DSA Olfaction and Gustation Flashcards
What might the Umami taste help ID?
amino acids
Where are olfactory receptors found for CN1
in olfactory mucosa of the superior portion of the nasal cavity
What houses odorant receptors?
non-motile cilia of the Olfactory receptor neuron–they are GPCRs (ligands)
What layer of the olfactory system holds many immune cells?
Lamina Propria (direct environment exposure)
What layer of the olfactory system turns over every 30-60 days?
Basal cells
What is activated once a ligand binds to the GPCR of an ORN?
Adenyl Cyclase–increase in cAMP—binds ion channels causing an inc Ca and Na influx—depolarization and AP
Describe the layers of the Olfactory Bulb?
Granule- granule cells (principle interneurons), regulation of other cells; release GABA
Mitral cell- bodies/axons of tufted cells-carry sensory info: receive aff signals from ORN of Glomerulus and then send off transmissions
External Plexiform- Dendrites of tufted, mitral, and granule cells–cross communication: granules interact with others via GABA with inhibits their activity
Glomerular- where aff info is transmitted form the environment; release GABA
Olfactory Nerve- axons of ORNs…. release Glutamate (excitatory)
What is the job of Centrifugal fibers?
Help regulate feedback loops–coming through the Anterior Commissure
What components make up the Olfactory Tract?
Lateral OT
cells of the Ant. Ol Nucleus
Fibers from Ant limb of the Ant. Commissure
What can stimulate Granule cells?
Centrifugal fibers—-causing a inh of Mitral and Tufted
Mitral and ORNs are antagonized by periglomerular cells—playing an important roll in ‘getting used to smells’
What receives afferent info from Lateral OT, and is mainly responsible for sending efferent info back to the bulb, then onward to other areas of the cortex?
The Anterior Olfactory nucleus
Where does the Olfactory cortex lie in the brain?
Paleocortex
What are the hippocampus and DM thalamic nucleus part of?
Neocortex- discrimination of id of odors
What does the oribtofrontal cortex do?
helps integrate olfaction, taste, and other food cues to help hemans experience flavor + enjoy food
What innervates the taste buds of thee soft palate?
Greater Superficial Petrosal N. (branch of CN7)
What do taste sensation fibers run to from CN7? and continue to?
Geniculate Gangila— to the Rostral Silitary Nucleus (Gustatory)
Name the synaptic path for Central Taste
synapse in Solitary—(ips Central Tegmental Tract) parvicellular Ventral Posteromedial Nucleus VPMpc— Frontal Operculum and Ant. Insular Cortex (still ips- Post. limb of IC)—Becomes “Rostral area of Brodmann 3b”(part of postcentral gyrus)
What part of the tongue would CN9 innervate? CN10?
Vallate papillae and Posterior Foliate papillae taste buds
tbs of epiglottis and esophagus
What is Ageusia?
complete taste loss
What is parageusia/dysgeusia?
alteration of the perception of taste (commonly from drugs)
What would nasal polyps cause?
hyposomia (non-cancerous)
What are the layers (major cells) of the olfactory epithelium?
lamina propria (immune cells)
basal cells (stem cells for ORN)
olfactory receptor neurons (dendrites in mucus & axons up to bulb)
support cells
brush cells (columnar ciliated cells)
mucus
What is essential for trapping of odorants?
mucus
Where is information from the environment transmitted to the olfactory bulb?
olfactory glomeruli
What is the result of odor information into lateral hypothalamus?
body responds w/ feeding behavior
What is the result of odor information into hhippocampus?
input linked to learning & behavior
What sense is not sent to the thalamus for primary processing?
smell !!!
What can a tumor in the internal acoustic meatus cause (aka vestibular schwanomma)?
loss of tase in ant 2/3 tongue if hits chorda tympani
ipsilateral facial paralysis
