Outline 16 - Ear Flashcards
___ ____ can lead to meningitis
ear infection
parts of Outer ear, external ear
a. Pinna
b. Tragus
i. Intertragic notch
ii. Antitragus
c. Helix
i. Crux
ii. Auricular tubercle
iii. Lobule or lobe
d. Antihelix
i. Crura
e. External acoustic meatus
i. Concha of auricle
Remember, that the ___ ear drains through the Eustachian tube and the tarus tubarius (the opening to the Eustachian tube)
Middle
Middle Ear** (Parts)
a. Ear drum or tympanic membrane : vibrates differently according to different pitches, Hz, sound. Look for the Cone of Light. If you don’t see it, that’s an indicator of a disease/infection. The ear drum also should not be torn, scarred, bulging out, or sucking in.
b. Ossicular chain, ossicles : tiny bones. When the ear drum vibrates, it moves the handle of the malleus, which moves the other bones. Joints between these bones are synovial joints.
i. Hammer – Malleus
ii. Anvil – Incus
iii. Stirrup – Stapes : the foot of the stapes is pressed up against the Oval Window.
iv. Oval window : membranous. Vibrates with the movement of the Ossicular Chain which then moves fluid in the INNER ear.
v. Round window : squeezes the balloon and will vibrate. Think of water in a balloon.
* Mucus membrane is in the middle ear. Can close off the middle ear when sick.
fluid-filled. Closed system. No air exchange. There is movement of the fluid/a change in pressure. Critical to balance.
What part of the ear is this?
Inner Ear
Inner Ear***
a. Otic capsule or labyrinth
i. Semicircular canals : 3 (?) of them. Also help with balance.
ii. Cochlea : organ of hearing. Acoustic nerve and vestibular portion of the acoustic nerve (??). Fluid movement in the cochlea transmits pitch. We hear pitch and timbre (quality of sound) because of mechanical movement. They are transmitted through fluid in the inner (?) ear.
iii. VIII Vestibulocochlear (Cranial Nerve): cochlea and semicircular canals.
1. Vestibular branch
2. Cochlear branch
