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