1 / 22

Understanding the Ear: Physiology and Anatomy

Explore the sensory physiology of hearing and equilibrium in the ear. Learn about the divisions of the ear, mechanisms of hearing, and integration processes. Detailed insights on hair cell transduction and issues like deafness are discussed.

lglenda
Download Presentation

Understanding the Ear: Physiology and Anatomy

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Sensory Physiology_hearing

  2. The Ear • Houses two senses • Hearing • Equilibrium (balance) • Receptors are mechanoreceptors

  3. Hearing: Mechanoreceptors • Sound waves • Conduction • Air • Bone • Fluid • Membranes • To hair cell

  4. Anatomy of the Ear • The ear is divided into three areas • Outer (external) ear • Middle ear • Inner ear Figure 8.12

  5. The External Ear • Involved in hearing only • Structures of the external ear • Pinna • External auditory canal Figure 8.12

  6. The External Auditory Canal • Narrow chamber in the temporal bone • Lined with skin • wax glands are present • Ends at the tympanic membrane

  7. The Middle Ear or Tympanic Cavity • Air-filled cavity within the temporal bone • Only involved in the sense of hearing

  8. The Middle Ear or Tympanic Cavity • Two tubes are associated with the inner ear • The opening from the auditory canal is covered by the tympanic membrane • The auditory tube connecting the middle ear with the throat • Allows for equalizing pressure during yawning or swallowing • This tube is otherwise collapsed

  9. Bones of the Tympanic Cavity • Three bones span the cavity • Malleus (hammer) • Incus (anvil) • Stapes (stirrip) Figure 8.12

  10. Bones of the Tympanic Cavity • Vibrations from eardrum move the malleus • These bones transfer sound to the inner ear Figure 8.12

  11. Inner Ear or Bony Labyrinth • Includes sense organs for hearing and balance • Filled with perilymph Figure 8.12

  12. Inner Ear or Bony Labyrinth • A maze of bony chambers within the temporal bone • Cochlea • Vestibule • Semicircular canals Figure 8.12

  13. Hearing: Mechanoreceptors Figure 10-19: Sound transmission through the ear

  14. Mechanisms of Hearing Figure 8.14 Slide 8.29

  15. Hearing: Hair Cell Transduction Figure 10-20: The cochlea

  16. Organs of Hearing • Organ of Corti • Located within the cochlea • Receptors = hair cells on the basilar membrane • Gel-like tectorial membrane is capable of bending hair cells • Cochlear nerve attached to hair cells transmits nerve impulses to auditory cortex on temporal lobe Slide 8.27a

  17. Organs of Hearing Figure 8.13 Slide 8.27b

  18. Mechanisms of Hearing • Vibrations from sound waves move tectorial membrane • Hair cells are bent by the membrane • An action potential starts in the cochlear nerve • Continued stimulation can lead to adaptation Slide 8.28

  19. Hearing: Hair Cell Transduction • Fluid wave moves • Tectoral membrane • Steriocilia move • Ion channels open • Depolarization • NT release • Sensory nerve AP

  20. Hearing: Hair Cell Transduction Figure 10-21: Signal transduction in hair cells

  21. Hearing: Integration and Problems • Pitch • Intensity • Localization • Integration • Thalamus • Auditory cortex • Deafness • Conductive • Sensory / neural Figure 10-5: Localization of sound

  22. Hearing: Integration and Problems Figure 10-22: Sensory coding for pitch

More Related