ear cavity Flashcards
ear
receptor organ for hearing & equilibrium
what are the three main regions of the ear?
external, middle, internal ear
external ear
functions in hearing, transference of sound to the internal ear
middle ear
functions in hearing, narrow air-filled space lined by mucous membrane
internal ear
participates in both hearing and equilibrium
what are the three parts of the external ear
auricle, external acoustic meatus, tympanic membrane
auricle
elastic cartilage, functions to gather and direct sound waves into the external acoustic meatus
external acoustic meatus
short canal running medially from auricle to tympanic membrane and conducting sound
tympanic membrane
forms the boundary between the external and middle ears, moves in response to air vibrations, mucous membrane
what is the innervation of the tympanic membrane?
external surface- auriculotemporal nerve CN V3
small area supplied by CN X
internal surface- CN IX
what are the two parts of the middle ear?
tympanic cavity proper & epitympanic recess
pharyngotympanic tube
connects tympanic cavity to nasopharynx where it opens posterior to the inferior nasal meatus, 1/3 bony, remainder cartilage lined with mucous membrane
what is the function of the pharyngotympanic tube?
equalize pressure in the middle ear with atmospheric pressure to allow free movement of the tympanic membrane, connects middle ear to nasal cavity
vestibulocochlear organ
sound reception and balance maintenance found in internal ear
vestibulocochlear nerve CN VIII
cochlear nerve- hearing
vestibular nerve- equilibrium
