Auditory System

The auditory mechanism is encased within the:

Temporal bone

The auditory mechanism can be broken up into how many parts?

3

Which of the following is NOT a role of the EAM?

Removal of dead tissue towards the tympanic membrane

The outer ear pinna (concha) collects _____ and directs toward the EAM (external auditory meatus)

sound waves

The peripheral auditory anatomy consists of:

outer, middle, and inner ear

The ear canal runs slightly _____.

uphill

Primary role of external auditory meatus

conduct sound energy and removes dead tissue away from the tympanic membrane

Eardrum

boundary b/t outer and middle ear

Annulus

cartilage ligamentous ring linked to bony foundation

Tympanic membrane role

Protects outer ear from middle ear and transforms sound energy from the medium of air to the medium of fluid

Tympanic membrane is composed of 3-layer sheet of tissue

thin epithelial tissue, differently cell structured epithelial tissue, and middle layer

Middle ear chambers include:

ossicles, ligaments, 2 muscles, nerves and eustachian tube

Middle ear cavity parts include

upper chamber, middle, and lower

Middle ear ossicles are the ____ bone in the body

smallest

The 3 smallest bones in the body are

Malleus, Incus, and Stapes

This muscle contracts in response to intense sound and tightens the ossicular chain during the auditory reflex

Tensor Tympani muscle

The stapedius muscle comprises muscular component of ________

acoustic reflex

Auditory (Eustachian) Tube

connects air in middle ear cavity to air in the nasopharynx for pressure control and mucosal clearance

This sensorineural mechanism encases semicircular canals, ampullae, vestibule, and cochlea

Bony labyrinth

Head motion is coded by fluid displacement of hair cells in _____.

ampullae

Head position is coded by fluid displacement of hair cells in ______.

saccule and utricle

Audition is coded by fluid displacement of hair cells within ______

cochlear ducts

The ____ has a basal, middle, and apical turn, each w/3 scala (ducts)

cochlea

_____ receive efferent innervation from brainstem structures

outer hair cells

Outer hair cells enhance frequency analysis of inner hair cells and increase their sensitivity to ______

low-energy sound

____ fibers of auditory nerve connect to inner hair cells

Afferent

______ fibers connect to outer hair cells

Efferent

All of the following are part of the outer ear

Pinna, External Auditory Meatus, and Lateral surface of tympanic membrane

The main role of the ________ is to allow for the middle ear to transform sound energy from the medium of air to the medium of fluid

tympanic membrane

This ossicle connects with the inner ear at the oval window opening in the bony casing

Stapes

The middle ear muscle that is an integral part of the acoustic reflex is the:

Stapedius muscle, which attaches to the stapes and pulls the footplate away from its attachment to the oval window

The Organ of Corti sits atop the _____ and contains ________

basilar membrane; hair cells

The hair cells in the cochlea are organized tonotopically with hair cells in the _____ more sensitive to higher frequencies and hair cells in the ______ more sensitive to lower frequencies

Base; Apex

Which structure of the outer ear collects sound waves and directs the sound waves into the external auditory meatus (ear canal)?

Pinna

What’s the medical term for ear canal?

External auditory meatus

The footplate of the stapes fits into the bony casing of the inner ear at the oval window pushing on what structure?

Cochlea

What structure is labeled A?

Pinna

What structure is labeled B?

External Auditory Meatus