1. Copyright © 2015. F.A. Davis Company Sense Organs Chapter 11

2. Copyright © 2015. F.A. Davis Company Sensory Receptors Some combine with muscle and tissue to form sense organs Most consist of specialized nerve cells or nerve endings

3. Copyright © 2015. F.A. Davis Company Sensory Receptors (cont’d) Sensory receptors transmit information about –Type –Type of stimulus –Location –Location of stimulus –Intensity –Intensity of stimulus

4. Copyright © 2015. F.A. Davis Company Classification of Receptors Chemoreceptors Mechanoreceptors Thermoreceptors Nociceptors Photoreceptors Proprioceptors

5. Copyright © 2015. F.A. Davis Company Question Nociceptors respond to: A.various chemicals inside and outside the body. B.pressure, stretch, or vibration. C.pain from tissue damage. D.changes in temperature.

6. Copyright © 2015. F.A. Davis Company Answer Correct answer: C Rationale: Chemoreceptors react to chemicals. Mechanoreceptors respond to factors that change the position of a receptor (such as pressure, stretch, or vibration) Thermoreceptors respond to changes in temperature.

7. Copyright © 2015. F.A. Davis Company General Senses Include pain, pressure, touch, stretch, and temperature Involve receptors widely distributed in skin, muscles, tendons, joints, and viscera

8. Copyright © 2015. F.A. Davis Company Pain Nociceptors consist of free nerve endings that carry impulses to the brain. Receptors are abundant in skin and mucous membranes; found in almost every organ. Nociceptors use fast and slow pain fibers.

9. Copyright © 2015. F.A. Davis Company Pain Pathway View animation on “Pain pathway”1 2 3 4 5 6

10. Copyright © 2015. F.A. Davis Company Referred Pain

11. Copyright © 2015. F.A. Davis Company Question The true source of pain can be difficult to identify because: A.nociceptors can be stimulated by a variety of chemicals. B.deep body organs do not contain pain fibers. C.some pain signals travel to the thalamus, whereas others travel to the limbic system. D.sensory impulses from different areas often travel to the brain over the same pathway.

12. Copyright © 2015. F.A. Davis Company Answer Correct answer: D Rationale: The different chemicals released by injured receptors have nothing to do with identifying the source of pain. Deep body organs contain slow pain fibers. Pain signals that travel to the thalamus proceed to the postcentral gyrus, making the individual aware of pain; signals that travel to the limbic system trigger emotional responses to pain.

13. Copyright © 2015. F.A. Davis Company Special Senses Include taste, smell, hearing, equilibrium, and vision Involve receptors grouped together or clustered in specialized organs

14. Copyright © 2015. F.A. Davis Company Taste Fungiform papillae Filiform papillae Foliate papillae Vallate papillae Taste buds

15. Copyright © 2015. F.A. Davis Company Smell 1 2 3 4

16. Hearing Auricle Auditory canal

17. Copyright © 2015. F.A. Davis Company Middle Ear Malleus Incus Stapes Tympanic membrane Eustachian tube

18. Copyright © 2015. F.A. Davis Company Inner Ear Semicircular canals Vestibule Cochlea Cochlear duct

19. Copyright © 2015. F.A. Davis Company Inner Ear (cont’d) Basilar membrane Organ of Corti

20. Copyright © 2015. F.A. Davis Company Question Which inner ear structure contains the structures for hearing? A.Vestibule B.Semicircular canals C.Cochlea D.Auricle

21. Copyright © 2015. F.A. Davis Company Answer Correct answer: C Rationale: The vestibule contains organs necessary for the sense of balance. The semicircular canals are crucial for balance and equilibrium. The auricle (pinna) is the visible part of the external ear.

22. Copyright © 2015. F.A. Davis Company How Hearing Occurs View animation on “How hearing occurs”1 2 3 4 5

23. Copyright © 2015. F.A. Davis Company Balance Fluid-filled semicircular canals

24. Copyright © 2015. F.A. Davis Company Inside the Ampulla

25. Copyright © 2015. F.A. Davis Company Dynamic Equilibrium

26. Copyright © 2015. F.A. Davis Company Static Equilibrium

27. Copyright © 2015. F.A. Davis Company Question The utricle and saccule reside inside the: A.vestibule. B.ampulla. C.organ of Corti. D.cochlea.

28. Copyright © 2015. F.A. Davis Company Answer Correct answer: A Rationale: The cupula resides in the ampulla. The cochlea contains the organ of Corti, the hearing sense organ.

29. Copyright © 2015. F.A. Davis Company Vision Eyelashes Conjunctiva Eyebrow Upper eyelid Palpebral fissure Lower eyelidTarsal glands

30. Copyright © 2015. F.A. Davis Company Lacrimal Apparatus Lacrimal punctum Lacrimal gland Nasolacrimal duct Lacrimal canal

31. Copyright © 2015. F.A. Davis Company Extrinsic Eye Muscles Rotate eye to slide and downward Move eye up, down, medially, and laterally

32. Copyright © 2015. F.A. Davis Company Tissue Layers of the Eye Sclera Cornea Iris Ciliary body Choroid Optic nerve Retina

33. Copyright © 2015. F.A. Davis Company Retina Macula lutea Fovea centralis Optic disc

34. Copyright © 2015. F.A. Davis Company Question The outermost layer of the eye is the: A.sclera. B.ciliary body. C.choroid. D.retina.

35. Copyright © 2015. F.A. Davis Company Answer Correct answer: A Rationale: The ciliary body and choroid are parts of the middle vascular layer. The retina is part of the inner neural layer.

36. Copyright © 2015. F.A. Davis Company Eye Chambers and Fluids Anterior cavity Lens Ciliary body Posterior cavity

37. Copyright © 2015. F.A. Davis Company Process of Vision 1.Light focuses on the retina and produces an upside-down image. 2.Rods and cone convert the image to nerve impulses. 3.Impulses are transmitted to the brain.

38. Copyright © 2015. F.A. Davis Company Refraction

39. Constriction of the Pupil Pupillary constrictor Pupillary dilator

40. Copyright © 2015. F.A. Davis Company Accommodation of the Lens

41. Copyright © 2015. F.A. Davis Company Action of Photoreceptors Rods Concentrated at the periphery of the retina Active in dim light Responsible for night vision Cannot distinguish colors from each other Cones Concentrated in the center of the retina Active in bright light Responsible for sharp vision Responsible for color vision

42. Copyright © 2015. F.A. Davis Company Transmission of Impulses 1 2 3

43. Copyright © 2015. F.A. Davis Company Question The bending of light rays so they focus precisely on the retina is called: A.convergence. B.accommodation. C.constriction. D.refraction.

44. Copyright © 2015. F.A. Davis Company Answer Correct answer: D Rationale: Convergence lines up the visual axis of each eye. Accommodation occurs when the lens changes its curvature. Constriction occurs when the pupil narrows to restrict light entering the eye.