Lectures 9 & 10 (test 1) Flashcards
passive touch
placed in hand to feel, cannot move hands
active touch
can move hands to feel and manipulate the object
action for perception
characteristic movements of hands to identify an object
lateral movement
texture
pressure
hardness
static contact
temperature
unsupported holding
weight
enclosure
volume, global shape
contour following
exact shape
there is no _____________ for the sense of touch
static or stable egocentre
tactile agnosia
inability to identify objects by touch, caused by a lesion in the parietal lobe
peripheral neuropathy
is sensory loss due to damage or reorganization of peripheral nerves (a-alpha and a-beta), caused by infections, autoimmune diseases, genetics, alcoholism, tumors
peripheral neuropathy symptoms
- numbness
- stabbing pain
- burning pain
- sensitivity to touch
- coordination difficulties
- muscle weakness
- bladder / bowel problems
Ian Waterman
-relies of sight to know where limbs are
- falls to the ground if the light turned off
damage to the proprioceptive system below his neck
olfactory system
detect airborne chemicals
smell
gustatory system
detect chemicals dissolved in saliva
taste
chemical senses are different from other senses because…
- directly link to the limbic system
- 2 things can smell sweet but taste totally different
functions of chemical senses
- food selection
- warning system
- reproductive
- memories / comforting
odorants
volatile airborne chemicals
ortho-nasal olfaction
occurs when we sniff through the nostrils
retro-nasal olfaction
occurs when we inhale odorants in our mouth, they travel up back of the mouth to the upper nasal cavity
olfactory epithelium
- a sheet of compacted cells at top of the nasal cavity
- odorants must pass through protective mucus to reach cilia
what is the smell sense organ
olfactory epithelium
primary sensory smell neuron
cilia (bipolar)
how often are OSNs regenerated
every month or two
neural coding
the way that the identity, concentration and pleasurable values of odorants are represented in a pattern of APs relayed to the brain’s OSNs
labeled line coding
each fiber types codes a specific touch sensation
cross fiber coding
different qualities of a sensory modality are distinguished by a pattern of nerve discharges across a large population of fibers
Odorant receptors (ORs)
largest known gene family
~1000 OR genes in humans
combinatorial coding
look at the combination of activity and allow nervous system to respond to more stimuli
which nerve is ligand known for?
M71 OSN
incoming olfactory info converge onto ______-
glomeruli
unmyelinated axons from OSNs congregate into bundles and cribriform plate and arrive at the ______
olfactory bulb
odor image
the characteristic pattern of glomeruli activation for each odorant
juxtaglomerular cells
- encircle glomeruli
- act as excitatory and inhibitory interneurons
mitral and tufted cells
- serves as relay centers
- axons combine to form the olfactory tract which sends info to the piriform cortex
granule cells
- the deepest layer in olfactory bulb
- a network of inhibitory neurons
- integrate info from earlier layer to promote specific odorant identification
primary olfactory cortex
- also called piriform cortex
- 3 layered allocortex
at the junction of frontal and temporal lobes - mediate transmission between OBs
