Physiology Flashcards
(28 cards)
taste and smell receptors are what kind of receptors?
chemoreceptors
stimulation of taste and smell receptors induces what?
pleasurable or objectionale sensation
define gustation
act of tasting
sensory receptor cells of taste are arranged how?
mainly packaged in taste buds
what are the sense orgas of taste?
taste buds
taste buds consist of what?
sensory receptor cells and support cells
what is the life span of a taste receptor cell?
10 days
how are taste receptor cells replaced?
from basal cells within the taste buds
majoruty of tastebuds sit where?
papillae in tongue
what are the 4 type of papillae?
filliform
fungiform
vallate
foliate
what kind of papillae does not contain taste buds?
filliform
binding of tastant to receptor cells does what?
alters cell ionic channels producing depolarising receptor potential
receptor potential in tasting initiates what?
APs in afferent nerve fibres which synapse with receptor cells
what cranial nerves transfer info from tongue to brainstem?
ant 2/3rds- chorda tympani branch of facial
post 1/3rd- glossopharyngeal
what are the five primary tastes?
salty- NaCl
sour- H+
sweet- glucose configuration
bitter- tastants i.e alkaloids
umani (meaty/savoury)- amino acids especially glutamate
define ageusia
loss of taste
causes- nerve damage, inflamation, endocrine
define hypogeusia
reduced taste function
causes: chemo, meds
define dysgeusia
distortion of taste
casues- glossitis, gum infection, URTI, zic deficiency
define olfaction
act of smelling
what are the three cell types in olfactory mucosa?
olfactory receptor cells
supporting cells
basal cells
describe the neurones of olfactory receptors
thick short dendrite and an expanded end called olfactory rod
what is the life span of an olfactory receptor?
2 months
axons of olfactory receptors colectively form what?
afferetn fibres of olfactory nerve
what transmits smell information to the brain?
olfactory bulbs