Ear Flashcards
what does the organ of corti contain?
the receptors for the auditory apparatus
what makes up the inner ear?
in the petrous part of the temporal bone
contains a membranous and a bony part
series of canals that interconnect
vestibular and cochlear, with cochlear ducts
what are the 3 bones that are contained within the middle ear?
malleous
stapes
incus
what is the function of the malleus, incus and stapes?
transmit sound from the tympanic membrane to the middle ear
what are the 2 muscles associated with the middle ear?
stapedius
tensor tympani
what does the stapedius do?
tightens the annular ligament
reduces osciltatory range
what is the innervation of the stapedius?
the facial nerve
what can an infection of the middle ear lead to in terms of nervous problems?
a lesion of the facial nerve
what innervates the tensor tympani?
the auriculotemporal branch of Viii
what is the function of the tensor tympani?
it functions to pull the tympanic membrane to dull the transmission of sound
where does the Eustachian tube connect?
the pharynx and the middle ear
what is the significance of the Eustachian tube in a child?
it is straighter, therefore more prone to middle ear infections as the respiratory infection can back up the tube
what is the arterial supply of the Eustachian tube?
middle menangial artery
ascending pharyngeal artery
artery of the pterygoid canal
what is the venous drainage of the Eustachian tube?
the pterygoid venous plexus
what is the nerve supply of the Eustachian tube?
tympanic plexus
pterygoid plexus
glossopharyngeal nerve
what is the lymph drainage in the Eustachian tube?
the deep cervical lymph nodes
what is the function of the Eustachian tube?
to equalise pressure between the nasopharynx and middle ear
what are the borders of the tympanic cavity?
anterior - carotid border posterior - mastoid floor - jugular roof - tegmen tympani bone lateral - tympanic membrane medial - the inner ear
what are the contents of the middle ear?
the tympanic membrane the 3 bones the auditory tube resp epithelium mastoid air cells chorda tympani nerve tympanic plexus nerve
describe the tympanic membrane
it is 1cm
3 layers - skin, fibrous and mucous membrane with resp epithelium
seperates middle and outer ear
connects to the malleus
external - auriculotemporal nerve, internal auricular branch of vagus
describe the external acoustic meatus
2-3cm long sigmoid 1/3 cartilaginous with skin from external covering 2/3 bony hairs all way along contains cerumen and sebaceous glands
what is the innervation of the external acoustic meatus?
the lesser occipital nerve
the auriculotemporal branch of v
auricular branch of vagus
facial nerve
describe the sensory innervation of the auricle
greater auricular nerve
auriculotemporal nerve anterior to the external acoustic meatus
lymph drainage of the external ear
deep cervical
superficial cervical
mastoid
superficial parotid
what is the arterial supply of external ear
posterior auricular
superficial temporal
what is the auricle made from?
cartilage
what happens if there is a haematoma within the auricle?
loss of blood supply to cartilage
if undrained, builds up and turns into fibrous tissue causing cauliflower ears
