1. Unit 8: The Senses Amy J. Hilbelink, Ph.D. Tracy Abram, MAIS

2. The Senses

3. Objectives Classify sense organs as special or general. Discuss their functions. Discuss how a stimulus is converted into a sensation. List major senses Describe eye and ear anatomy Describe major visual disorders and hearing impairment

4. Classify sense organs as special or general Special: Eye Taste buds Ear Nose General: Microscopic receptors –Pacinian corpuscles –Meissner’s corpuscles –Muscle spindles

5. What is the difference between special and general sense organs?

6. The differences Special = they have large and complex organs or localized groupings of specialized receptors like taste buds on tongue. These are the senses that you typically think of; except for perhaps touch!

7. A very special sense

8. The differences General = made of microscopic receptors widely distributed throughout the body. –Pacinian corpuscles = pressure and high frequency –Meissner’s corpuscles = fine touch and low frequency –Muscle spindles = propriocetors (muscle length and location)

10. Sense organ functions Vision Hearing Smell Taste Balance

11. How is a stimulus converted into a sensation? Stimulus detected [sound] Stimulus converted to electrical signal or nerve impulse= [middle ear] Signal transmitted over nervous system “pathway” = [VIII cranial nerve] Sensation perceived in brain = [music]

12. music

13. Eye anatomy Sclera Choroid Retina Iris Conjunctiva Lacrimal gland Pupil lens

16. My Eye Exam 2011 Prof. Abram’s Left EyeProf. Abram’s Right Eye

17. Prof. Abram OTC Scan

19. Eye anatomy Sclera = white of the eye (cornea) Choroid = contains a dark pigment to prevent scattering of light rays Retina = innermost layer of eyeball (rods and comes) Iris = circular colored part of eye Conjunctiva = mucous membrane that lines eyelids and covers the sclera Lacrimal gland = tear duct Pupil = black center of iris; a hole Lens = ciliary muscles contract the lens for focusing

20. Ear anatomy External ear –External auditory canal –Tympanic membrane –eardrum

24. Ear anatomy Middle ear –Ear bones = ossicles Malleus Incus stapes –Auditory or Eustachian tube

26. Ear anatomy Inner ear –Bony labrinth –Perilymph –Vestibule –Semicircular canals –Cochlea –Crista ampullaris –Organ of Corti

28. Major visual disorders Refraction disorders –Myopia = nearsightedness Astigmatism = irregularity in cornea or lens Conjunctivitis = pink eye Strabismus = convergent

30. Hearing impairment Blockage of external auditory canal Otosclerosis = structural irregularities in stapes Tinnitus = ringing in ears (may be symptom of otosclerosis) Otitis = ear infection Meniere’s disease = chronic inner ear disease, resulting in vertigo

31. Which one would be the worst to lose?

32. Have you any questions? Do you have any questions? Are there any questions? Can I answer anything? Can I answer anything for anybody? Is anything unclear? Is everything clear?