EX1; Sensory Physiology Flashcards
Unique experience associated with a particular modality beings where
at a receptor
Initial interaction of stimulus with receptor is this; transformation of physical energy into neural signal
transduction
The type of energy that a given receptor type is most sensitive to is called what
adequate stimulus
Sensory specificity is due to what
limited sensitive range of a receptor
This law states that central connections determine modality like; stimulation of optic nerve bypassing receptors - light, stimulation of auditory nerve bypassing receptor - sound
Law of Specific Nerve Energies
What are the 5 types of sensory receptors
mechanoreceptors thermoreceptors photoreceptors chemoreceptors nociceptors
Somatosensory uses what types of sensory receptors
mechano
thermo
chemo
noci
Olfaction and taste uses what type of sensory receptor
chemo
Vision uses what type of sensory receptor
photo
Audition and balance uses what type of sensory receptor
mechano
A physical (direct) interaction of stimulus with membrane protein opens up what
ion channels; somatosensory, vestibular, auditory, taste
A molecular interaction of stimulus with a membrane proteins involves what
G-protein; vision, taste, olfaction
What are the three steps of direct transduction in the taste system
- Na enters through epithelial Na channels
- action potentials lead to Ca entry
- release of ATP as neurotransmitter
What are the three steps of molecular G-protein couples transduction for “sweet” stimuli
- sugars bind to receptor coupled G-protien
- release of intracellular Ca activates TRPm5 channel (transient receptor potential)
- depolarization leads to action potentials and release of neurotransmitter ATP
This is a family of ion channels first found in Drosophila comprised of 6 transmembrane domains with a channel between the 5th and 6th
transient receptor potentials channels (TRP)
Which ion do TRP channels pass with a large variety of activating mechanisms
Ca
What 7 things can open different TRP channels
intracellular Ca temperature chemicals sounds light pH and osmolarity mechanical
The increase of these three things codes for intensity
increase in stimulus intensity
increase in receptor potential
increase in # of action potentials
The relationship between stimulus intensity and neural and perceptual responses is sometimes what
linear
This is not a precise value (statistical concept)
threshold
What is the function of sensitivity of receptors
require a stimulus level that produces an action potential
Threshold is not only a function of the stimulus, it can also be affected by what
psychological, neurological, or pharmacological factors
can be useful diagnostic tool
This is what a receptor (or neuron) is sensitive to
receptive field; smaller would be more finer and spatially limited
True or False
There is across neuron coding for olfactory quality
True; comparing activity across olfactory fibers provides a more or less infinite number of patterns