Taste and Smell Flashcards
what types of receptors sense these
chemoreceptors —- detect chemicals in aq. solution
Olfactory bulb
interact with the olfactory epithelium that covers the superior nasal concha
—- neural projections of CN1
- pass through the olfactory foramina of cribiform plate
Connections between nose and CN
olfactory epithelium (includes receptor and supporting cells) : receptors detect shit via ciliary projections into the nasal mucosa, Basal cells —- make new cells
—- receptors have ciliary into the mucus and the axons pass through the cribiform plate + synapse with the mitral cell in the glomeruli
—— mitral axons leave as olfactory tract
Olfactory transduction process
bind to receptor via ciliary projections —- G couple mechanism
-binding activated Golf (causes it to be bound by GTP) - activate adenylate cyclase: converts ATP to cAMP
—- cAMP opens Na/Ca channels : depolarization of receptor and AP firing of receptor cell — synapse with mitral
Three types of papillae that have taste buds
Foliate papillae : R and L edges of tongue, have taste buds inside
Circumvallate papillae: back of the tongue, big bois
Fungiform papillae: front of the tongue; taste bud on the surface
Structure of taste buds
taste buds: are the actual sensors
- supporting cells: insulate receptor
- basal: give rise to new gustatory cells
- gustatory cells: taste cells
—- receptor at surface of pore — ligand binds and causes signal transduction — increase in Ca release from ER and from the outside
—- release neurotransmitter to primary sensory neuron
5 primary tastes and what the ligands are
sweet: sugar, saccharin, alcohol, AA
bitter; alkaloids
umami: glutamate
salt: metal ions
sour: H+
Gustatory pathway
CN VII and IX : carry impulses from taste buds to the solitary nucleus of the medulla —- project to thalamus — branch to gustatory cortex (taste) and hypothalamus/limbic
CN IX and X : back of tongue
VII: front 2/3 of tongue
