Cutaneous receptors & referred pain (3.4)

which body parts are the MOST sensitive? (large areas devoted to the touch perception and motor activity of the face)

lips, tongue, and hands , face

motor cortex is ______________ gyrus

motor cortex is *precentral* gyrus

in *referred pain*, 2 different regions share a common ___________________

nerve pain

amputees frequently report feelings of pain in their missing limbs as if they were still there

phantom limb phenomenon

sensory information from the cutaneous receptors projects to the _________________ gyrus (motor cortex) of the cerebral cortex

postcentral

receptors are not genralized throughout the skin but are clustered at different points

punctuate distribution

areas in which a receptor can be stimulated

receptive fields

damage to a visceral organ producing pain perceived at a different location on the body's surface

referred pain

the source of nerve stimulation is different from the perceived location of stimulus

referred pain

sense receptors respond strongly to acute changes in environment and the stop responding when stimuli becomes constant ex: smell of cologne or feel of clothing

sensory adaptation

with cutaneous receptors, where is the information integrated?

somatosensory cortex

somatosensory cortex is __________________ gyrus

somatosensory cortex is *postcentral* gyrus

sensations of pain adapt little T/F

true

the punctuate distribution is different for each of the sensory modalities (warmth, cold, touch, pain)? T/F

true

which body parts are the LEAST sensitive? (small area devoted to the touch perception and motor activity of the face)

trunk, hips, and legs

the density of touch receptors is measured by _____________

two-point threshold test

changes in texture; slow vibrations -dendrites encapsulated in connective tissue

Meissner's corpuscle

sustained touch and pressure -dendrites encapsulated in connective tissue

Merke'ls corpuscle

are pressure & sensations of itch and tickle part of cutaneous receptors modalities?

NO

deep pressure;fast vibrations -dendrites encapsulated by concentric lamellae of connective tissue

Pacinian corpuscle

sustained pressure -enlarged dendritic endings with open elongated capsule

Ruffini corpuscle (endings)

areas with more receptors take up more space on the somatosensory cortex? T/F?

True

direct stimulation of postcentral gyrus produces same sensations as those felt when the cutanous recpetors are stimulated T/F?

True

sensations of temperature are *NOT absolute* but relative to the baseline of sensory adaptation T/F?

True

tests the minimum distance 2 points can be perceived as separate

Two-point threshold test

transduce modalities into nerve impulses (action potentials) in sensory neurons---> somatosensory cortex (brain)

cutaneous receptors

___________________________ are more densely arranged in the face, tongue and hands than on the back and thighs and larger areas

cutaneous recpetors

light touch; hot and cold -Unmyelinated dendrites of sensory neurons

free nerve endings

what re the 4 modalities of cutaneous sensation?

warmth cold touch pain