is a crossed and uncrossed tract that arises from the superior
olivary nucleus and projects to the hair cells of the organ of Corti.
suppresses auditory nerve activity when stimulated
Physiology of hearing
Sound waves traveling through air must be
converted into pressure waves in fluid.
The acoustic impedance of fluid is much greater
than that of air.
The combination of the tympanic membrane and ossicles
act as an impedance matching device in order to transfer
the same frequency as the original sound waves.
The hair cells are fixed tightly in the reticular lamina. The reticular
lamina is supported by the rods of corti which are attached tightly to
the basilar membrane
When vibrating, the rods of corti, the
basilar membrane and reticular lamina
move as a rigid unit.
Upward (or downward) movement of the basilar
membrane rocks the reticular lamina upward
and inward (or downward and outward) toward
Hair cells bend toward the longer ones ➝ rapid
movement of K+ from the surrounding Scala media
fluid into the stereocilia ➝ Excitation
Ear pain causes
Ear infection... Air pressure changes... Wax build
up...Strep throat... Foreign object inside ear... Shampoo
trapped in ear...Toothache
Light headedness vs Vertigo
High pitched...Continuous or
intermittent... In the affected
ear... Only you hear it
Heard by the examiner... Blood vessel or
middle ear bone condition
Age...Loud noise... Wax blockage... Head &
neck injuries... Meniere’s disease
Tuning fork ( rinne and weber )
Pure tone Audiometry
Choleosteatoma and aural polyp
What causes a cholesteatoma?
Injury to the eardrum... Chronic
middle ear infections... Eustachian
Definition of aural polyp
a growth in the outside (external) ear canal or
middle ear. It may be attached to the eardrum
(tympanic membrane), or it may grow from the
middle ear space.
chronic suppurative otitis media (CSOM)
Acute otitis media cause persistent perforation.
Ascending infection via Eustachian tube.
Persistent mucoid otorrhea.
Otitis Media: Management and surgery
Ibuprofen or acetaminophen
Topical benzocaine over 2
High dose amoxicillin
Prognosis and complications of otitis media
The severity of the symptoms and the age of the patient determines the
likelihood of success of antibiotic treatment. Acute otitis media in children below
the age of 2 has a poor prognosis. It is associated with an increased number of
recurrences of acute otitis media, as well as the development of otitis media with
effusion 6 months later in 35% of children. Acute otitis media in older age groups
usually resolves on its own without antibiotic treatment.
There are many complications of otitis media. They are classified as
those that occur outside of the brain (extracranial) and those that occur
within the brain (intracranial). These complications are extremely rare
and usually occur in very young children, or those with serious medical
conditions. Extracranial complications occur most commonly, and
include mastoiditis, cholesteatoma and otitis media with perforation.
Intracranial complications are less common, and include meningitis,
brain abscess and lateral sinus thrombosis. In Australia, approximately
60% of extracranial and intracranial complications of otitis media occur