LECTURE 5- sensory receptors , pain science Flashcards
How many neurons pathways are there to the somatosensory cortex
3
what is the 1st order neuron
info from the sensory receptors to SC or BS
what is the 2nd order neuron
info betweeen SC or brain stem to thalamus
what is the 3rd order neuron
info from the thalamus to cerebral cortex
what is a receptor
converts stimulate energy into AP
what determines the type of receptors that are activated and pattern of signal transmission
stimulus
what is somatic senses
tactile, thermal pain , proprioception
what is visceral senses
conditions within internal organs
what are specialized senses
smell, taste, vision, hearing , balance and equilibrium
where are exteroceptor and what do they detect
at or near the body surface and detect external stimuli
where are interoceptors and what do they react to
deep and react to stimuli coming form internal body. organs (BH, blood pH)
examples of chemoreceptors
smell and taste
example of mechanoreceptors
touch
pressure
stretch
vitbratoin
what does each type of receptor have that are sensitive to stimuli that either damage or have potential to damage tissue
nociceptors
what are nociceptors
register pain
where are proprioceptors found
muscles , tendons , ligaments
what does tonic receptors detect and how do they adapt and how do they respond
detect object pressure and form
slow adapting
respond continuously as long as stimulus is present
what does phasic receptors adapt to , how do they adapt and what do they detect
adapte to continuous stimulus and then stop responding even if stimulus is present
fast adapting
detect motion, vibration , rate of change
what is the order of the peripheral sensory axons / afferents of decreasing diameter
la, lb, ll, lll, lV
where is there greater density of receptors
in distal body regions
what is considered to be superficial cutaneous receptors
meisners corpuscles (light touch , vibration)
merkel’s disk (pressure
what is in the subcutaneous cutaneous receptors
pacinian courpuscle
ruffinis ending
what are the 3 components of the sensory system
stimulus , receptors, conduction
what are the 4 attributes to condution
modality , location , intensity, duration
where are the 3 levels in the somatosensory system where signal processing for integration occur
receptor level
circuit level
perceptual leve
what is the speed of information processing determined by
axon diameter
amount of axon myelination
# of synapses in pathway
what is released when the AP goes above threshold
neurotransmitters
what circuit level processing is when synapses can spread action potentials to several areas of CNS
divergence
what is the convergence circuit level processing
synapses focus action potentials from several sensory neurons onto 1 narrowed area of CNS
what is perceptual level processing
sensory nerve tracts carry impulses to respective region of brain
What is a dermatome
skin area that is related to 1 spinal level
what is distal latency
time form stim to distal recording site
what is the pathology of peripheral nerve
neuropathy
what does nerve compression impact first and last
first - large myelinated axions and smaller nociceptive thermal and autonomic axons last
what can cause sensory ataxia
peripheral sensory nerves , dorsal roots, dorsal columns of SC or medial lemnisci
patients with _____ axatia will have similar motor performance eyes open/closed
cerebellar