ENT physiology Flashcards
What is the function of the eustachian tube?
Ventilation pathway for middle ear mucosa (allows oxygen into cells)
What is the relationship between the oval & round window?
A one goes in the other moves out
What is the function of the hair cells in the ear?
Transduction (convesrion of mechanical ‘bending force’ into electrical impulse
What generates the AP of cells in the ear?
Stereocilia deflected towards longest causing depolarisation
What are the 5 key vestibular ‘end organs’?
Urticle
Sacculae
Lateral, posterior & superior semicircular canals
What are the maculae of the utricle & sacculae termed?
Otolith organs
What is the function of the otolith organs?
Perception of linear motion (firing stops so you know that the movement has stopped)
How do the semicircular cancals relate with each other?
At 90 degree angles
What is the vestibuloclear reflex?
A head turns in one direction the liquid pushes against the cochlea and this causes an increase in firing rate and the opposing side has a decrease in firing rate
What is seen if there is an issue with the vestibulo-ocular reflex?
Spontaneous nystagmus *flicking of eye back as brain is trying to focus)
What is a vestibular schwannoma?
Tumour of VII nerve sheath (schwann) cells
What kind of receptors are the receptors for taste & smell?
Chemoreceptors
Where are the sensory receptor cells of taste mainly found?
Taste buds
What is the life span of a taste receptor cell?
About 10 days
What are the 4 types of papillae on the tongie?
Filiform
Fungiform
Vallate
Foliate
Which nerve supplies the taste buds of the anterior 2/3rds of the tongue?
Facial nerve
Which nerve supplies the taste buds on the posterior 1/3rd of the tongue?
Glossopharyngeal
What are the 5 primary tastes?
Salty Sour Sweet Bitter Umami
What is ageusia?
Loss of taste function
What can cause ageusia?
Nerve damage Local inflammation (glossitis, radiation, tobacco) Some endocrine disorders (diabetes, cushings)
What is hyogeusia?
Reduced taste function
Causes of hypogeusia?
Chemo & medication
What is dysgeusia?
Distortion of taste function
Causes of dysgeusia?
Glossitis Gum infections Tooth decay Reflux URTI Medications Neoplasms Chemo Zinc deficiency
