4.6 Ear Flashcards
What structures make up the external ear?
pinna and external acoustic meatus
What ossicle is attached to the deep surface of the tympanic membrane?
malleus
What muscle attaches to the malleus and what innervates it?
tensor tympani m. (CN V3)
What does the stapes attach to?
oval window of cochlea
What muscle attaches to the stapes and what innervates it?
stapedius m. (CN VII)
What compromises the bony labyrinth of the inner ear?
vestibule, semicircular canals and cochlea
What is the bony labyrinth filled with?
perilymph
What is the membranous labyrinth filled with?
endolymph
What nerve supplies the external surface of the tympanic membrane?
auricular branch (CN X)
What nerve supplies the internal surface od the tympanic membrane?
tympanic n. (CN IX)
What separates the external from the middle ear?
tympanic membrane
Which portion of the mandible can be palpated by placing the small finger into the out part of the external ear canal?
mandibular condyle
What nerve passes between the malleus and the incus?
Chorda tympani (CN VII)
What is the function of the oval window?
translates mechanical vibrations of ossicles into waves of fluid that fills cochlea
What is the function of the round window?
dissipates pressure waves generated by mechanical vibrations
How does the oval window relate to the promontory?
near upper pole of promontory
How does the round window relate to the promontory?
near lower pole of promontory
What structure forms the promontory?
initial part of spiral bony cochlea, bulges into middle ear cavity in form of round projection on medial wall of cavity