Ear anatomy Flashcards
What is the function of the ears?
Sound and balance
What is the nerve supply to the ear?
Superior anterior quarter - Mandibular division of trigeminal
Rest - Lesser occipital and great auricular nerves (C2/3)
Vagus and facial for parts of the external acoustic meatus
What are the features of the tympanic membrane?
Incus, Hnalde of malleus, cone of light
What are the names of the parts of the external ear?
Helix, Lobule, Tragus, Concha
What are the features of the middle ear?
3 ossicles (malleus, incus and stapes), Air filled chamber, Pharyngotympanic tube
What are the epithelial linings of the ear?
Outer ear - Stratified squamous
Middle ear - simple squamous
What are the functions of the paryngotympanic tube?
Equalise pressure, mucous clearance, dampens loud sounds
What are the muscles of the ear?
Tensor tympani - Attaches to malleus and tenses with loud noises (mandibular division of trigeminal)
Stapedius - Attaches to stapes and contracts with loud noises (facial nerve)
What are the Adenoids?
Nasal tonsils which atrophy naturally at ~10 years old
What is the structure of a synovial joint?
Fibrous articular capsule, synovial mambrane, fluid cavity, articular cartilage
What are the aperatures of the middle ear?
Aditus to the mastoid antrum
Oval window
Round window
Semi-circular canal of inner ear
What lies superiorally and inferiorally to the middle ear?
Superior - Thin layer of temporal bone, Brain
Inferior - Skull internal jugular vein
What lies anteriorally and posteriorally to the middle ear?
Anterior - Nasopharynx, internal carotid
Posterior - Mastoid
What lies medially to the middle ear?
Inner ear then brainstem
Which embryonic structure becomes the external acoustic meatus?
1st pharyngeal groove
