Exam 4: Ear Flashcards
What are the 3 parts of the ear?
External ear (outer)
Middle ear
Internal ear (inner)
External ear function
conduct sound waves –> middle ear
Auricle
pinna - part of external ear we see
External acoustic meatus
cone-shaped structure toward skull
aka: ear canal
The external ear has a core of _____ covered by (thin/thick) skin.
Elastic cartilage
Thin
What 3 structures are present in the skin of the external ear?
hair follicles
sebaceous glands
apocrine sweat glands
What tissue type lines the external acoustic meatus?
very thin epidermis
keratinized stratified squamous
What kind of glands are present in the external acoustic meatus?
ceruminous glands
What do ceruminous glands secrete?
cerumen = main component of earwax
Function of Middle Ear
conduct sound wave energy –> internal ear
Tympanic membrane
ear drum
outer-most part of middle ear
Which bone attaches directly to the tympanic membrane?
malleus
Tympanic cavity
space from tympanic membrane –> inner ear
What 3 auditory ossicles are in the tympanic cavity of the middle ear?
malleus
incus
stapes
Which auditory ossicle connects to the inner ear? Where exactly does it attach?
stapes
attaches to vestibular/oval window
Scala Vestibuli
where vestibular window connects in inner ear and creates fluid waves
Cochlear/Round Window
membrane that dampens fluid waves in inner ear
The auditory (eustachian) tube connects _____ to _____.
Tympanic cavity –> nasopharynx
What is the function of the auditory tube?
create even pressure on both sides of tympanic membrane
What layers make up the tympanic membrane?
two layers of epithelium (each side) + CT between
What two possible tissue types line the tympanic cavity?
simple squamous or simple cuboidal
What is the function of the small skeletal muscles found in the tympanic cavity?
dampen sound waves to protect from damage (stiffen movement of ossicles)
What are the two skeletal muscles in the tympanic cavity?
Tensor Tympani M
Stapedius M
Where does the Tensor Tympani M attach? Stapedius M?
Malleus
Stapes
What tissue type lines the auditory tube?
pseudostratified columnar w/ goblet cells + cilia
What two types are cartilage are present within the auditory tube?
hyaline + elastic
Guttural Pouch
herniation of mucosa of auditory tube in horse
Function of internal ear
convert fluid wave energy –> action potentials
The internal ear is connected to the middle ear by _______.
vestibular/oval window
Where is the internal ear located in the skull?
petrous part of temporal bone (internal acoustic meatus inside it)
3 parts of the bony labyrinth
semicircular canals
vestibule
cochlea
Ampulla
dilation of each semicircular canal where it connects to the rest of the bony labyrinth
Vestibule
entryway between the semicircular canals and cochlea
Cochlea
snail-shaped innermost part of labyrinth