External ear: auricle & auricular haematoma Flashcards
how can the ear be split?
into 3 parts:
external, middle and inner
how can the external ear be split?
functionally and structurally split into two sections: the auricle (or pinna), the external acoustic meatus
what is the auricle?
an external, lateral paired structure
what is the function of the auricle?
capture and transmit sound to the external acoustic meatus
what does most of the auricle contain?
a cartilaganious framework
which is the only part of the external ear not supported by cartilage?
the lobule
what is the helix?
outer curvature of the ear
what is the antihelix?
Moving inwards from the helix, there is another curved elevation, which is parallel to the helix
what does the antihelix divide into?
two cura:
the inferoanterior crus
the superoposterior crus
what is the concha of auricle?
In the middle of the auricle is a hollow depression
what does the concha of auricle continue to? as?
It continues into the skull as the external acoustic meatus
what is the function of the concha?
acts to direct sound into the external acoustic meatus
what is the tragus?
Immediately anterior to the start of the external acoustic meatus is an elevation of tissue
what opposite the tragus?
antitragus
where does Cutaneous innervation to the skin of the auricle (cartilage external ear) come from?
the greater auricular, lesser occipital and branches of the facial and vagus nerves
why do patients complain of an involuntary cough when cleaning their ears?
this is due to stimulation of the auricular branch of the vagus nerve, the nerve responsible for the cough reflex
With respect to the vasculature, what are the main vessels involved in supplying the auricle?
the posterior auricular, superficial temporal and occipital arteries and veins
what is an auricular haematoma?
when blood collects between the cartilage and the overlying pericondrium
how is an auricular haematoma normally caused?
trauma, contact sports
what can auricular haematoma lead to?
the accumulation of blood in auricular haematoma can disrupt the blood supply to the cartilage of the auricle (diffusion, avascular tissue)
what is ‘cauliflower ear’?
the gross deformity that occurs if the accumulation of blood within auricular haematoma is not drained quickly
