Anatomy Of The Ear Flashcards
What components make up the external ear?
Pinna
External auditory meatus
Lateral surface of tympanic membrane
What is another name for pinna?
Auricle
What bone of the skull houses the ear?
Temporal
What are the components of the temporal bone?
Squamous
Petromastoid
Tympanic plate
Styloid process
What part of the temporal bone contains the middle and inner ear?
The petrous part
What is the auricle made of?
Elastic cartilage covered by skin
What is the outer rim of the auricle called?
Helix
What does the tragus guard?
The external acoustic meatus
What shape is the external acoustic meatus?
Sigmoid- need to pull ear up and back to straighten when examining
The external acoustic meatus has a cartilaginous outer third and…
Bony inner third
Which part of the external acoustic meatus has hairs and produces wax?
Cartilaginous part
How long is the EAM?
2.5cm
The EAM is lined with skin secreting cerumen - what is this?
Modified sebum
What is wax made of?
Discarded cells of skin and cerumen
What is the function of the auricle?
Capture and direct sound waves towards the EAM
What is the only part of the external ear not supported by cartilage?
The lobule - fat
What is the second innermost curvature of the auricle called?
The antihelix
The antihelix divides into…
Two cura - inferoanterior crus and superoposterior crus
In the middle of the auricle is a hollow depression called the …
Concha - continues into skull as EAM
What lies opposite to the tragus?
Antitragus
The external ear is supplied by branches of what artery?
External carotid artery
What branches of the external carotid artery supply the external ear?
Superficial temporal
Posterior auricular
Occipital
Maxillary - deep auricular branch
What supplies the upper lateral surface of the auricle?
Auriculotemporal nerve (branch of CNV mandibular division)
What innervates the lower lateral and medial surface of auricle?
C3 greater auricular nerve
What innervates the superior medial surface of auricle?
C2/3 lesser occipital nerve
What innervates the EAM?
Auricular branch of vagus
What is another name for ear drum?
Tympanic membrane
What shape is the tympanic membrane?
A shallow cone, with apex pointing medially
The apex of the tympanic membrane is attached to what bone?
The malleus
Is it possible to see structures in the middle ear during otoscopy?
Yes the tympanic membrane is translucent