Lecture 41: Neuroanatomy of the Chemical Senses Flashcards
What are supporting or sustentacular cells
Columnar cells which contribute to mucus
What are basal cells in olfactory epithelium
Stem cells which give rise to new olfactory neurons with lifespan of 30-60 days
What are the apical dendrites
Dendrites that terminate in the olfactory vesicle with 10-30 no motile cilia that produce into mucus layer and contain odorant receptors
What axons project through cribs form plate with other axons as bundles called olfactory fila that synapse in the glomeruli of the olfactory bulb
Basal unmyelinated axons
Air is exhaled through ___so it doesn’t dilute the scent of incoming air
Side slits
Olfactory transduction uses what kind of receptors
GPCR
Odorant molecules interact with what proteins to cross mucus layer
Odorant binding proteins
Only one type of odorant receptor per ____ neuron
Olfactory receptor neuron
Odorant molecules bind to odorant receptors on ___ of olfactory receptor neurons where transduction occurs
Cilia
What are the two transduction mechanisms for olfaction
Cation and calcium
(Both led to olfactory depolarization)
T/F: odor compounds can combine to stimulate various odorant receptors with variable activations. Perceptions of smell rely on relative strength of activation combinations
T
Explain why we get used to smells
Olfaction is a change detector system so when odorant receptors are saturated they will undergo receptor cycling and odorant molecule is unbound from receptor
Benefit is we filter out background odors to detect new ones
What are the 5 layers of the olfactory bulb
- Olfactory sensory neurons (olfactory epithelium)
- Periglomerular cells (glomeruli)
- Tufted cells (glomeruli)
- Mitral cells (olfactory bulb)
- Granule cells (olfactory bulb)
Each glomerulus synapses with olfactory neurons that all produce the ___type of odorant receptor
Same
CN I carries olfactory information back to what part of the brain
Piriform lobe
What part of cortex receives olfaction
Olfactory cortex
What part of cortex receives olfaction and taste
Orbitofrontal
What part of cortex receives taste
Insula
Olfactory neurons that project to ____ affect feeding behavior and appetite
Hypothalamus
Entorhinal cortex neurons that project to ___ affect learning and learned repsonses
Hippocampus
Amygdala projections contribute to ___responses
Emotion
What organ is involved in sexual activity, particular the lip curl reaction demonstrated by male animals aroused by odor of vaginal secretion or urine from estrous females
Vomeronasal organ
What are the 5 tastes
Sweet, sour, salty, bitter and umami
T/F: specific taste buds are regionally located
False- all tastes buds are distributed across tongue
What papillae are on the rostral 2/3 of tongue
Fungiform papillae
What papillae are on caudal tongue
Vallate papillae
Where are the foliate papillae located
1 on each side
Taste buds are located on the ___
Tongue papillae
T/F: taste buds are innervated by multiple neurons
T
What cells form outer envelope of bud
Supporting cells
What cells give rise to new taste receptor within 10-14 days
Basal stem cells
What covers the end of each taste bud
Microvilli
What tastes directly interact with specific ion channels to depolarize
Salty and sour
What taste has their protons block potassium channels
Sour
What tastes use GPCR’s to initiate depolarization
Sweet, sour, bitter
What is the only taste penguins have
Salty, sour
What tastes do cats lack
Sweet
What are the three sensory taste nerves
- Chorda tympani (VII)
- Glosspharyngeal (IX)
- Vagus (X)
What nerve provides taste to epiglottis
Vagus
What nerve provides taste to caudal 1/3 of tongue
Glossopharyngeal
What nerve provides taste to rostral 2/3 of tongue
Chorda tympani
All taste sensations from VII, IX and V are transmitted to ___ nucleus and tract in ____
Solitary nucleus and tract in brainstem
