Middle ear Flashcards
What are the two parts of the tympanic cavity (middle ear)?
tympanic cavity proper and epitympanic recess
What two structures is the tympanic cavity connected to by tubes?
nasopharynx and mastoid cells
How is the tympanic cavity connected to the nasopharynx?
Eustachian tubes
How is the tympanic cavity connected to the mastoid cells?
mastoid antrum
What is contained within the middle ear?
ossicles, stapedius + tensor tympani muscles, openings of the eustachian tube + mastoid antrum and branches of the facial nerve
What is found on the anterior wall of the tympanic cavity?
opening of Eustachian tube, ICA just anterior to the anterior wall, small opening the tensor tympani muscle passes through
What is found on the roof of the tympanic cavity?
made of the tegmen tympani- separates the middle ear from the meninges and temporal lobe
What forms the lateral wall of the tympanic cavity?
the tympanic membrane and the epitympanic recess
What forms the floor of the tympanic cavity?
separates the tympanic cavity from the bulb of the IJV
What is found on the medial wall of the tympanic cavity?
oval window, promontory (formed by basal turn of the cochlea), round window
What is found on the posterior wall of the tympanic cavity?
aditus for the mastoid antrum and the pyramid for the tendon of stapedius
What are the three ossicles?
malleus, incus and stapes
What is attached to the oval window?
base of stapes
What frequency noises are transmitted through the oval window?
high frequency
What joints do the ossicles articulate with one another at?
synovial joints- when sound waves vibrate the tympanic membrane these vibrations pass through the chain of ossicles to the oval window
Which muscles attach to the ossicles?
tensor tympani + stapedius
What do the muscles of the middle ear attach to?
tensor tympani- handle of malleus
stapedius- neck of stapes
What is tensor tympani innervated by?
the mandibular nerve (V3 of trigeminal nerve)
What is stapedius innervated by?
branch of the facial nerve
