1. 1 ANATOMY & PHYSIOLOGY I BIO 211: Dr. Lawrence G. Altman www.lawrencegaltman.com Some illustrations are courtesy of McGraw-Hill. The EAR Part 1 of 2 SPECIAL SENSES LABS: Dr. Lawrence G. Altman www.lawrencegaltman.com Some illustrations are courtesy of McGraw-Hill.

2. 2

3. 3 3 OSSICLES: AURICLE TYMPANIC MEMBRANE a.k.a the EARDRUM ROUND WINDOW TYMPANICCAVITY AUDITORY TUBE a.k.a. EUSTACHIAN OVAL WINDOW STAPES INCUS MALLEUS equivalent- p. 470

4. 4 TYMPANIC MEMBRANE a.k.a the EARDRUM TYMPANICCAVITY OVAL WINDOW STAPES INCUS

5. 5 COCHLEA SEMICIRCULAR DUCTS VESTIBULE UTRICLE SACCULE

6. 6 VESTIBULAR MEMBRANE TECTORIAL MEMBRANE BASILAR MEMBRANE ORGAN OF CORTI SCALA VESTIBULI COCHLEAR DUCT SCALA TYMPANI

7. 7 TECTORIAL MEMBRANE BASILAR MEMBRANE equivalent- p. 473

8. 8

9. 9

10. 10 Last Plate The EAR (Part 1 of 2) Sequence of events involved in hearing. 1. Sound waves are funneled by the auricle into the external auditory meatus. 2. The sound waves strike the tympanic membrane, causing it to vibrate. 3. Vibrations of the tympanic membrane are amplified as they pass through the malleus, incus, and stapes. 4. The vestibular window (oval window) is pushed back and forth by the stapes. 5. Vibrations of the vestibular window set up pressure waves in the perilymph of the cochlea. 6. The pressure waves area propagated through the scala vestibuli and the scala tympani to the endolymph contained within the cochlear duct. 7. Stimulation of the hair cells within the spiral organ of the cochlea causes the generation of nerve impulses in the cochlear nerve (a portion of the vestibular[eighth cranial] nerve), which pass into the pons of the brain. Theory and Problems of HumanAnatomy & Physiology, K.M.Van De Graaf and R.W. Rhees, McGraw-Hill, 1997