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21 Cards in this Set
- Front
- Back
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Functional Categories of Sensory Receptors:
a. Somatosensory receptors: -...: neuron with a “naked” free nerve ending. -more ...: neuron with nerve ending encapsulated in connective tissue b. Mechanosensitive receptors: respond to ... energy (changes in fluid movement) c. Chemoreceptors: respond to .... d. Photoreceptors: respond to .... e. Nociceptors: respond to .... |
simplest
complex mechanical chemicals light noxious stimuli |
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Sensory Transduction:
Either through specialized afferent neuron endings or separate cell closely associated with peripheral neuron ending Converts Stimulus into ... Then to ... if signal is above threshold |
graded potential
AP |
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Receptor Potentials:
Respond to stimuli with ... potentials (called receptor potentials or generator potentials) In most cases, response is a conventional ... (rarely, ...) Intensity of stimulation is coded for in terms of: - ... of action potentials generated -... of receptors activated (population coding) - ... of stimulus |
graded
EPSP IPSP Frequency Number Duration |
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Intensity & Duration of Stimulus:
Sustained stimulation leads to adaptation -... (ex. a cut) receptors do NOT adapt or adapt slowly -... (ex. taste and olfaction) receptors adapt rapidly |
Tonic
Phasic |
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In humans two major chemoreceptive senses are smell (...) and taste (...).
Taste and smell send information to phylogenetically old areas of the brain associated with memory and emotion. ... plays a vital role in food selection, sweet and umami are associated with nutritious food. ... tastes are associated with the possible presence of toxins and are usually avoided. |
olfaction
gustation Taste Bitter |
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Taste and smell are closely linked even though they involve different receptors and receptive processes. This may suggest an ... in central processing.
Olfactory stimulation by ... play an important role in reproduction. |
overlap
pheromones |
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Taste and smell also regulate ... secretions.*
Smell is .... |
gastrointestinal
directional |
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There are many different flavors that we can experience and tell apart. However, there are only 5 basic tastes:
... |
-sweet
-salty -bitter -sour -umami |
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look at slide 26 and 27
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ok
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Functions of taste:
provides an assessment of foods - necessary to differentiate between new sources of food and potential toxins: -... and ... - relate to aspects of homeostasis -... - high calorie foods -... - potentially toxic |
salty & sour
sweet bitter |
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some taste preferences are inborn:
-innate preference for ...- mothers milk -... substances rejected experience can modify taste preferences e.g. can learn to enjoy bitterness of coffee (except Starbucks) body has capacity to recognize deficiencies of key nutrients and induce an appetite for them e.g. if deprived of salt, may crave salty foods |
sweet
bitter |
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Gustation:
... types of papillae with taste buds Taste buds contain group of receptor & support cells |
3
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Papillae are taste sensitive structures.
They contain taste buds: ... papillae (mushrooms) -most anterior part of tongue (appear as red spots) -contain one to several taste buds each ... papillae (not common in humans) -edge of tongue, anterior to circumvallate line -contain multiple taste buds ... papillae -back of tongue on circumvallate line |
fungiform
foliate circumvallate |
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Taste receptor cells reside primarily in the ...; but also are in the soft palate, esophagus, epiglottis, larnyx in significant numbers
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tongue
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Receptor cells have apical ... (increased absorptive area) where most receptors/channels are located
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microvilli
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Each taste bud contains:
... cells - differentiate into new receptor cells. The receptor cells are continually renewed every 10-14 days (requires sensory nerve input) supporting cells afferent (sensory) nerves |
basal
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Innervation of taste buds:
oropharynx, epiglottis - ... posterior 1/3 - ... anterior 2/3 - ... |
10
9 7 (in chorda tympani) |
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look at slide 49
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ok
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...: Process by which a stimulus causes an electrical response in a cell.
Four mechanisms in taste: -Direct passage of a chemical through an ion channel (Na+, Ca2+, H+, K+). -Bind to and blocking ion channels. -Bind to and opening ion channels. -Bind to a membrane receptor and activates secondary messenger systems that in turn open or close ion channels (membrane receptors and G-proteins). |
Transduction
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Taste- transduction:
In all case the increased intracellular ... triggers transmitter release |
Ca2+
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look at slide 71-78
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ok
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