chapter 14 Flashcards
(39 cards)
touch
sensations caused by mechanical stimulation of the skin, muscles, tendons, and joints
5 sensations of touch
tactile
pain
temperature
kinesthesia
propriosection
types of touch receptors
tactile
kinesthetic
thermoreceptors
nocireceptors
mechanoreceptors
sensory receptor that responds to mechanical stimulation like pressure, vibration, or movement
4 types of mechanoreceptors in the skin
messier corpuscle
Merkel cell neuritis complex
Ruffini ending
pacinian corpuscle
2 properties of mechnorecpetors
size of receptive field and rate of adaptation
fast adapting
respond when skin is first
stimulated and when stimulation is removed. not
between onset and offset of stimulation
slow adapting
remain active through the period
during which the stimulus is in contact with its receptive
field
slow adapting type 1 merkel
sustained pressure at low frequency
ex: reading brail or feeling the head of a screw
slow adapting type 2 ruffin
sustained downward pressure
ex: reaching for a coffee cup
fast adapting type I meissner
low fq vibrations of 5-50
ex: objects falling from our grip
fast adapting type ii pacinian
high fq of 50-700
ex: mosquito on skin
inner fibers/ intrafusal fibers
detect whether a muscle is expanded or contracted
nociceptors
a sensory receptor that responds to
tissue damage caused by extreme
pressure or temperatures
Examples: getting a papercut on your finger, extreme skin temperatures (<59°F or >113°F), internal organ damage
ThermoTRP ion channels
connected nociceptors
and themroreceptors to give us illusory sensation of
temperature and/or pain.
Endogenous/exogenous
opiates
block the neurotransmitters necessary to send the pain signal to the brain
Anti-inflammatory
top the
nociceptors from firing by
reducing fever or
inflammation (e.g., ibuprofen)
Congenital analgesia
no pain
somatosensory cortex
it has an orderly spatial organization (somatotopic)
it has systemic distortions in representation
the primary somatosensory
receiving area in the brain
analogous to primary visual
cortex (V1)
wilder penfield
determined no anesthesia during brain surgery
phantom limb
When the arm is amputated neurons in the face region invade the unused arm region
Ramachandran (1993)
Systematically stimulates regions
of the face using a cotton swab, different regions of the face
lawfully correspond to different
sensations in the amputated arm
ex: Upper lip = index finger
2 point touch threshold
the minimum distance at which two touch stimuli are perceptible as separated
humans are what
micro somatic