Physiology of Taste and Smell Flashcards
What type of receptors are those for taste and smell
chemoreceptors- stimulated by binding to particular chemicals
What influences taste perception
information from smell receptors
What is gustation
taste
What is the life span of a taste receptor cell
10 days
Where do taste receptor cells synpapse
with afferent nerve fibres
Where are taste buds present
the tongue
palate
epiglottis
pharynx
Where are the majority of tast buds
in papillae in the tongue (finger like projections on the dorsum of the tongue)
What are the four types of papillae in the human tongue and which is the most numerous
filliform -most numerous
fungiform
vallate
foliate
Where are signals conveyed to by the cranial nerves in response to a tastant
via the brainstem and thalamus to cortical gustatory areas
What are the five primary tastes
salty sour sweet bitter umami (meaty or savoury(
What stimulates each of the five tastes
salt- sodium chloride sour- hydrogen ions sweet- glucose bitter - diverse groups including poisons, alkaloids, toxins umami- amino acids esp. glutamate
What is ageusia
loss of taste function
What is hypogeusia
reduced taste
What is dysgeusia
distortion of taste
What is the science word for smell
olfaction
What three cells types are contained in olfactory mucosa
olfactory receptor cells
supporting vells
basal cells
What are olfactory receptors
specialised endings of renewable afferent neurons
What is contained in each neuron
thick short dendrite and an expanded end called an olfactory rod
what is an odorant
molecules that can be smelled
how long a life span do olfactory receptors have
2 months
Where do new olfactory cells come from
basal cells
How the afferent nerve fibres of the olfactory nerve get into the brain
pierce the cribriform plate of ethmoid bone and enter olfactory bulbs
How does sniffing enhance smekk
normally odorant only reach receptor by diffusion as they are above the normal path of airflow into the nose
sniffing draws air upwards enhancing the smell
What must a substance be in order to be smelled
sufficiently volatile
sufficiently water soluble
What is anosmia
inability to smell
What is hyposmia
reduced ability to smell
What is hyposmia an early sign of
parkinsons disease
What is dysosmia
altered sense of smell
