Key Terminology & Definitions EAR Flashcards
Otitis
Inflammation of the ear
Primary otits causes
Directly induced inflammation of the external ear canal & therefore can cause the disease by themselves - when infection keeps coming back e.g. Infectious (ectoparasites, fungal, viral), hypersensitivity disorders, immune-mediated skin diseases (puppy strangles)
CAFR
Cutaneous adverse food reaction (CAFR), DDx = atopy
Cystomatosis
Relating to a type of glandular secretion in which the apical portion of the secreting cell is released along with the secretory products
Pustule
Pocket of pus in epidermis, will become a crust (scab)
Actinic dermatitis
Eczema or dermatitis that is caused by abnormal skin sensitivity to sunlight (photosensitivity) = sunburn
Secondary otitis causes
Don’t create disease in a normal ear, they only contribute to or cause inflammation/damage in the abnormal ear e.g. bacteria, yeast, treatment
Staphylococcus histo appearance
Cocci in tetrads/pairs
Streptococci histo appearance
Chains
Perpetuating factors of otitis
Prevent resolution and increase risk of recurrence (relapse) of otitis (alter structure, function + physiology of ear canal, combined with causes, can exacerbate inflammation/symptoms of otitis e.g. progressive pathologic changes, tympanic membrane alterations
Salpingitis
Inflammation of tube e.g. guttural pouch, eustachian tube
Guttural pouch tympany
Pouch filled with air
Guttural pouch empyema
Pus in cavity
Guttural pouch mycosis
Fungi e.g. Aspergillus spp.
Predisposing factors of otitis
Inc the risk of developing otitis but unable to cause clinical disease themselves (need primary + perpetuating factors) e.g. anatomical configuration/conformation
Cytology stained samples from skin, nail, ear
Looks for bacteria, yeast, condenser is up and close to stage, bright light source w/ dec contrast
Cytology microscopy unstained samples in mineral oil
Looks for parasites, condenser is down and away from stage, dim light w/ inc contrast
Myrinogotomy
Procedure to create a hole in the ear drum to allow fluid that is trapped in the middle ear to drain out - cut into tympanic bulla, difficult without video otoscope
Total ear canal obliteration
Remove ear canal = end-stage ear - lose a lot of hearing func
Pinna
(Auricle) - irregularly shaped plate of elastic cartilage covered by thin skin
Meatus acusticus externus (ear canal)
The canal that extends from pinna to tympanic mem, covered by stratified squamous epithelium containing hair follicles, sebaceous glands, ceruminous glands
Middle ear
Tympanic mem, tympanic cavity, auditory ossicles
Continuous with auditory (Eustachian tube) which connects to nasopharynx
Auditory ossicles
Malleus (hammer), incus (anvil), stapes (stirrup)
Tympanic membrane
Separates external and middle ear at the base of the external auditory meatus (ear canal)
External surface of tympanic mem
Stratified squamous epithelium (like rest of external ear)
Internal surface of tympanic mem
Simple squamous epithelium, continuous with tympanic cavity
Hearing
Function cerebral cortex
Pinna
External cartilage
Temporal bone
Location of inner ear - hard to preserve for histology
Facial canal
Separated from middle ear by thin connective tissue + simple squamous epithelium. Facial nerve paralysis is common sequela following otitis media
Amplitude
Volume
Frequency
Pitch
Auditory reflex
Turning head in response to sound = brainstem reflex
Anotia
Growth disorder - absence of an ear
Microtia
Growth disorder - ear has not formed properly and is small compared to what would be considered normal for the individual/species.
Polyotia
Growth disorder - many (poly-) ears/pinnae
Other names for aural plaques/papillomas of the ear
Equine ear papillomas, papillary acanthoma, hyperplastic dermatitis of the ear, ear fungus
Aural haematoma
Blood vessel bursts within pinna, serosanguinous fluid formed haemorrhage distends the pinna and creates a cavity between the skin and cartilage of pinna
Pus
Formed by a vast array of neutrophils entering into an area the body recognises as being under attack from a bacterial pathogen.
Granulomatous response
Suspect mycobacteria spp. involvement
Mucoperiosteal exostoses
New bone growth - firm + bony protrusions, originate from mucoperiosteum of tympanic bulla
Dentigerous cyst / temporal odontomatas
Masses with an ectopic tooth or teeth in them and can swell and rupture through the skin, typically towards the base of the aural pinna
Dermoid cyst
Similar to dentigerous cyst without tooth present
Mammonongamus auris
Cat ear-worm
Acantholysis
Loss of coherence between epidermal desmosomes (adhere epidermal keratinocytes) due to the breakdown of intercellular bridges; separation of keratinocytes, seen in pemphigus foliaceous auto-immune disease
Guttural pouch tympany
Pouch filled with air
Guttural pouch empyema
Pus/suppuration in cavity
Presbycusis
Age-related deafness caused by arthritis between auditory ossicles so cannot transmit pressure waves sound into fluid waves in perilymph through vestibular window
