Study your flashcards anywhere!

Download the official Cram app for free >

  • Shuffle
    Toggle On
    Toggle Off
  • Alphabetize
    Toggle On
    Toggle Off
  • Front First
    Toggle On
    Toggle Off
  • Both Sides
    Toggle On
    Toggle Off
  • Read
    Toggle On
    Toggle Off
Reading...
Front

How to study your flashcards.

Right/Left arrow keys: Navigate between flashcards.right arrow keyleft arrow key

Up/Down arrow keys: Flip the card between the front and back.down keyup key

H key: Show hint (3rd side).h key

A key: Read text to speech.a key

image

Play button

image

Play button

image

Progress

1/5

Click to flip

5 Cards in this Set

  • Front
  • Back
TYMPANIC CAVITY

POSTERIOR WALL
-"ADITUS & ANTRUM"

-"PYRAMIDAL EMINENCE"
5. Posterior wall

a. An irregular aperture, the aditus ad antrum, is located superiorly on
the posterior wall; it is continuous posteriorly with an expanded
chamber, the mastoid antrum, which, in turn, is continuous with the
mastoid air cells

b. The pyramidal eminence, a hollow, volcanolike projection, lies infe-
rior to the aditus ad antrum
TYMPANIC CAVITY

MEDIAL WALL

PROMONTORY
-describe
-within mucosal covering...
6. Medial wall

a. Promontory

1. Round bulge located centrally on the medial wall; produced by
the basal turn of the cochlea

2. Within its mucosal covering lies a nerve network, the tympanic
plexus, which is formed by the caroticotympanic nerves and the
tympanic branch of the glossopharyngeal nerve; the tympanic
branch of the glossopharyngeal nerve is composed ofpregangli-
onic parasympathetic fibers from the inferior salivatory nucleus
in the brainstem as well as general sensory fibers
TYMPANIC CAVITY

MEDIAL WALL
PROMONTORY

-TYMPANIC PLEXUS
6. Medial wall
a. Promontory

3. The tympanic plexus gives rise to the lesser petrosal nerve, which
traverses a small canal near the semicanal for the tensor tympani,
emerges into the middle cranial fossa through the hiatus for the
lesser petrosal nerve, continues anteriorly in the sulcus for the
lesser petrosal nerve, and exits the skull through foramen ovale
to reach the subjacent otic ganglion; preganglionic parasympa-
thetic fibers within the lesser petrosal nerve synapse in the otic
ganglion (postganglionic sympathetic fibers from the carotico-
tympanic nerves pass through without synapse) and postgangli-
onic parasympathetic secretomotor fibers from the otic ganglion
are distributed to the parotid gland via the auriculotemporal and
facial nerves
TYMPANIC CAVITY

MEDIAL WALL
-"ROUND WINDOW"
6. Medial wall

b. Round window (fenestra cochleae): round opening posteroinferior to
the promontory; it is closed in life by the secondary tympanic mem-
brane, which undergoes compensatory movements opposite those of
the pistonlike stapes
TYMPANIC CAVITY

MEDIAL WALL
-"OVAL WINDOW"
c. Oval window (fenestra vestibuli): oval opening superior to the prom-ontory; it is closed in life by the base of the stapes and annular liga-
ment