direction Ampulla: • base of semicircular canal Crista ampullaris: • in ampulla
- 83. © 2019 McGraw-Hill Education 83 Balance4 Cupula: • gelatinous mass • contains microvilli • float that is displaced by endolymph movement
- 84. © 2019 McGraw-Hill Education 84 Semicircular Canals Figure 6.24
- 85. © 2019 McGraw-Hill Education 85 Function of the Crista Ampullaris Figure 6.25 (a) ©Julie Jacobson/AP Photo