Ear Anatomy Flashcards
Name the 3 parts of the ear
external ear
middle ear
internal ear
What is the function of the external ear?
collects sound waves and directs it towards middle ear
What is the function of the middle ear?
conducts and amplifies vibrations towards inner ear
What is the function of the internal ear?
converts the vibration/movement of fluid into action potentials
What are the special sensory functions of the ear?
hearing
balance
What structure connects the middle ear to the nasopharynx?
Eustachian tube
What is the anastomosis in the brain called that leads to supply blood to the head and neck?
circle of Willis
What are the branches of the external carotid artery? proximal to distal…
superior thyroid artery ascending pharyngeal artery lingual artery facial artery occipital artery posterior auricular artery maxillary artery superficial temporal artery (some anatomists like freaking out poor medical students)
What vein do the veins of the head and neck ultimately drain in to?
internal jugular vein
What special sensory nerve aids hearing and balance?
CN VIII
What special sensory nerve aids taste?
CN VII
CN IX
CN V3
What special sensory nerve aids smell and vision?
CN I
CN II
What is another name for the external ear?
pinna
What is another name for the middle ear?
tympanic cavity
What are the 3 bones called in the tympanic cavity?
malleus
incus (anvil)
stapes
What happens to the ossicles as you go more medially into the ear?
they decrease in size to assist amplification
What kind of joints are present between the ossicles?
synovial joints (smallest in body)
What happens to the tympanic membrane when sound waves reach it?
it vibrates
What muscle attaches to the malleus from the eustachian tube?
tensor tympani muscle
what is the role of the tensor tympani muscle?
dampens sound by reducing the vibrations of the tympanic membrane
what nerve innervates the tensor tympani muscle?
CN V3
Where is the strapedius muscle?
from pyramidal eminence to neck of stapes
What nerve innervates the strapedius muscle?
CN VII
What happens if the atmospheric pressure is greater than the air pressure in the tympanic cavity?
tympanic membrane pushes IN
What happens if the atmospheric pressure is smaller than the air pressure in the tympanic cavity?
tympanic membrane pushes OUT
What general structure does the inner ear have?
dense and bony
name the 2 labyrinths of the inner ear…
bony labyrinth
membranous labyrinth
what does the bony labyrinth contain?
peri lymph
similar to ECF
what does the membranous labyrinth contain?
endo lymph (similar to ICF)
Describe the process of hearing…
1) sound waves making tympanic membrane vibrate
2) vibrations go through ossicles
3) stapes vibrates in oval window
4) creates pressure in peri lymph
5) hair cells in cochlea move
6) APs stimulated and conveyed to brain (cochlear nerve)
7) pressure waves descend and become vibrations
8) dampened at round window
What cells detect auditory stimuli?
hair cells
where are hair cells located?
basilar membrane of cochlear duct
what suspends the cochlear duct?
scala vestibuli
scala tympani
for balance, what detects angular movement change?
semicircular ducts
for balance, what detects linear movement change?
urticle (horizontal)
saccule (verticle)
what nerves pass through the internal acoustic meatus?
CN VII (facial) CN VIII (vestibulocochlear)
What is the result of a dysfunctional facial nerve?
lack of taste on anterior 2/3 of tongue
facial paralysis (Bells palsy)
dry eye, mouth, mucosa
What nerves supply the tongue?
CN IX (glossopharyngeal) - posterior 1/3 CN V3 (trigeminal) - anterior 2/3 CN VII (facial) - anterior 2/3
Name the types taste buds from anterior to posterior…
filiform
fungiform
foliate & vallate
