Flashcards in Lecture 36 - Chemical senses Deck (66):
What two things does flavor perception drive?
Olfactory, taste, and somatosensory cues
Where is the olfactory mucosa?
Roof of the nasal cavity
What is within the olfactory mucosa?
Mucus layer with odorant-binding proteins, olfactory, epithelium, underlying basal lamina (Bowman's gland)
What is mucus secreted from in the olfactory mucosa?
-- and --
What cell types are within the olfactory epithelium?
Olfactory receptor neurons
What is the function of the basal cells in the olfactory epithelium?
Stem cells; give rise to new receptors
What is the lifespan of the olfactory receptors?
What is the function of the supporting cells in the olfactory epithelium?
Columnar cells - contribute to mucus production
What kind of neuron are the olfactory receptor neurons?
What are the two regions of the olfactory bipolar neurons?
-- and --
basal unmyelinated axon
What is occurring at the dendritic end of the olfactory neurons?
Terminates in the olfactory vesicle
Protrude into the mucous layer and contain receptors
What happens at the basal end of the olfactory receptors?
Projects through the Cribriform plate with other axons as bundles (Olfactory fila)
What does the basal end of the olfactory receptor neurons synapse on?
Glomeruli of the olfactory bulb
How do the odorants in the air reach the olfactory receptor?
Cross the mucosa via binding to odorant binding proteins
How many odorant receptors does each olfactory receptor get?
What are the two transduction mechanisms that occur in olfactory transduction?
-- and --
What happens to the olfactory neuron when transduction occurs?
What is receptor cycling?
Once odorant receptor becomes saturated it retreats into the cell
What type of receptor is a olfactory receptor?
What type of system is the olfactory system? (in regards to how it works)
Change detector system - detects new odorants and ignores old ones
What is the central olfactory pathway? (basic)
Olfactory bulb - Tract - Cortex
How many layers are within the olfactory bulb?
What happens with the axons of the olfactory receptor?
Pass through the cribriform plate
Terminate in the olfactory bulb
What are the five layers of the olfactory bulb?
What is within the olfactory nerve layer?
AXONS of the olfactory receptor neurons
What is within the glomerular layer?
Synapses of olfactory receptor neurons on mitral and tufted cells
Tonography of odors
What types of neurons are periglomerular cells?
How are glomerular synapses organized?
Each synapse receives same odorant information
What synapses on the glomeruli after the olfactory receptors?
What is contained within the external plexiform layer?
Cell bodies of tufted cells
What is contained within the mitral layer?
Cell bodies of mitral cells
What are the three cell layers of the olfactory cortex?
Periamygdaloid - Piriform - Enorhinal
What is the path of olfactory information through the olfactory cortex?
anterior olfactory nucleus
What is the main output for the association fiber system?
What are other, besides lateral hippocampus, regions that the association fiber system projects to?
Ipsilateral olfactory bulb
Contralateral olfactory bulb/cortex
What projects to the hipocampus?
Lateral entorhinal cortex
What does the anterior olfactory nucleus project to?
Ipislateral/Contralateral olfactory bulb
What is important for feeding behavior?
Olfactory cortex projecting to the lateral hypothalamus
What is important for learning behavior?
Entorhinal cortex neurons projecting to the hippocampus
What is responsible for odor discrimination and identification?
Orbitofrontal cortex and insula
What also goes to the Orbitofrontal and insula?
What is disosmia?
Reduction/loss of sense of smell
What are three things that can cause disosmia?
What is the function of the vomeronasal organ?
Sexual activity - Flehman reaction - Emotional states - Illnesses
What are the three types of papillae on the tongue?
Vallate - Foliate - Fungiform
What part of the tongue do fungiform papillae cover?
What part of the tongue does the vallate papillae cover?
8-12 in V-shape on posterior tongue
Where are the foliate papillae?
one on each side of lateral tongue
What are the characteristics of a supertaster?
Higher density of fungiform papillae
Experience greater oral burn and oral touch
Supersniffers as well
Where are taste buds located?
What is the structure of a taste bud?
Taste pore - opening
Innervated by afferent neurons
What is the lifespan of a taste bud?
What part of the taste bud does the supporting cell make/
The outside portion
How many taste receptors to a taste bud?
What is the apical end of the taste bud covered in?
How does salty transduction occur?
Sodium of salt taste molecules may eneter through cation channels
What does sour transduction occur?
Protons of the sour taste molecules may block potassium channels
How is sweet, bitter, and sour tasted?
G protein coupled receptors
What is the central taste pathway for the anterior 2/3 of the tongue?
Fungiform/Foliate papillae - taste afferents - chorda tympani of facial nerve - geniculate ganglion - ipsilateral rostral solitary nucleus
What is the central taste pathway of the posterior 1/3 of the tongue?
Vallate papillae/Foliate papillae - taste afferent neurons - glossopharyngeal n. - Inferior ganglion of CN IX - ipsilateral rostral solitary tract
What is the central pathway for the soft palate?
Extralingual taste buds - taste afferent neurons - greater petrosal branch of the Facial N. - Geniculate ganglion - Ipsilateral rostral solitary nucleus
What is the central taste pathway for the epiglottis/esophagus?
Extralingual taste buds - taste afferent neurons - superior laryngeal br. of vagus n. - inferior ganglion of CN X - ipsilateral rostral solitary nucleus
What are the three ganglia involved with taste?
Geniculate - Petrosal - Nodose
What CN is the geniculate n. related to?
What CN is the petrosal ganglia related to?
CN IX - Glossopharyngeal