External Acoustic Meatus & Perforation of the Tympanic Membrane Flashcards
what is the external acoustic meatus?
a sigmoid shaped tube
where does the external acoustic meatus extend?
from the deep part of the concha to the tympanic membrane
how are the walls of the external acoustic meatus given their structure?
by cartilage from the auricle, and bony support from the temporal bone
what is the sensory innervation to the external acoustic meatus?
from branches of the mandibular and vagus nerves
how can the path of travel of the external acoustic meatus be described? (general)
The external acoustic meatus does not have a straight path, and travels in an S-shaped curve
specific path of travel of the external acoustic meatus?
Initially travels in a superoanterior direction
Turns slightly to move superoposterior
Ends in an inferoanterior direction
where does the external acoustic meatus end?
at the tympanic membrane
structure of the tympanic membrane?
has a double layered structure, covered with skin on the outside and a mucus membrane on the inside
what is at the core of the tympanic membrane?
connective tissue
what is the CT at the core of the tympanic membrane connected to?
It is connected to the surrounding temporal bone by a fibrocartilaginous ring
what is the tympanic membrane?
The tympanic membrane is translucent, therefore structures within the middle ear can be seen
what attaches to the inner surface of the tympanic membrane? called?
the handle of malleus attaches to the tympanic membrane, at a point called the umbo of tympanic membrane
where does the handle of malleus continue?
continues superiorly, and at its highest point, a small projection can be see
what is the small projection at the highest point of the handle of malleus called?
the lateral process of malleus
what are the parts of the tympanic membrane moving away from the lateral process called?
the anterior and posterior malleolar folds
