Ch 8: chemical senses Flashcards
five special senses
smell, taste, vision, hearing, equilibrium
five tastes
salty, sweet, bitter, sour, umami
four organs of taste
tongue, palate, pharynx, epiglottis
papillae
protuberances on the tongue containing taste buds
vallate papillae
back of tongue, 100-300 buds/papilla
fungiform papillae
entire tongue, 5 buds/papilla
foliate papillae
lateral tongue, no taste buds
taste receptor cells
50-100 per taste bud
gustatory pathway
Gustatory receptor cells → cranial nerves (facial, glossopharyngeal, and vagus nerves) → gustatory nucleus (in medulla) → thalamus → primary gustatory complex (in insula)
labeled line hypothesis
Each taste receptor type responds to only one specific taste; connected by separate axons in the brain
population coding
The responses of a large number of broadly tuned neurons are used to specify the properties of a particular taste
olfactory epithelium cells
olfactory receptor cells, supporting cells, basal cells
supporting cells
provide physical support and nourishment
basal cells
produce olfactory receptor cells
olfactory nerve
made up of axons of olfactory receptor cells
which cranial nerve is NOT involved in conduction of nerve impulses associated with the sense of taste?
oculomotor (III) nerve
does the olfactory nerve directly project to the olfactory cortex?
no
olfactory tract
axons of mitral cells
olfactory population coding
each odor is represented by the activity of a large population of neurons
olfactory maps
neurons responsible to particular odors may be organized into spatial maps
olfactory temporal coding
the timing of action potentials may be an essential code for odors
olfactory nerve axons project to ___________ cells in the olfactory bulb
mitral
the olfactory bulb cells send axons to the _________________
olfactory cortex
