Flashcards in Lecture 27 DA Deck (73)
What is the outer ear?
What does the auricle do?
What is the auricle supported by?
Supported by cartilage, aside from the lobule inferiorly.
What is the outermost ridge of the ear called?
What is the ridge medial to the helix called?
What is the ridge inferior to the antihelix and directly superior to the lobule called?
What is the bump medial to the ear canal called?
What is the space between the ear canal and the antihelix called?
Which portion of the entire ear is cartilaginous?
The outer lateral 1/3rd is cartilaginous, the rest is bony, from temporal bone.
What does the ear canal lead into?
External acoustic meatus.
What is the external acoustic meatus lined by, and what purpose does this serve?
Lined by hairy skin and cerumen glands, which produce cerumen/ear wax.
What is the purpose of ear wax?
Prevents maceration of skin with water.
What is the ear innervated by posteroinferiorly?
By vagus nerve.
What is the ear innervated by anterosuperiorly?
Which division of the trigeminal nerve does the auriculotemporal nerve originate from?
V3/mandibular division of the trigeminal nerve.
Where does the auriculotemporal nerve orginate from?
What innervates the external surface of the tympanic membrane?
What effect does the malleus bone have on the tympanic membrane?
An indentation is formed.
What is the tympanic membrane?
What shape is the tympanic membrane laterally, and what does it depend on?
It is concave laterally, and depends on pressure medially which can turn it convex.
How can a physician detect a problem with the ear using light?
By shining light into the ear and looking at the anteroinferior quadrant, if the position of the beam of light produced changes, then there is a problem with the middle ear.
Where is the tympanic cavity proper found?
Just medial to the tympanic membrane.
Where is the epitympanic recess found?
Just superior to the tympanic membrane.
What was a pre-modern technique used to treat middle ear infections?
Drilling into the mastoid bone to drain the ear.
Where is the auditory tube found relative to the tympanic membrane?
Inferior and medial.
What does the auditory tube connect the tympanic membrane to?
To the pharynx.
Is the pharynx bony or cartilaginous?
What is the tympanic end of the auditory tube embedded in?
Is the auditory tube difficult for bacteria to infect? Why?
Yes it is, as it is on a decline, so it can drain well, and is difficult for bacteria to migrate.