EXAM 1 - Hearing

Hearing

20 to 20000 Hz

Speech

1500 to 5000 Hz

>90 dB

Causes damage

Outer ear

Auricle

Helix

Auditory Canal

Auricle (pinna)

Entire ear

Gathers sound waves

Auditory canal

External acoustic meatus

In temporal bone

Creates acidic environemnt to kill bacteria

Cerumen (earwax)

Middle ear

Tympanic membrane

Auditory tube

Tympanic membrane

Vibrates

Middle ear ossicles

Malleus (T.M)

Incus (Middle)

Stapes (Oval on cochlea)

Auditory (Eustachian) tube

Connects middle ear to nasopharynx

Equalizes air pressure

Both sides of T.M

Stapedius muscle attaches to

Stapes (Oval window)

Tensor tympani muscles attach to

Malleus (T.M)

In children auditory (eustachian) tube is

Short

Horizontal

Inner ear

Vestibule

Cochlea

Vestibulocochlear (8)

VII

Hearing

Balance

Anterior semicircular duct

Saggital plane

Nodding yes

Posterior semicircular duct

Frontal

Cerv. lateral flexion

Cerv. ABD

Lateral semicircular ducts

Transverse plane

Nodding no

3 chambers of cochlea

Scala vestibuli

Scala tympani

Scala media

Scala vestibuli location and liquid and border

Superior

Perilymph

Vestibular membrane

Scala tympani location and liquid and border

Inferior

Perilymph

Scala media (cochlea duct) location and liquid

Middle chamber

Endolymph

Spiral organ

Spiral organ

Organ of corti

Transduction

Hair cells

Surrounded by fluid

Inner hair cells

Provides for hearing

Outer hair cells

Different frequencies

Over 90 dB tensor tympani pulls on the tympanic membrane & doesn’t allow it to vibrate

Protects vestibulocochlear nerve

K+ flows in (Hair cells)

Depolarization

K+ depolarizing membrane

Stimulates cochlea nerve

Base of cochlea

Proximal

Stapes attaches to oval window

Higher freq.

Apex of cochlea

Distal

Dont need a lot of movement

Low freq.

First order

Cochlea to medulla oblongata

Second order

Medulla oblongata to pons

Third order

Pons to thalamus

Fourth order

Thalamus to primary auditory cortex

Otosclerosis is when ossicles not moving properly bc of

Arthritis

Sensorineural (nerve) deafness

Cochlear nerve damaged

Loud noise

Sensorineural VS. Conductive

Weber test

Mastoid process

AC>BC

Renee test

Semicircular ducts

Anterior

Lateral

Posterior

At the base of each semicircular ducts, is an enlargement that is called

Ampulla

Crista ampullaris

Hair cells

Ampulla is also where the hair cells

Bend