Olfaction and Taste Flashcards
There are 3 neurons involved in the olfaction pathway.
Neuron 1 is a ______ neuron, neuron 2 has its body in the __________ and it projects directly to olfactory cortices. Neuron 3 has its axon in the ___________.
bipolar, olfactory bulb, uncinate fasciculus
The lamina propria of olfactory mucosa contains ___________ which secrete mucus.
Bowman glands
Olfactory epithelium is __________.
It contains ___________ which provide metabolic and physical support to receptor cells, ________ cells that are proginator cells, and _________ cells which form synapses with CN V fibers and are sensitive to chemical irritants but are not discriminative.
pseudostratified columnar neuroepithelium, sustentacular supporting cells, basal cells (stem cells), microvillar (brush) cells
The basal cell nuclei of the olfactory epithelium is located close to the _________
lamina propria
olfactory receptor neurons are derived from the __________ and have ______ morphology
nasal (olfactory) placode, bipolar morphology
Olfactory receptor neurons are _________ and are covered by ensheathing cells
unmyelinated
Every olfactory receptor neuron has ___ type(s) of receptor for odorants
1
Odorant binding proteins are produced by the ________ cells
sustentacular
The cAMP-activated channels create _______ potentials when an odorant is detected
graded
a single odor can activate ______ odorant receptor(s)
multiple
______ odorant(s) can activate multiple glomeruli and this is referred to as ________
one, cross fiber activation
Cell bodies of periglomerular cells are in the ________ layer
glomerular layer
Tufted cells are found in the ______ layer
external plexiform layer
Mitral cells are found in the ______ layer
mitral cell layer
Granule cells are categorized as _______ and are in the _______ layer
interneurons, granule cell layer
sensory information from olfactory receptor neurons travels through the _______ and enters the ________.
From there it interacts with the ________ cells before being transferred to neurons of the _______ cells and _______ cells. Both of these cell types interact with ________ cells before passing their information onto the _______ tract.
cribiform plate, olfactory glomeruli, periglomerular cells, tufted cells, mitral cells, granule cells, lateral olfactory tract
The main efferent neurons of the olfactory bulb are ______ cells and _______ cells.
tufted cells, mitral cells
Granule cells lack _____
axons
centrifugal fibers provide excitatory input to ________ cells from the _________, ______, and ________.
granule cells, olfactory cortices, locus ceruleus, raphe nuclei
Centrifugal fibers provide feedback inhibition to _______ and _______ cells via __________ synapses
mitral, tufted, GABAergic dendrodendritics
Odorant binding proteins are produced by the ________ cells
sustentacular
The cAMP-activated channels create _______ potentials when an odorant is detected
graded
a single odor can activate ______ odorant receptor(s)
multiple
______ odorant(s) can activate multiple glomeruli and this is referred to as ________
one, cross fiber activation
Cell bodies of periglomerular cells are in the ________ layer
glomerular layer
Tufted cells are found in the ______ layer
external plexiform layer
Mitral cells are found in the ______ layer
mitral cell layer
Granule cells are categorized as _______ and are in the _______ layer
interneurons, granule cell layer
sensory information from olfactory receptor neurons travels through the _______ and enters the ________.
From there it interacts with the ________ cells before being transferred to neurons of the _______ cells and _______ cells. Both of these cell types interact with ________ cells before passing their information onto the _______ tract.
cribiform plate, olfactory glomeruli, periglomerular cells, tufted cells, mitral cells, granule cells, lateral olfactory tract
Granule cells lack _____
axons
centrifugal fibers provide excitatory input to ________ cells from the _________, ______, and ________.
granule cells, olfactory cortices, locus ceruleus, raphe nuclei
Centrifugal fibers send excitatory signals to ________ cells which provide feedback inhibition to _______ and _______ cells via __________ synapses
Granule cells, mitral, tufted, GABAergic dendrodendritic
Centrifugal fibers are _____ to granule cells and exit the olfactory cortices via the _______
Primary afferents, lateral olfactory tract/stria
Centrifugal fibers provide excitatory input to granule cells from _________, ______, and ________.
Primary olfactory cortices, locus ceruleus, raphe nuclei
Centrifugal fibers send excitatory information to granule cells which provide feedback inhibition via GABAergic synapses to _______ and ______ cells
Mitral cells, tufted cells
Odorant binding proteins are produced by the ________ cells
sustentacular
The cAMP-activated channels create _______ potentials when an odorant is detected
graded
a single odor can activate ______ odorant receptor(s)
multiple
______ odorant(s) can activate multiple glomeruli and this is referred to as ________
one, cross fiber activation
Cell bodies of periglomerular cells are in the ________ layer
glomerular layer
Tufted cells are found in the ______ layer
external plexiform layer
Mitral cells are found in the ______ layer
mitral cell layer
Granule cells are categorized as _______ and are in the _______ layer
interneurons, granule cell layer
sensory information from olfactory receptor neurons travels through the _______ and enters the ________.
From there it interacts with the ________ cells before being transferred to neurons of the _______ cells and _______ cells. Both of these cell types interact with ________ cells before passing their information onto the _______ tract.
cribiform plate, olfactory glomeruli, periglomerular cells, tufted cells, mitral cells, granule cells, lateral olfactory tract
The main efferent neurons of the olfactory bulb are ______ cells and _______ cells.
tufted cells, mitral cells
Granule cells lack _____
axons
Mitral and tufted cells receive inhibitory input from both _______ cells and _______ fibers.
periglomerular cells, centrifugal fibers
The axons of ______ and ________ form the lateral olfactory tract and stria
mitral, tufted
The __________ is the structure by which olfactory bulbs communicate
anterior commissure (medial olfactory striae)
_________ are secondary axons that branch from primary axons
Collateral axons (collaterals)
Mitral and tufted cells send collaterals to the ________ nucleus
anterior olfactory nucleus (within olfactory tract)
Olfactory cortices receive _______ connections with olfactory bulb
direct (secondary neurons)
The olfactory bulb sends direct connections to the following 4 cortices:
piriform cortex, anterior cortical amygdaloid nucleus, periamygdaloid cortex, lateral entorhinal cortex
The _______ cortex is the largest and is the major olfactory cortical area. It encodes higher order representations of odor quality, identity, and familiarity
piriform cortex
The ________ cortex is located in the most medial portion of the temporal lobe
piriform cortex
The olfactory cortices project to the ______, ________ nucleus, ______ cortex, and ________ cortex before projecting to the olfactory bulb via the centrifugal fibers
lateral hypothalamus, dorsomedial thalamic nucleus, insular cortex, orbital cortex
The ________ cortex is an olfactory cortex that preprocesses information that is entering the hippocampus
entorhinal cortex
The ________ cortex combines input from taste, texture, and smell and plays major role in flavor perception
orbitofrontal cortex
The orbitofrontal cortex is just anterolateral to the _______ and just lateral to the ________
optic chiasm, olfactory tract
The 3 efferent olfactory cortices are:
Ventral lateral thalamus, dorsomedial nucleus, orbitofrontal nucleus
The dorsomedial hypothalamic nucleus is located immediately adjacent to the _______
hypothalamus
Taste information is carried by a ________ primary neuron
pseudounipolar
The primary neuron cell bodies of the taste pathway are located in the _______ ganglion, _________ ganglion, and the _______ ganglion
inferior (petrosal) ganglion, geniculate ganglion, inferior (nodose) ganglion
Taste information in the posterior 1/3 of the tongue in the ______ and ______ papillae and continues in the ______ of CN ___ and synapses in the ______ ganglion
posterior foliate papillae, vallate papillae, lingual branches, CN IX, inferior (petrosal ganglion)
Taste information from the anterior 2/3 of the tongue begins in the _____ and ______ papillae before traveling via ______ of the CN ___ and synapses in the _____ ganglion
fungiform papillae, anterior foliate papillae, chorda tympani, CN VII, geniculate ganglion
Taste information from the extralingual taste buds of the soft palate travel via _____ to the ______ ganglion
CN VII, geniculate ganglion
Taste information to the epiglottis and esophagus travels via the ________ nerve of the CN ___ and synapses in the __________ ganglion
superior laryngeal nerve, CN X, inferior (nodose) ganglion
Papillae are formed by ________ epithelium
stratified squamous
taste buds on ______ papillae do not sit in pits, while taste buds in ______ papillae sit in pits which are in close proximity, and taste buds in _______ papillae sit in pits situated somewhat far from each other
fungiform papillae, foliate papillae, circumvallate papillae
Most of the tongue is covered in _____ papillae
fungiform papillae
Salty and sour tastants activate ________ taste receptors
ion channel
Sweet, umami, and bitter tastants activate ________ taste receptors
GPCR
____ taste receptors encode sweet and umami, _____ taste receptors encode bitter taste and both of these are expressed on different cells
T1R, T2R
Taste afferent fibers traveling in CN VII, CN IX, and CN X synapse in their respective ganglia and then project via the __________ to synapse in the ________ in the ______________
solitary tract, rostral solitary nucleus (gustatory nucleus), rostral posterolateral medulla
The ________ pathway is ipsilateral
gustatory
Gustatory pathway:
Neuron 1 has dendrites in the _______, cell body in the ______, ______, and ______ ganglia, axons in the _______ tract, and projects to the ________ nucleus directly adjacent to the vestibular nuclei and dorsal motor vagal nucleus.
taste buds, geniculate, petrosal, nodose, solitary tract, solitary nucleus
Gustatory pathway:
Neuron 2 has its cell body in the _______ nucleus, axon in the _______ tract in the _______ (CNS), and projects to the _________ of the thalamus
solitary nucleus, central tegmental tract, pons, ventral posteromedial nucleus of the thalamus
The central tegmental tract when it is in the pons is located adjacent to the __________
medial lemniscus
Gustatory pathway:
Neuron 3 has its cell body in the _______ nucleus of the thalamus, axons in the ________, and projects to the _______, _________, and _________.
ventral posteromedial nucleus of the thalamus, posterior limb of the internal capsule, insula, frontal operculum, postcentral gyrus
______ precedes the onset of Alzheimers, Parkinsons, and Huntingtons disease
smell disorder (anosmia)
olfactory hallucinations are also referred to as _______
uncinate fits
