Lecture (2/20) Week 6 Tuesday Flashcards
The central auditory system is composed of
brain stem
cerebrum (diencephalon & telencephelon)
corpus callosum (1/3 is auditory)
Which bone contains the organs of hearing and balance?
Temporal bone
What are the 4 parts of the temporal bones?
squamous
mastoid process
tympanic
petrous
Describe placement of squamous portion
-in front of and above ear canal
-fan-like
describe the mastoid process
-behind ear
-very thick
-filled with holes
describe the tympanic portion
-forms bottom and sides of ear canal
describe the petrous portion
-medial portion projecting inward
-contains organs of hearing and balance (vestibular system and cochlea)
The outer ear is the most ____ and _____ portion of the auditory pathway
lateral, inferior
the outer ear is part of the _____
peripheral auditory system
What is the auricle or pinna made of
cartilage
What are the parts of the pinna
-helix
-crus helix
-tragus
-cavum concha
-cymba concha
-antihelix
-antitragus
-lobe
-triangular fossa
What divides the concha into 2 areas?
crus helix
what is the upper portion of the concha?
cymba concha
the antihelix separates the ______ from a triangular depression
cymba concha
the _____ is the bump above the lobe
antitragus
what is the most inferior part of the pinna?
lobe
what is the depression above the antihelix and below the helix
triangular fossa
What is the opening to the external auditory canal called?
external auditory meatus
What shape is the external auditory canal?
S-shaped
the external auditory canal extents _____ and _______ for 2.5cm in adults
medially and posteriorly
the EAC begins and ends with a downward slope to allow for _____
drainage
the slope at the end of the external auditory canal may lead to the formation of _____
fungus
Which portion of the EAC contains hair follices?
outer 1/3
the outer 1/3 of the EAC contains sweat glands called
ceruminous glands
what forms wax in the outer 1/3 EAC?
ceruminous glands and sebaceous glands
what portion of the EAC contains no glands or hair?
inner 2/3
the inner 2/3 of EAC pass through the _____ section of the temporal bone
tympanic
What is the point where the outer 1/3 and inner 2/3 of the EAC meet?
osseocartilaginous junction
the osseocartilaginous junction lies directly above the ____ joint
temporomandibular joint
what is a site of secondary pain for TMJ syndrome
osseocartilaginous junction
What are the nerve innervations for the EAC?
trigeminal (V)
facial (VII)
glossopharyngeal (IX)
vagus (X)
coughing is due to what nerve
IX
fainting is due to a combo of what nerves?
IX and X
What lies at the end of the EAC
tympanic membrane
the ear drum is known as the
tympanic membrane
the TM is the _____ between the middle and outer ear
boundary
T/F the outer ear has cosmetic nature
true
the outer ear’s physiology is that it protects
TM
What in the outer ear helps collect foreign objects?
cerumen
T/F cerumen will move itself out of the EAC on its own
true
T/F if cerumen is pulled in too far it will naturally remove itself
false
T/F the pinna and concha act as a resonator (amplifier)
true
The tympanic membrane is the boundary of _____
middle ear
the TM is a structure made from_____ membranes
3
describe the outer layer of the TM
same skin as in the canal
describe the middle layer of TM
elastic conductive laye; fibrous
-one set start at the center and run towards edge (spokes)
-other runs in circles (spiral)
describe the inner layer of TM
same mucous cells as those that line the middle ear cavity
What are the 2 areas of the TM
-pars flaccis
-pars tensa
describe the pars flaccida
-most superior fourth of TM
-does not contain fibers that make the TM very tight
describe the pars tensa-
-inferior 3/4
-very tight/tense
know the anatomy of the TM
look at diagram
what is the surface area of the TM
85mm2
how much of the TM vibrates at any given time
2/3
the TM is attached at the ___ at the center
malleus at the manubrium
place of attachment of TM and malleus manubrium is called
umbo
Describe the localization of the EAC
-help locate sounds from below and above
-high frequency amplifications help in speech perception of consonants, esp in background noise
-helps to color the spectrum of sounds
-theory that an individual gets use to the sound of their own pinna
the TM is held in place at the edges by the
tympanic annulus
know the pinna diagram
look at picture
