Question | Answer |
What lines the tympanic cavity? | A mucous-secreting membrane. |
Name the three ossicles of the middle ear cavity in order from lateral to medial. | Malleus, incus and stapes. |
Name two muscles found in the middle ear cavity, their innervation and what they attach to. | Stapedius, CN VII, the stapes; tensor tympani, V3, the malleus. |
Name the region of the tympanic cavity found above the head of the malleus. | The epitympanic recess. |
Identify an anterior communication of the middle ear cavity and to what does it
communicate? | The auditory tube, the nasopharynx. |
Identify a posterior communication of the middle ear cavity and to what does it
communicate? | The aditus of the mastoid antrum, mastoid air cells. |
Name two nerves associated with the middle ear cavity | CN VII and CN IX |
What branches does the facial nerve give off to the middle ear cavity and what
modalities do they carry? | The nerve to the stapedius (motor) and the chorda tympani (taste to anterior 2/3 of tongue). |
What branches does the glossopharyngeal nerve give off to the middle ear cavity and
what fibers are carried in it? | The tympanic branch that contributes preganglionic parasympathethetic fibers to the tympanic plexus. |
What two major vessels have an inferior relationship to the middle ear cavity? | The internal jugular vein and internal carotid artery. |
What fibers travel on the surface of the internal carotid artery and to what to they
contribute? | Postganglionic sympathetic fibers (the carotid sympathetic plexus) that are contributed to the tympanic plexus. |
Identify the bulge on the medial wall of the tympanic cavity and what causes it? | The promontory, the cochlea of the inner ear. |
Define the umbo and pars flaccida. | The umbo is the point of attachment of the manubrium of the malleus to the tympanic membrane. The pars flaccida is the uppermost portion of the tympanic membrane that lacks a central fibrous layer and is therefore not as rigid. |
Name one branch given off the intraosseous portion of CN VII that is NOT related
to middle ear structures. What kind of fibers travel in this nerve? | The great petrosal nerve. Preganglionic parasympathetic fibers. |
Name two openings in the medial wall of the tympanic cavity and which of these
contains the footplate of the stapes? | The oval window and round window. The oval window is filled by the footplate of the stapes |
What is the bony cave in the petrous temporal bone forming the middle ear called? | The bony labyrinth. |
What lines this cavity? | The membranous labyrinth. |
What fluid is found within the membranous labyrinth? Between the bony and
membranous labyrinth? | Endolymph. Perilymph. |
What structure(s) of the middle ear comprise the portion dealing with hearing? | The cochlea and cochlear ducts. |
What structure(s) of the middle ear comprise the portion dealing with balance? | The 3 semicircular canals. |
The cochlear duct divides the cochlea into which two spaces? | A superior scala vestibuli, an inferior scala tympani. |
What is responsible for detection of sound vibrations? | The organ of Corti in the flat inferior aspect of the coclear duct - the basilar membrane. |
Which division of CN VIII deals with hearing? With detection of balance/
acceleration? | The cochlear division. The vestibular division. |
What specialized areas of the semicircular canals are responsible for detection of
balance/acceleration? | The maculae of the semicircular canals. |