ear pbl Flashcards
location of the palatine tonsils?
Located at the posterior , inferior margin of the oral cavity
what is the location of the tubal tonsil?
located in the nasopharynx , posterior to the eustachian tube.
Where are lingual tonsils located ?
lie deep to the mucous epithelium covering the base (pharyngeal portion) of the tongue
A single pharyngeal tonsil (adenoid) is located where?
lies in the posterior superior wall of the nasopharynx .
What is Waldeyer’s ring
An interrupted circle of protective lymphoid tissue
In tonsils what does efferent lymphoid vessels do?
drainage so that activated lymphocytes from the tonsils to other lymphoid organs.
function of the tonsils?
First line of defence against ingested or inhaled foreign pathogens, by trapping bacteria/viruses.
They are important in activating the immune system, especially in producing antibodies that prevent lung/ throat infections.
What epithelium lines the tympanic membrane ?
Is converted by epidermis and lined by Simple cuboidal epithelium
What are ceruminous glands ?
Specialised sweat glands in the external auditory canal that secretes cerumen which helps prevent dust and foreign objects from entering the ear
What does the stapedius do?
Supplied by the facial nerve , it is the smallest skeletal muscle that dampens large vibrations of stapes due to loud noises - protects the oval window and decreases sensitivity of hearing
What is the tensor tympani
Innervated by the mandibular branch of the the CN V
Limits the movement and increases the tension on the eardrum to prevent damange to the inner ear from loud noises
what are the two divisions of the inner ear
outer bony labryinth
and inner membranous labyrinth
what is the bony labryinth
a series of cavities in the petrous portion of the temporal bone divided into 3 areas.
semi cicular canals
vestibule
cochlea
what is membranous labyrinth
a series of epithelial sacs and tubes within the bony labryinth that have the same general form as the bony, and contain receptors for hearing and equilibrium
where does the scala vestibuli end
the oval window
where does the scala tympani end
the round window
whatis the bony labryinth filled with
perilymph
what is the helicotrema
part of the cochlear labryinth where the scala tympani and the scala vestibuli meet. the hair cells near this area best detect low frequency sounds
pathophysiology of otitis media
tubal tonsils hypertrophy in response to infection which blocks the opening of the auditory tube , new air cannot gain access to the middle ear . middle ear is lined with respiratory epithelium and also contains mucus secreting goblet cells, so the mucus builds up in the middle ear
what is acute otitis media
refers to an acute middle ear infection which has abrupt onset of signs and symptoms related to middle ear inflammation and effusion
WHAT is otitis media with effusion
refers to presence of fluid in the middle ear without signs and symptoms of AOM and may occur spontaneously due to poor eustachain tube function or as an inflammatory response following AOM
what is conductive hearing loss
occurs usually in the external and middle ear .
interference of the ability of sound to be transmitted to the inner ear
sensorineural hearing loss
occurs in the inner ear (sensory) or auditory nerve/auditory pathway (neural)
many sensorineural hearing losses are permanent because the inner ear and hair cells have only limited ability to repair themselves
what is Rinne’s test
o Tuning fork is placed on the mastoid bone (bone conduction) and then
placed next to the external ear (air conduction)
o Usually air conduction is heard louder than bone conduction ->
positive Rinne’s test
o If bone conduction is louder than air conduction ->negative Rinne’s
test and indicates conductive hearing loss in that ear
what is weber’s test
o Tuning fork is placed on the forehead
o Patient is asked in which ear the sound is louder
o If the patient hears the sound equally in each ear or cannot localise ->
normal and termed a mid-line Weber’s
o Weber’s lateralises towards a conductive hearing loss and away from a
sensironeural hearing loss
o For example, if the patient hears the sound louder in the right ear -> indicative of either a right conductive or left sensironeural hearing loss
what are grommets
performed under general anaesthetic . a small ventilation tube is inserted into the childs ear through a small incision in the eardrum which helps to drain away fluid in the middle ear and maintain air pressure in the middle ear . majority of grommets fall ut after 6-15 months
4 ways hearing loss affects children
causes delay in the development of receptive and expressive communication skills
language deficit causes learning problems that result in reduced academic achievement
communication difficulties often lead to social isolation and poor self-concept
may have impact on vocational choices
what screening tests are available for new borns
4-5 weeks of birth, first offered is Automated Otoacoustic Emission (AOAE) test. involves placing a soft tipped probe into baby’s ears and playing sounds and trying to detect a response from baby’-s cochlea .
babies who do not have a response are referred for a Automated Auditory Brainstem Response test.
involves playing sounds to the baby to try and detect responses from their brainstem via electrodes placed on the baby’s head and neck. measures not only the integrity of the baby’s inner ear but also the auditory pathway . it can therefore detect the rare condition of auditory neuropathy in children who are deaf but have normal oto-acoustic emissions.
what is the glottis
the opening of the top of the pharynx which is covered by the epiglottis when swallowing
what is the aryepiglottic fold
triangular opening at the entrance of the larynx that is narrowed at the front , wide behind and sloping obliquely downward and backward
cricoid cartilage
the cartilage ring below the thyroid cartilage and just above the thyroid gland
piriform fossa
a small pouch or recess in the laryngopharynx whihc is a common place where small things get stuck
