Lab #16 Ear

external auditory meatus

Canal- Narrow external opening that prevents large objects from entering and damaging the tympanic membrane.

inner hair cells

Detect displacement of the basilar membrane

The auricle and external acoustic meatus are part of the ________ ear.

External

tympanic membrane (eardrum)

Funnel shaped membrane composed of fibrous connective tissue sandwiched between two epithelial sheets it serves as a boundary between the external and middle ear it vibrates when sound waves hit it and it's vibrations provide the means for transmission of sound wave energy from the external ear to the middle ear

Middle Ear Infection (Otitis Media)

Infectious Agents move from the nasopharynx through the Auditory tube into the middle ear

malleus

Long handle, expandable end Resembles hammer in shape The long handle has contact with the tympanic membrane which transmits vibrations to the incus.

The Auditory ossicles are located in the _____ ear

Middle

The region of the inner ear where mechanical energy of the stapes is converted to pressure waves in the cochlea

Oval window

auditory tube (pharyngotympanic tube, eustachian tube)

Passageway that extends from the middle ear into the nasopharynx. Tube is normally closed. Air movement occurs as a result of chewing yawning and swallowing- Helps to equalize air pressure on each side of tympanic membrane.

The location where excess pressure waves exit the inner ear

Round window

The structures responsible for detecting head position equilibrium when the body is rotating.

Semicircular Canals

The Auditory Ossicles that tap on the oval window

Stapes

synonym for the ear drum

Tympanic membrane

The cranial nerve that takes information from the inner ear to the temporal bone

Vestibulocochlear

cerumen

Waxlike secretion that combines with sloughed skin cells to form the 'earwax' This material helps reduce infection with the external acoustic meatus by impeding microorganisms

auricle (pinna)

funnel-shaped, protects the entry into the ear, directs sound waves into the boney tube called the external acoustic meatus

vestibulocochlear nerve

hearing and balance

The middle auditory ossicle

incus

round window

located just below the oval window; dampens vibrations in the perilymph

The most lateral auditory ossicle

malleus

auditory ossicles (tympanic cavity)

malleus, incus, stapes ( lateral to medial 'MIS') 3 bones positioned between the tympanic membrane and the round window) Amplify sound waves from the tympanic membrane to the oval window. Auricle ► external acoustic meatus ► tympanic membrane ► (ossicles) malleus ► incus ► stapes ► oval window The movement of the ossicles initiate pressure waves in the fluid within the close compartments of the inner ear

oval window

membrane at the enterance to the cochlea through which the ossicles transmit vibrations

ceruminous glands

modified sweat glands, located in external ear canal, secretes cerumen (earwax)

inner ear

oval window vestibule -utricle -saccule semicircular canals cochlea round window vestibulocochlear nerve

Another name for the auditory canal

pharyngotympanic tube

synonym for the auricle

pinna

stapes

stirrup (arch and plate of bone) Fit into oval window and anchored by small ligaments last of the three auditory ossicles of the middle ear

utricle

the larger of two sacs within the membranous labyrinth of the vestibule in the inner ear

saccule

the smaller of two sacs within the membranous labyrinth of the vestibule in the inner ear

semicircular canals (part of the bony labyrinth)

three canals within the inner ear that contain specialized receptor cells that generate nerve impulses with body movement

middle ear

tympanic membrane tympanic cavity -auditory ossicles -malleus incus stapes pharyngotympanic tube (auditory tube)

2 parts of the vestibule

utricle and saccule

sound pathway

Auricle ► external acoustic meatus ► tympanic membrane ► (ossicles) malleus ► incus ► stapes ► oval window ► cochlea ►Scala vestibule► basilar membrane ►inner hair cell ► cochlear nerve CN VIII ► synapse in medulla oblongata ► pons ► synapse in inferior colliculus (midbrain) ► synapse in thalamus ► primary auditory cortex ► auditory association area

The external acoustic meatus is a hole through which bone of the skull

Temporal

Pain associated with tympanic membrane

Trauma to the Tympanic membrane is transmitted to the brain along sensory neurons within both the Vegas and trigeminal nerves

cochlea

a coiled, bony, fluid-filled tube in the inner ear through which sound waves trigger nerve impulses

incus

a small anvil-shaped ossicle bone in the middle ear, transmitting vibrations between the malleus and stapes.

basilar membrane

a structure in the inner ear that undulates when vibrations from the ossicles reach the cochlear fluid

tympanic cavity (middle ear)

air-filled space containing auditory ossicles, round windows, oval windows and connects inferiorly to the auditory tube

2 parts of external ear

auricle (pinna) external acoustic (auditory) meatus

scala vestibuli

contains perilymph

vestibule

contains utricle and saccule