Chapter 15 -- Hearing and Balance Flashcards
What are the three main areas of the ear?
External ear: (hearing). Terminates at eardrum
(tympanic membrane). Includes auricle and external auditory meatus
Middle ear: (hearing). Air-filled space containing auditory ossicles
Inner ear: (hearing and balance). Interconnecting fluid-filled tunnels and chambers within the temporal bone
What is the name of the visible protruding part of the ear?
Auricle or Pinna
What is the name of the visible tunnel of our ear?
External Auditory Meatus
What is the name of the membrane of the external ear that vibrates during sound? Describe it.
Tympanic membrane
Sound waves cause it to vibrate
Border between external and middle ear
What are the names of the three bones found in the middle ear?
Auditory Ossicles: Malleus, incus, stapes
What is the border between the middle ear and the inner ear?
The oval window, the foot of stapes rests here.
What is the name of the tube that opens into the pharynx?
Eustachian Tube or Auditory Tube
What are the two labrynths of the inner ear?
Bony Labrynth: chambers in the temporal bone
Membranous: tunnels and chambers in the bony labyrinth
Name the three areas of the ear where we find bondy labyrinth.
Cochlea: hearing
Vestibule: balance
Semicircular canals: balance
What are the two types of lymph or liquid found in the ear?
Endolymph: in membranous labyrinth
Perilymph: space between membranous labyrinth and periosteum of bony labyrinth
What are the two chambers of the cochlea that are filled with perilymph?
scala vestibuli
scala tympani
What type of membrane lines the wall of the scala vestibuli?
vestibular membrane
What type of membrane lines the wall of the scala tympani?
basilar membrane
What is the name of the duct between the scala vestibuli and scala tympani?
Cochlear duct (scala media). Filled with endolymph
Describe the cells found in the cochlear duct
Spiral organ (organ of Corti) are the cells found in the cochlear duct.
Contains:
Supporting epithelial cells and specialized hair cells with stereocilia hair-like projections
What is the function of stereocilia?
They transfer information from one stereocilia to another by use of the tip links mechanically gated ion channel.
Tip link (gating spring) attaches tip of each stereocilium in a hair bundle to the side of the next longer stereocilium.
Describe two of the qualities of sound
Volume or amplitude: function of wave amplitude
Pitch: function of wave frequency
Describe how sound travels through your ear.
- Sound waves strike the tympanic membrane and cause it to vibrate.
- Sound waves strike the tympanic membrane and cause it to vibrate.
- The foot plate of the stapes vibrates in the oval window.
- The vibrations of the oval window causes a vibration through the cochlea and vibrates the perilymph.
What are the two muscles of the middle ear that move the ossicles?
Tensor tympani: inserts on malleus
Stapedius: inserts on stapes
