SPHS-S 201 Lecture Notes - Lecture 3: Earwax, Middle Ear, Timpani
29 Jul 2018
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Document Summary
Overview of the peripheral auditory system: sections: external, middle, and inner ears, pinna, also called the auricle. 4000 hz range: outer one-third of the canal is cartilage. Includes the portion of the ear that we see the pinna/auricle, the ear canal and tympanic membrane: middle ear. Includes the ossicles, muscles, and multiple ligaments: can be divided into two, tympanic cavity, lies medially to the tm, contains majority of the me bones of the middle ear, the epitympanic recess. Cone of light: the cone of light, or light reflex, shining light on the tympanic membrane causes a cone-shaped reflection of light to. Tympanic membrane perforations: occurs frequently, common causes for tympanic membrane perforations: Infection: trauma, penetrating wounds, barotrauma, perforations may heal spontaneously, but depends largely on the size of the perforation and the presence of infection. Is critical part of acoustic reflex: tensor tympani, contraction stiffens ossicular chain, reduces range of movement of the tympanic membrane.
