week 4 (haptics + olfactory) Flashcards
(15 cards)
question: what does threshold for detecting temp. change depend on?
- rate of change
- size of area being stimulated
⤷ larger area feels larger change - body location where stim. is made
explain: thermosensory adaptation (ex.)
ex. adapting to cold bucket
- after adapted -> dip in room temp water
- feels warm bc warm receptors are adapted to cold from before
- shifts physiological 0 to be colder so room temp feels warmer
(vv for adapting to warm)
explain: pathway for pleasant touch signals
- follow spinothalamic path
- but diverges at cortex
- CT fibers synapse in lamina II of dorsal horn
- second order neurons decussate and synapse in thalmus
- thalamus neurons projects to insula
⤷ links emo. to sensory
define: haptic percetion
- perceptual processing of inputs from multiple sensory subsystems
- active exploration = faster than passive touch when IDing objects
question: why is active exploration fast for IDing objects?
- given free manipulation of object
- idea that mind is willful and engages in purposeful exploration to get info it wants
question: are we good at haptic object recognition?
- good at 3D object recognition
- touch = good for texture and temp.
- vis. = good for simple geometry
question: how are curvatures perceived with haptics?
- slanted but all same height
- all same slant but diff. heights
- found that all same height but diff slants was perceived as curved
⤷ all same slants = perceived as flat - slant gives info about curvature
define: tactile agnosia
- inability to ID objects by touch
- cause by lesions in parietal lobe
question: orthonasal vs retronasal?
- ortho = through nostrils
- retro = through mouth
explain: olfactory neurons
- bipolar
- regen. by basal cells every 30 days
- respond to odourants dissolved in mucous
explain: olfactory pathway
- odourant binds to GPCR on olfactory neuron’s cilia
GPCR activates G-alpha to separate from G-betagamma - G-aloha activates adenylyl cyclase III
- adenylyl III makes cAMP
- cAMP brings and opens channels allowing Na+ and Ca2+
explain: processing info in olfactory bulb
- signals converge on glomeruli and dendrite of postsynaptic cells
- axons pierce cribriform plate and reach bulb
- form olfactory nerve
- ipsilateral
⤷ right side stays right
name + explain: cells in olfactory bulb (3)
1. juxta(peri)glomerular cells
- encircle glomeruli
- excitatory oor inhibitory
2. mitral and tufter cells
- relay centers
- axons combine to form olfactory tract -> sends into to primary olfactory cortex
3. granule cells
- deepest layer
- inhibitory neurons
define: primary olfactory cortex
- gets info from olfactory tract
- junction between frontal and temporal lobes
- does not pass thalamus
- contacts amygdala (emo.() and entorhinal cortex (goes to hippocampus = memory)
- anterior olfactory nucleus mediates transmissions from bulb to bulb
define: secondary olfactory cortex
