Gustation and Olfaction Flashcards
3 Types of lingual papillae
Circumvillate (line across back of tongue)
Foliate (scrunched group on side of tongue)
Fungiform (More in the front)
Areas of the taste bud
Sensory cells detect taste and imitate signal transduction. Nerve at the base.
Importance of saliva for tasting
Food must dissolve in saliva for taste to be detected by taste buds.
Modern taste receptor distribution and what tastes
taste modalities overlap in areas of the tongue.
Sour Sweet Salty Umami Bitter
Mechanism of action for tasting salt
Simplest mechanism through sodium channel. Results in depolarization.
Mechanism of action for tasting sour foods
Sour foods have high acid content. Hydrogen ions in acid block potassium channels, which causes depolarization
Mechanism of action for tasting sweet, bitter, and umami foods
G protein coupled receptors on the microvilli. Depolarization occurs this way.
Afferent information sending taste will synapse where in the thalamus
Thalamus Lateral-posterior division Ventral tier Posterior nucleus (ventral posterior nucleus) medial portion
projects to the primary somatosensory cortex
Taste receptors in the oropharynx is by which CN
10
Taste and sensory of the front of the tongue
Taste- 7
Sensory- V3
Taste and sensory of the back of the tongue
9 and 9
Olfactory uses which type of receptors
Chemoreceptors.
What makes up CN1
Axons of olfactory receptor cells that pass through the olfactory foramen within the cribriform plate of ethmoid, synapse in the olfactory bulb, and then project out to make up the olfactory tract.
The olfactory bulb projects out of the
Olfactory foramina of the cribriform plate of ethmoid.
Chemoreceptors of olfaction are embedded in which type of epithelial cells
Simple columnar
In order for chemoreceptors to detect odors,
Chemicals must be dissolved in water/lipid/mucous to be detected. They undergo rapid sensory adaptation.
Immature receptor cells are called
Basal cells.
Chemoreceptors can detect how many odorants
400 specific types, but up to millions due to multiple odorants
How are chemoreceptors depolarized
By G protein coupled receptors. Sets off cascade that opens ion channels and causes depolarization
What is the only sensory pathway that does not initially synapse in the thalamus
olfaction. Travels to the olfactory cortex before the thalamus. Synapses with the thalamus in the anterior lobe, where it projects to the cingulate gyrus to the limbic system/amygdala
How smells can trigger emotions and memories.
What lobe is the auditory, olfactory, and gustatory cortexes located at?
In the temporal lobe.
