External ear (dave's notes) Flashcards
Two words used for the external ear
Auricle/pinna
What does the auricle or pinna consist of?
A skeleton of resilient yellow cartilage, with vestigial intrinsic and extrinsic muscles supplied by the facial nerve
Describe the external acoustic meatus - length/wall size
~3cm long with the anteroinferior wall the longest and the posterosuperior wall the shortest
What tissues does the external acoustic meatus consist of?
Outer 1/3rd cartilage, inner 2/3rds bone
What is the boney part of the external acoustic meatus formed from?
The tympanic part of the temporal bone
What is the cartilaginous part of the external acoustic meatus rich in?
Hair and sebaceous glands
What is the arterial supply of the external ear and external acoustic meatus?
The posterior auricular and superficial temporal arteries
What is the nerve supply to the external ear and external acoustic meatus?
Great auricular, auriculotemporal, vagus and facial