Term
| How are the transduction mechanisms (how stimuli become graded receptor potentials) for taste & smell similar? |
|
Definition
| they are both coupled to G proteins |
|
|
Term
| How is the olfactory system different from other sensory systems in terms of sensory cell location/where they send their axons? |
|
Definition
sensory cells: located in the upper nasal cavity
axons: go directly to the olfactory bulb |
|
|
Term
| Do signals in the olfactory tract destined for the cerebral cortex get synaptically interrupted in the thalamus? |
|
Definition
| no! they go directly to the primary olfactory cortex in the medial temporal lobe near the uncus |
|
|
Term
| Where are taste receptor cells found? |
|
Definition
| in taste buds scattered over most of the tongue |
|
|
Term
| How many basic taste qualities do the sensory cells have receptors for? |
|
Definition
|
|
Term
| Where do signals from the taste buds go? |
|
Definition
| in the facial & glossopharyngeal nerves to the solitary nucleus in the upper medulla |
|
|
Term
| 3 parts of the brain that receive innervation from taste signals |
|
Definition
1. hypothalamus
2. amygdala
3. insula |
|
|
Term
|
Definition
| where integration of olfactory & gustatory information takes place |
|
|
Term
|
Definition
| the "olfactory brain"; in the early, primitive vertebrates almost the whole cerebrum was devoted to the processing of olfactory signals |
|
|
Term
|
Definition
| the mucous membrane of the upper part of the nasal cavity where the special receptor cells for smell are located |
|
|
Term
| What do the supporting cells do for the nasal receptor cells? |
|
Definition
| they insulate them electrically so that signals are not propagated from one cell to another |
|
|
Term
|
Definition
| cells that divide mitotically to give rise to nasal receptor cells |
|
|
Term
| What covers the dendrite ends of nasal receptor cells? |
|
Definition
|
|
Term
| Why is it significant that the cilia of nasal receptor cells are embedded in the mucus that covers the epithelium? |
|
Definition
| only substances dissolved in the mucus can act on the receptor cells |
|
|
Term
| stereochemical theory of smell |
|
Definition
| the receptor sites on the receptor cells have different shapes & only molecules with a complementary shape fit into the receptor site |
|
|
Term
What happens when a molecule binds to a specific odorant receptor protein
(OR) in the membrane of the cilia? |
|
Definition
|
|
Term
| Why do human ORs express (only) about 350 different ORs on the surface of the cilia, while rodents & lower primates express many more? |
|
Definition
| a large fraction of the human odorant-receptor genes are pseudogenes |
|
|
Term
|
Definition
| where the unmyelinated olfactory nerve fibers establish synaptic connections in the olfactory bulb; send their axons to the brain through the olfactory tract |
|
|
Term
|
Definition
| small, round aggregates in which mitral cells are collected |
|
|
Term
| How many zones differing with regard to receptor-gene expressions for smell exist in rodents? |
|
Definition
|
|
Term
| Do nasal receptor cells have use-dependent plasticity? |
|
Definition
|
|
Term
| 2 places where olfactory fibers terminate in the cortex |
|
Definition
1. periform cortex in the uncus
2. adjoining parts of the entorhinal area |
|
|
Term
| Where does the olfactory mediodorsal thalamic nucleus receive fibers from? |
|
Definition
|
|
Term
| 3 places where the orbitofrontal cortex receives projections from |
|
Definition
1. visual/somatosensory association areas
2. parts of the insula in receipt of taste information
3. areas related to emotions, motivation, & memory |
|
|
Term
|
Definition
| fibers that interconnect the olfactory nuclei on the two sides of the brain |
|
|
Term
| Why are olfactory connections (both direct & indirect via the amygdala) to the hypothalamus important? |
|
Definition
| eating & behavior directed at acquiring food |
|
|
Term
| Are sexual reflexes & sexually related behavior influenced by olfactory signals? |
|
Definition
|
|
Term
| Can olfactory sensations in certain sensitive period of development induce lasting changes of behavior (learning)? |
|
Definition
|
|
Term
| What neurotransmitter is required for signals from olfactory receptors to make a lasting synaptic change? |
|
Definition
|
|
Term
| Do signals from thermoreceptors & mechanoreceptors contribute to taste? |
|
Definition
|
|
Term
| What type of receptors are activated by spicy food in terms of taste perception? |
|
Definition
|
|
Term
| What type of receptors in the taste buds (primarily in the epithelium of the tongue) make up the true taste signals? |
|
Definition
|
|
Term
|
Definition
| small elevations of the mucous membrane of the tongue where taste buds are concentrated (they are also found along the lateral margins & root of the tongue) |
|
|
Term
| Where do the microvilli on the apical surface of the taste buds protrude? |
|
Definition
| into a small opening in the epithelium (the taste pore) |
|
|
Term
| What does ATP released from the basal aspect of the taste sensory cell bind to? |
|
Definition
| ionotropic purinoceptors (P2x) |
|
|
Term
| 4 elementary taste qualities |
|
Definition
1. salty
2. sour
3. sweet
4. bitter |
|
|
Term
| What is the fifth taste quality? |
|
Definition
|
|
Term
| 2 things detected by the taste receptors that evoke the umami quality |
|
Definition
1. amino acids
2. t-glutamate |
|
|
Term
| What is the order (tip of the tongue to the most posterior) of taste perception of the basic taste qualities? |
|
Definition
| sweet --> salty --> sour --> bitter |
|
|
Term
| Do fatty acids act on taste-cell ion channels? |
|
Definition
|
|
Term
| What is the difference in sensory perception of salty/sour VS sweet/bitter? |
|
Definition
salty/sour: depolarize taste cells by direct binding to ion channels
sweet/bitter: act mainly or only on G protein-coupled receptors |
|
|
Term
| How are the cells of the taste bud interconnected? |
|
Definition
| tight junctions that seal the lateral membranes off from the taste pore |
|
|
Term
|
Definition
| the family of G protein-coupled receptors what sweet & umami act on; also includes metabotropic glutamate receptors & GABA receptors |
|
|
Term
|
Definition
| a family of G protein-coupled receptors that bitter acts on |
|
|
Term
| Do signals from thermoreceptors & mechanoreceptors contribute to taste? |
|
Definition
|
|
Term
| What type of receptors are activated by spicy food in terms of taste perception? |
|
Definition
|
|
Term
| What type of receptors in the taste buds (primarily in the epithelium of the tongue) make up the true taste signals? |
|
Definition
|
|
Term
|
Definition
| small elevations of the mucous membrane of the tongue where taste buds are concentrated (they are also found along the lateral margins & root of the tongue) |
|
|
Term
| Where do the microvilli on the apical surface of the taste buds protrude? |
|
Definition
| into a small opening in the epithelium (the taste pore) |
|
|
Term
| What does ATP released from the basal aspect of the taste sensory cell bind to? |
|
Definition
| ionotropic purinoceptors (P2x) |
|
|
Term
| 4 elementary taste qualities |
|
Definition
1. salty
2. sour
3. sweet
4. bitter |
|
|
Term
| What is the fifth taste quality? |
|
Definition
|
|
Term
| 2 things detected by the taste receptors that evoke the umami quality |
|
Definition
1. amino acids
2. t-glutamate |
|
|
Term
| What is the order (tip of the tongue to the most posterior) of taste perception of the basic taste qualities? |
|
Definition
| sweet --> salty --> sour --> bitter |
|
|
Term
| Do fatty acids act on taste-cell ion channels? |
|
Definition
|
|
Term
| What is the difference in sensory perception of salty/sour VS sweet/bitter? |
|
Definition
salty/sour: depolarize taste cells by direct binding to ion channels
sweet/bitter: act mainly or only on G protein-coupled receptors |
|
|
Term
| How are the cells of the taste bud interconnected? |
|
Definition
| tight junctions that seal the lateral membranes off from the taste pore |
|
|
Term
|
Definition
| the family of G protein-coupled receptors what sweet & umami act on; also includes metabotropic glutamate receptors & GABA receptors |
|
|
Term
|
Definition
| a family of G protein-coupled receptors that bitter acts on |
|
|
Term
| 2 broad categories of primary taste afferents (based on the degree of specificity) |
|
Definition
1. specialists
2. generalists |
|
|
Term
|
Definition
| accompanying the facial nerve, contains the taste fibers from the anterior 2/3 of the tongue |
|
|
Term
|
Definition
| where the taste synaptic interruption in the thalamus occurs; a relay for signals from the face in general |
|
|
Term
| Where are taste signals transmitted from the thalamus to? |
|
Definition
| the face region of the SI, close to the representation of the tongue & the anterior part of the insula |
|
|
Term
| Does chemotropic localization exist in the primary taste area of primates? |
|
Definition
|
|
Term
| Are there "labeled lines" to keep apart signals from different kinds of taste receptors? |
|
Definition
|
|
Term
|
Definition
| taste discrimination occurs by simultaneous analysis of the activity pattern in many sensory units |
|
|
