132 wk6

An infection with what organism typically causes an otic discharge that is dark brown to black and resembles "coffee grounds" and is most commonly seen in puppies and kittens? How would you diagnose the cause of this abnormal discharge? What is the treatment?

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How do the ear canals of dogs and humans differ?

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List some of the causes of ear diseases. What is the most common cause? Discuss this with your preceptor.

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List some of the commonly used otic medications that have ototoxic potential especially if the tympanic membrane is not intact.

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List some things used to decrease self-trauma to the ear.

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List the steps to clean an ear affected with simple otitis externa. What precautions should you take?

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Long-term use of topical steroids can cause what 2 problems?

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What 2 nerves run through the tympanic bulla? If damaged by inflammation, what can occur?

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What inappropriate treatments may lead to problems or complicate existing ear disorders?

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What is a "progressive infection"?

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What is a common foreign body found in the ear?

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What is an "ascending infection"? (Newman Veterinary website)

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What is the yeast that is found in low numbers in a healthy ear and high numbers with some ear diseases?

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What salivary gland is located near the ear canal?

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What special test is used to determine the degree of deafness in dogs?

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tympanic bulla

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What causes aural hematomas? What are some of the treatment options?

=swelling due to blood vessels that have ruptured inside the ear flap, between the inside and outside layer of cartilage ~removing the fluid and injecting cortisone into the ear. ~oral medication ~surgery

Otitis interna

~Otitis media may lead to otitis interna and inflammation of the inner ear structures.

external ear

~acts as a funnel to collect sound wave vibrations and direct them to the ear drum ~pinna ~external auditory canal ~tympanic membrane (eardrum)

middle ear

~amplifies and transmits the vibrations from the eardrum to the inner ear ~hollowed-out area of the temporal bone that is lined by soft tissue membranes ~ossicles ~eustachian tube (auditory tube) ~cochlea ~malleus (hammer) ~incus (anvil) ~stapes (stirrup)

inner ear

~contains the actual sensory receptors that convert the mechanical vibrations to nerve impulses, along with receptors for the equilibrium sense ~cochlea ~organ of Corti ~cochlear duct ~endolymph ~perilymph ~oval window ~round window ~tectorial membrane

tympanic membrane

~eardrum ~part of the external ear ~paper thin, connective tissue membrane tightly stretch across the opening between the external auditory canal and middle ear cavity

perilymph

~fluid fills U shapped tube in inner ear

endolymph

~fluid that fills the cochlear duct in the inner ear

Otitis media

~inflammation of the middle ear structures ~due to extension of infection from the external ear canal or to penetration of the tympanic membrane by a foreign object

ossicles

~part of middle ear ~3 small bones ~link the tympanic membrane with the cochlea of the inner ear ~systems of levers that transmit the sound wave vibrations form the tympanic membrane to the cochlea

eustachian tube (auditory tube)

~part of middle ear ~connects middle ear cavity with the pharynx ~equalize the air pressure on the two sides of the tympanic membrane

incus (anvil)

~part of middle ear ~middle ossicle bone ~forms a joint with the stapes

stapes (stirrup)

~part of middle ear ~middle-most ossicle bone ~attached to the membrane that covers the oval window of the cochlea

malleus (hammer)

~part of middle ear ~outer most ossicle ~attached to tympanic membrane ~forms a complete synovial joint with the incus

pinna

~part of the external ear ~funnel-like structure composed mainly of elastic cartilage and skin that collects sound wave vibrations and directs them into the external auditory canal

external auditory canal

~part of the external ear ~soft, membrane-lined tube ~begins at the base of the pinna ~carries sound waves to tympanic membrane (eardrum)

tectorial membrane

~part of the inner ear ~gelatin-like ~lies gently on top of the hairs

cochlea

~part of the inner ear ~hearing portion of the inner ear ~snail-shaped spiral cavity in the temporal bone ~

cochlear duct

~part of the inner ear ~long tube

oval window

~part of the inner ear ~membrane-covered openings at the ends of the "U" tube in the inner ear ~located at the base of the cochlear

round window

~part of the inner ear ~membrane-covered openings at the ends of the "U" tube in the inner ear ~located at the base of the cochlear

organ of Corti

~part of the inner ear ~soft, multilayered, fluid filled ~contains receptor organ of hearing ~runs along cochlear duct

What clinical signs may indicate that a foreign body is present in the ear?

Acute onset of head shaking and distress

Underlying causes of otitis externa include which of the following?

Allergic skin disease Tumors in ear canal Ear mites Trauma due to foreign body

Primary disorders which may cause Otitis externa as one clinical sign include:

Atopy / Food allergy Otodectes / Scabies Hyperadrenocorticism / Hypothyroidism Neoplasia

List the diagnostic tests used to diagnose ear disorders.

BAER test- Brainstem Auditory Evoked Response ~

Another name for ear wax is:

Cerumen

Clinical signs of otitis externa include

Discharge / odor Ear scratching / rubbing Head shaking Redness

A dry, brown-black ("coffee ground") ear discharge is often produced as a result of:

Ear mites

The narrow tube that connects the middle ear with the nasopharynx is called the ________ tube:

Eustachian

Which of the following medications have the greatest ototoxic potential if used topically when the tympanic membrane is ruptured?

Gentamycin

In most cases of Otitis externa, common organisms seen on a cytology smear include:

Malassezia Bacteria

The auditory ossicles (malleus, incus, and stapes) are located in the _______ ear.

Middle

List 3 hand-held instruments commonly used when examining ears and removing wax or foreign bodies.

Otoscope Magnifying head Ear cones Alligator forceps ear loop "tom cat"

The portions of the ear that are affected by Otitis externa alone include: (Check all that apply)

Pinna Horizontal ear canal Vertical ear canal

The most appropriate solution to use as an ear cleaner in an animal that has a ruptured ear drum is:

Sterile physiologic saline

An animal with recurrent Otitis, which may be the only sign, may be affected by allergies - either food or inhalant allergies.

True

What 2 secretions are found in the normal ear?

cerumen

Otitis externa.

acute or chronic inflammation of the epithelium of the external ear canal