Pain and Touch Flashcards
A stimulus to the receptor produces a _____.
graded potential
If the graded potential generated by a stimulus is large enough, the receptor generates an _____.
action potential
Patterns of action potentials are _____ in a sensory system.
coded
A single neuron can convey stimulus intensity by changing the _____ of its action potentials.
frequency
Multiple neurons can act in _____ to strengthen the stimulus.
unison
as the stimulus strengthens, more neurons are recruited
Different neurons respond to different ranges of _____.
intensity
Range fractionation
different cells have different thresholds for firing, over a range of stimulus intensities
The _____ system detects touch and pain.
somatosensory
The four touch receptor classes are _____, _____, _____, and _____.
pain, touch, vibration, stretch
Free nerve endings reside in the _____ and respond to _____ and _____.
epidermis, pain, temperature
Merkel’s discs reside in the _____ and respond to _____.
epidermis, touch
Meissner’s corpuscles reside in the _____ and respond to _____.
dermis, touch
Pancinian corpuscles reside in the _____ and respond to _____.
dermis, vibration
Ruffini’s endings reside in the _____ and respond to _____.
dermis, stretch
Temperature receptors use the _____ pathway.
pain
Small _____ C fibers respond to _____ and _____.
unmyelinated, dull pain, low temperatures
_____ A-delta fibers respond to _____ and _____.
Myelinated, sharp pain, high temperatures
Capsaicin activates _____ via TRVP1 and is a _____.
C fibers, neurotoxin
Pancinian corpuscles run through _____.
dorsal root ganglia
A dorsal root ganglion is comprised of _____.
unipolar cells
Tonic receptors _____ action potential frequency.
gradually decrease
Phasic receptors _____ action potential frequency.
quickly decrease
Receptive fields contain the property of _____.
a single neuron
Receptive fields differ in _____ and _____.
size, shape
Most sensory pathways pass through the _____ and end in the _____.
thalamus, cerebral cortex
the somatosensory cortex _____ after amputation of a hand.
reorganizes
substance P is a _____ essential to responding to _____.
neurotransmitter, pain
Congenital insensitivity to pain is caused by inherited _____ in pain fibers in _____.
mutated sodium channels, dorsal root ganglia
Man on fire syndrome is cause by congenital _____ to pain.
hypersenstivity
The spinothalamic system transmits _____ and _____.
pain, temperature
Periaqueductal gray in the _____ is involved in _____.
midbrain, pain perception
C fiber gates can be closed by increased activity in _____.
A fibers
_____ delivers electrical pulses to the skin.
Transcutaneous electrical nerve stimulation (TENS)
Neurogenic pain
pain resulting from damage to nerves
Psychogenic pain
pain not due to disease, injury or any visible damage
Reflex Sympathetic Dystrophy results in _____, _____ (stage 1), _____, _____, and _____ (stage 2)
increased sensitivity of skin to touch (stage 1) localized swelling Swelling tends to spread (stage 2) Hair and nails become brittle Muscle wasting begins
Neurogenic pain is due to _____ of pain by neurons
inappropriate signaling
Postsynaptic spinal cord neurons take up _____, released during _____, and remodel their _____.
substance P, pain, dendrites
_____ of sympathetic input leads to dorsal horn neurons becoming _____: Increased spontaneous activity and response to all touch.
Overactivity, hyperexcitable
Patients with chronic pain have overactive _____ at rest.
somatosensory cortex
Sensory Integration Disorder results in stimulus _____ and _____.
avoiders, seekers
Synesthesia
a stimulus in one modality creates a sensation in another
this food tastes blue
Synesthesia results from _____, _____, or _____.
LSD
posterior temporal lobe seizure
result of blindness or deafness
Pain is ultimately processed in the _____.
singulate gyrus
The somatosensory cortex composed of half _____ and half _____ receptors.
Tonic, Phasic
_____ is the ability to sense orientation, location, and position of body parts.
Proprioception
