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24 Cards in this Set
- Front
- Back
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What 3 parts make up the OE? |
Pinna External Auditory Meatus Tympanic Membrane |
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What 4 parts make up the peripheral aud system? |
OE ME IE Aud. Nerve |
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Name 3 purposes of the OE |
Protection Absorption of sounds Transformation of acoustic energy into mechanical vibratory energy |
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Where should you look with an otoscope? |
Behind pinna and in EAM |
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Pinna is made of what? |
Consists of several pieces of cartilage which are held together by ligaments. Covered by epidermis. Has vestigial muscles. |
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Vestigal Muscles |
Anterior, Superior, and Posterior. (all auricular). to wiggle ears |
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What is the deep center of pinna? Dimensions? |
Concha. It is 1-2cm in diameter and leads to an opening 5-7mm. |
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What do the series of ridges and depression in the pinna do? |
Complex resonator. Collects and filters sound so that it amplifies high freq. sounds (5k) and attenuates others (low freq). Pinna also increase sound pressure of incoming sounds |
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What is the pinna notch? |
Creates a notch filtering effect due to the waves interacting with each other. |
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Describe interal structure of Pinna? |
Same as external. the cartilage is continuous with the cartilage that forms the EAM. |
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Pinna Landmarks-7/8 |
Helix Anti-helix (splint into 2 segments aka crura) Tragus Anti-tragus Inter-Tragal Notch Concha Triangular Fossa *Scaphoid fossa-groove that runs down the posterior portion of the pinna |
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Dimensions of the EAM (adult) |
2-3 cm in length .75 in diameter |
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Lateral portion of EAM |
1/3-1/2, cartilaginous |
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Medial part of EAM and it's structures |
Bony portion 1) Tympanic portion of temp bone 2) Squamous portion of temp bone 3) Condoyle of mandible |
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What can happen toe the EAM with TMJ? |
It can change shape |
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Why is it important to never push on the EMI? |
It can change EAM shape. |
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EAM is covered in what? |
Skin and hair cells |
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What glands are in the EAM? |
Sebaceous glands & apocrine sweat glands |
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What do sebaceous galnds create? |
Sebum: an odorless combination of fatty acids |
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Where are the sebaceous glands located? |
In the outer third of EAM, (cartilage portion) |
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What is cermun? |
Earwax: combination of sebum and sweat. |
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Purpose of cerumen -3 |
1) lubricates ears 2) insect repellant 3) picks up other substances (dead skin, dust) and draws out of EAM |
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What are the 4 nerves in the EAM? |
V (trigeminal)-biting, chewing VII (facial)-facial paralysis IX (glossopharyngeal)-sensory for pharynx X (vagus)-fainting |
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Function of EAM |
Carries sound through EAM to TM. Is quarter-wave resonator (bc closed on one end) |
