Bates - Chapter 13: Ears and Nose
What comprises the external ear? -
☑️ auricle and ear canal
Where does the ear canal open? -
☑️ Behind the tragus
How long is the ear canal? -
☑️ 24mm long
what encases outer 1/3 of ear canal -
☑️ Cartilage
What covers the cartilage of the ear canal? -
☑️ Hair-bearing skin and contains glands that produce cerumen
The inner 2/3 of the canal are surrounded by what? Lined by what? -
☑️ Surrounded by bone
Lined by thing, hairless skin
What does pressure on the inner 2/3 of the canal area cause? -
☑️ Pain
What is the tympanic membrane (TM)? -
☑️ a concave disk-like structure that is the border between the outer and middle ear
What is another name for the TM? -
☑️ Eardrum
What does the external ear do? -
☑️ captures sound waves for transmission into the middle and inner ear
What is located in the middle ear? -
☑️ ossicles
What are the 3 ossicles? -
☑️ malleus (hammer), incus (anvil), stapes (stirrup)
What do the ossicles do? -
☑️ Tiny bones that function to transform sound vibrations from the external ear into
mechanical waves that then travel through the inner ear
What are the chief landmarks of the TM? -
☑️ Handle and short process of the malleus
What is the cone of light? -
1
, ☑️ a triangular reflection observed during an ear examination when the light of an
otoscope is focused on the image of the malleus
How does the middle ear connect to the nasopharynx? -
☑️ Proximal end of the eustachian tube (ET)
What does the ET do? -
☑️ Ventilate the middle ear space
Allows for pressure regulation btw middle ear and surrounding environment
Drains mucus from the middle ear into the nasopharynx
What in included in the inner ear? -
☑️ Cochlea
Semicircular canals
Otolith organs housed in the vestibule
Distal end of auditory nerve
What are other names for the auditory nerve? -
☑️ Vestibulocochlear nerve
CN VIII
What is the cochlea dedicated to? -
☑️ Hearing
What are the semicircular canals and otolith organs dedicated to? -
☑️ Balance
What do the cochlea, semicircular canals and otolith organs combine to form? -
☑️ Labyrinth
What is the pathway of hearing? -
☑️ Pinna --> Ear Canal --> Tympanum --> Ossicles --> Cochlea
What are the two phases of the hearing pathway? -
☑️ Conductive phase (external to middle ear)
Sensorineural phase (inner ear)
Hearing disorders of the external and middle ear cause what? -
☑️ Conductive hearing loss
What are possible causes of conductive hearing loss involving the external ear? -
☑️ Cerumen impaction
Infection
Trauma
SCC
Benign bony growths
What is otitis externa? -
☑️ inflammation of external auditory canal aka "swimmer's ear"
2
What comprises the external ear? -
☑️ auricle and ear canal
Where does the ear canal open? -
☑️ Behind the tragus
How long is the ear canal? -
☑️ 24mm long
what encases outer 1/3 of ear canal -
☑️ Cartilage
What covers the cartilage of the ear canal? -
☑️ Hair-bearing skin and contains glands that produce cerumen
The inner 2/3 of the canal are surrounded by what? Lined by what? -
☑️ Surrounded by bone
Lined by thing, hairless skin
What does pressure on the inner 2/3 of the canal area cause? -
☑️ Pain
What is the tympanic membrane (TM)? -
☑️ a concave disk-like structure that is the border between the outer and middle ear
What is another name for the TM? -
☑️ Eardrum
What does the external ear do? -
☑️ captures sound waves for transmission into the middle and inner ear
What is located in the middle ear? -
☑️ ossicles
What are the 3 ossicles? -
☑️ malleus (hammer), incus (anvil), stapes (stirrup)
What do the ossicles do? -
☑️ Tiny bones that function to transform sound vibrations from the external ear into
mechanical waves that then travel through the inner ear
What are the chief landmarks of the TM? -
☑️ Handle and short process of the malleus
What is the cone of light? -
1
, ☑️ a triangular reflection observed during an ear examination when the light of an
otoscope is focused on the image of the malleus
How does the middle ear connect to the nasopharynx? -
☑️ Proximal end of the eustachian tube (ET)
What does the ET do? -
☑️ Ventilate the middle ear space
Allows for pressure regulation btw middle ear and surrounding environment
Drains mucus from the middle ear into the nasopharynx
What in included in the inner ear? -
☑️ Cochlea
Semicircular canals
Otolith organs housed in the vestibule
Distal end of auditory nerve
What are other names for the auditory nerve? -
☑️ Vestibulocochlear nerve
CN VIII
What is the cochlea dedicated to? -
☑️ Hearing
What are the semicircular canals and otolith organs dedicated to? -
☑️ Balance
What do the cochlea, semicircular canals and otolith organs combine to form? -
☑️ Labyrinth
What is the pathway of hearing? -
☑️ Pinna --> Ear Canal --> Tympanum --> Ossicles --> Cochlea
What are the two phases of the hearing pathway? -
☑️ Conductive phase (external to middle ear)
Sensorineural phase (inner ear)
Hearing disorders of the external and middle ear cause what? -
☑️ Conductive hearing loss
What are possible causes of conductive hearing loss involving the external ear? -
☑️ Cerumen impaction
Infection
Trauma
SCC
Benign bony growths
What is otitis externa? -
☑️ inflammation of external auditory canal aka "swimmer's ear"
2
