Ear Anatomy Flashcards
What direction should you pull the pinna to straighten the ear canal of an adult?
Up and back
What direction should you pull the pinna to straighten the ear canal of a child/infant?
Down and back
What bone makes up the inner 2/3 of the external ear canal?
Temporal Bone
Which two glands are found in the outer 1/3 of the external ear canal?
Ceruminous and Sebacious Glands
By what intensity dB does the external ear canal increase sound intensity?
15 dB
The external ear canal increases the sound intensity of what range of frequencies?
2000-4000 Hz
By what intensity dB do the middle ear bones increase sound pressure?
25 dB
Into which window does the stapes bone insert?
The oval window
By which cranial nerve is the stapedius muscle innervated?
Facial (VII)
By which cranial nerve is the tensor tympani muscle innervated?
Trigeminal (V)
What condition may inhibit stapedius muscle contraction?
Bell’s Palsy
To what system to the semicircular canals belong?
Vestibular System
Which system, also known as the inner ear, contains the cochlea?
Auditory System
What is the name of the top chamber of the cochlea which contains parilymph?
Scala Vestibuli
What is the name of the middle chamber of the cochlea which contains endolymph?
Scala Media
What is the name of the bottom chamber of the cochlea which contains perilymph?
Scala Tympani
What is the name of the opening at the apex of the cochlea which connects the scala vestibuli from scala tympani?
Helicotrema
What is the name of the membrane that separates the scala vestibuli from the scala media?
Reissner’s Membrane
What is the name of the membrane that separates the scala media from the scala tympani?
Basilar Membrane
Where does the Organ of Corti reside?
On the basilar membrane in the cochlea.
What are the steps of the ascending central auditory pathway (aka Chuck SLIMT)?
Cochlear Nucleus, Superior Olive, Lateral Lemniscus, Inferior Colliculus, Medial Geniculate Body, Temporal Lobe
