Intro to Sensory Systems Flashcards
Examples of mechanoreceptors
encapsulated nerve endings in skin
hair cells in cochlea
examples of chemoreceptors
CO2 and O2 receptors
olfactory and taste receptor cells
receptor specificity
specific receptor is affected by only 1 type of stimulus
labels line principle
there is a chain of connected neurons from sensory receptor to the brain
frequency code
signal increasing stimulus strength by increasing frequency of nerve impulses
population code
signal increasing stimulus strength by increasing number of fibers activated
adaptation
when you keep hammering a receptor it starts reacting less
examples of non-adapting receptor
nociceptor
slowly adapting receptors (tonic receptors)
useful for giving continuous info about a stimulus
not useful for telling you an exact beginning or end
examples of slowly adapting receptors
Merkel cell ending, Merkel’s disce
Rapidly adapting receptors are also called
phasic receptors
rate receptors
examples of rapidly adapting receptors
Pacinian corpuscle
Meissner corpuscle
rapidly adapting receptors
useful for telling you an exact beginning and end
not useful for telling you continuous signal
can signal change in stimulus intensity
rapidly adapting receptors can help extract what type of information?
dynamic (velocity, acceleration)
what types of receptors are involved in tactile and vibratory sensation
free nerve endings
low threshold mechanoreceptors
funciton of free nerve ending
responsible for crude touch
what are low threshold mechanoreceptors
encapsulated endings of myelinated fibers
where are Merke;s disks found
base of epidermis
what has the highest spatial resolution of all sensory afferents
merkel disk
function of Merkcel’s disk
statis discrimination of shapes, edges and textures
function of slowly adapting afferent II
innervate a receptor that responds to stretching of skin
what is the fier from Meissner’s corpuscle
rapidly adapting
where are Meissner’s corpuscles found
closer to the skin surface than Merkel’s disc
what are Meissner’s corpuscles sensitive to
low frequency vibrations
what is responsible for detection of slippage between skin and an object held in hand
Meissner’s corpuslce
where are pacinian corpuscle found
subcutaneous tissue
which adapts more rapidly, meissner’s or pacinian corpuslces
pacinian
function of pacinian corpuscle
sensitive to high frequency vibrations
helps with skilled tool use
function of hair end-organ
detect movement of objects on body surface and initial contact of an object with the body
what receptors are involved in proproception
joint receptor
muscle spindle/golgi tendon organ
skin tactile receptor
what is the doral column responsible for
fine tactile discrimination, vibratory sense, and proprioceptive sense
2-point discrimination
lesions in dorsal column pathway can cause deficits in what
tactile discrimination
vibratory sense
proprioception
where does information of dorsal column cross
brainstem
what is the anterolateral system ( spinothalamic tract) responsible for
nociceptive and thermal sensation
where does informtion of anterolateral system cross
spinal cord
where is somatosensory cortex located
parietal lobe
what broadmann areas is primary somatic sensory cortex associated with
3b, 3a, 1 and 2
where is the foot area of somatotopic map found
medial cortex
what does cortical area of somatosensory cortex respond to
cutaneous stimuli
what do neurons in somatosensory area II do
show attention to modulated responses
nerve pressure palsy
limb falling asleep
sever one peripheral nerve would result in
sensory loss in gragments of adjacent dermatones
peripheral neuropathy would result in what
stocking glow pattern
which fiber types are myleinated (I - IV)
I, II, and III
A alpha function
axon of alpha motor neuron
muscle spindle primary ending (Ia)
golgi tendon organ afferent (Ib
A beta function
muscle spindle secondary ending (II)
axons of cutaneous mechanoreceptors
A gamma function
aon of gamma motor enuron to muscle spindle fibers
A delta function
fast pain
some temperature receptor
B function
sympathetic preganglionic axons
C function
slow pain, some temperature
sympathetic, postganglionic axons
which fiber types are mylinated (A- C)
A and B
conudtion velocity of A alpha
100 m/sec
conduction velocity of A beta
50 m/sec
conduction velocity of A delta
20 m/sec
conduction velocity of C
1 m/sec
adequate stimulus
the stimulus that affects 1 receptor, normally
conscious proprioception example
kinesthesia
