Lecture 28: Ear Flashcards
what are the 3 parts of the ear
inner, middle (tympanic cavity), external
the inner ear is ____ filled space, within the ____ portion of the ______bone
fluid, petrous, temporal
the middle ear is an ____ filled space, within the _____ and ______ portions of the temporal bone
air, petrous and tympanic
the external ear emerged from the tympanic part of the _______ bone and is continued by cartilaginous pieces
temporal
does hearing require any external structures
nah
what is the primary function of the middle ear?
transmit sound vibrations from the lateral external ear to the more medial inner ear
the middle ear is composed of what 3 structures
tympanic membrane (eardrum)
ear ossicles (ossicular chain)
oval window (fenestra ovalis)
what bone transmits vibrations from outside of the head to the inner ear?
stapes, causes the vibrations in the perilymph of the inner ear
all mammals have 2 additional small bones in their middle ear, the _____ and _____
**incus **(b/w other bones of the ossicular chain and articulates w/ them via synovial joints)
**malleus **( body of malleus (manubrium) is fixed to the tympanic membrane so vibrations of membrane are passed along the ossicular chain)
what skeletal muscles in the middle ear are associated with the ossicles
**tensor tympani **(inserts on body of malleus)
**stapedius **(inserts on head of stapes)
both at to clarify hearing and protect from loud ass noises
what CN innervates the tensor tympani
skeletal muscle of middle ear
CN V3 (mandibular n.)
what CN innervates the stapedius
skeletal muscle of middle ear
CN VII (Facial n.)
the mucosal lining of the middle ear sends its sesnory input on the _______ nerve
glossopharyngeal n.
parasympathetics from the glossopharyngeal n pass through the middle ear cavity via the _____ n
**minor pestrol n. **
carries peganglionic parasympathetics from CN IX to the otic ganglion
branch of facial n that carries preganglionic parasympathetic axons from CNVII to the pterygopalatine ganglion
Major pestroal n
branch of facial n that carries both preganglionic parasympathetic input to the mandibular and sublingual ganglia and taste from rostral portion of tongue
Chora tympani
crosses tympanic membrane to get to lingual n
its axons hitch hike to oral cavity via lingual n.
the ______ tube connects the middle ear to the nasopharynx
Auditory (or eustacean or pharyngotympanic)
the auditory tube is typically ______ and must be actively ______ to equalize air pressure
closed, opened
what is otitis media
infection of middle ear cavity
can decress sensitivity of hearing by dampening vibrations of the tympanic membrane and possibly lesion any of the nerves passing through the space
in _____, the tympanic bulba is large and can be palpated
cats
stubborn otitis media can be drained by surgically opening the _______ rostromedially into the nasopharynx
tympanic bulba
externally visible part of the ear…
pinna
in addition to regular sebaceous glands, the skin of the external auditory canal contains special _______ glands
ceruminous glands (earwax)
Branch of superficial temporal artery that supplies some of the rostral concave surface of the ear
Rostral Auricular a.
major branch of the external carotid artery that continues on in 4 branches that supply blood to a majority of the ear
caudal auricular a.
aura hematoma
pooling of blood b/w the ear and the skin that seperates it from underlying cartilage
extensive blood supply to the ears means that even seemingly insignificant trauma can cause….
vascular rupture
sensory innervation from the caudal surface of the auricle is carried by ventral and dorsal rami of….
C2
