Functional Anatomy And Disorders Of The Ear Flashcards
What is the ear for?
Hearing and balance
What are the three parts of the ear?
External Middle Inner
What are the symptoms and signs of ear disease?
Otalgia (ear pain) Tinnitus Discharge Vertigo Hearing loss Facial nerve palsy
Why Can otalgia be referred pain from another site?
Diverse sensory innervation of the ear If share similar nerve innervation e.g. Laryngeal cancers
Within which bone of the skull do we find the parts of the ear?
Temporal bone
peatrus part of temporal bone
What is the external ear made up of?
Pinna External auditory meatus Lateral surface of tympanic membrane
What does the external ear do?
Collects Transmits and focuses sound waves onto tympanic membrane
What abnormalities of the pinna are there?
?
What causes a pinna haemotoma?
Secondary to blunt injury to the pinna (Compact sports)
What is a pinna haemotoma?
Accumulation of blood between the cartilage and perichondrium Deprives the cartilage of its blood supply and pressure necrosis of tissues
What is the treatment of pinna haematoma?
Prompt drainage Measures to prevent reaccumulation or reap position of two layers
What is the deformity if pinna haematoma is not treated properly?
Cauliflower deformity As leads to fibrosis and new asymetrical cartilage develops
What is the external acoustic meatus?
Ear canal (skin lined cul de sac)
What shape is the external acoustic meatus?
Sigmoid shape Pull Up and back when examining
What is the external acoustic meatus made of?
Outer 1/3 cartilage Inner 2/3 bony
Where is hair and waves produced within the external acoustic meatus?
Cartilaginous part
What does wax and hairs do within the external acoustic meatus?
Prevents objects entering deeper into the ear canal Aids in desquatmation and skin migration out of canal
How long is the external acoustic meatus?
Around 2.5 cm
What are some common conditions of the external acoustic meatus?
Wax Otitis externa
What are some common abnormalities of the tympanic membrane?
Perforation Bulging secondary to otitis medulla
What is the middle ear made up of?
Ossicles and an air filled cavity
What does the air filled cavity contain?
Three ossicles which amplify vibrations from the tympanic membrane to the choclea via the oval window
What are the three ossicles?
Malleus Indus Stapes
What are the ossicles connected by?
Synovial joints