Somatosensation (Chapter 5a)

Asomatognosia

Asomatognosia

________:: failure to recognize parts of ones own body- damage in the right posterior parietal cortex or premotor cortex.

Cognitive Evaluation

________:: thoughts on the pain, address it as decisions.

sports

Pain can be suppressed- ________ injuries, religious rituals, life- threatening situations.

Sense of touch neurons

________ are longest in the body- going from longest toe upward thru the spinal cord into the medulla at the brain stem and then to the thalamus.

Dermatomes

________:: a strip of skin innervated by a particular spinal nerve.

situational motivations

Motivational- Affective:: ________ and emotions.

Substance P

________:: further stimulates cells to promote action at the skin level.

Haptic sensation

________:: perception of fine touch and pressure.

Astereognosia

________:: inability to recognize objects by touch- focal cortical lesion at area SII, which integrates inputs from finger joints w /tactile info.

Nociception

________:: perception of pain and temp; free nerve endings.

Neurons

________ are activated- collaterals that come off and release Substance P.

Sensory transduction

________:: when a receptor cells converts the energy of a stimulus into action potentials.

Phantom limb pain

________:: some patients can be treated w /mirror image boxes and are more receptive to prosthesis b /c brain is still maintaining cortical space for the missing limb.

high sensitivity

Glabrous:: non- hairy skin; ________ (palms of hands, lips, tongues, soles of feet)

Pain fibers

________ release glutamate which goes up the spinal cord and signals the brain.

Substance P

Endorphins:: if enough endorphins are produced, ________ turns down= less pain.

Sensory transduction

when a receptor cells converts the energy of a stimulus into action potentials

Multiple specialized areas at multiple levels

interconnected by multiple parallel pathways

Think on a comparative level

how is there variation across species

Black fly, panther chameleon, American bald eagle

examples of ocular differences

Glabrous

non-hairy skin; high sensitivity (palms of hands, lips, tongues, soles of feet)

Glabrous skin

3mm

Hairy skin

2+cm

Nociception

perception of pain and temp; free nerve endings

Haptic sensation

perception of fine touch and pressure

Sense of touch neurons are longest in the body

going from longest toe upward thru the spinal cord into the medulla at the brain stem and then to the thalamus

Toe → medulla; medulla → thalamus (crisscrosses

if on right side, will move to left); thalamus → somatosensory cortex

Area of the medulla = decassation

criss-crosses

Dermatomes

a strip of skin innervated by a particular spinal nerve

Sensory-Discriminative

good pain vs. bad pain; where is the pain

Motivational-Affective

situational motivations and emotions

Cognitive-Evaluation

thoughts on the pain, address it as decisions

Adaptiveness of pain

pain is bad, but important for survival

Lack of clear cortical representation

remove SI and SII and we still perceive pain

Pain can be suppressed

sports injuries, religious rituals, life-threatening situations

Pain Pathways

Anterolateral System

A Delta fibers

large in diameter, myelinated axons, fast travel = sharp pain

C fibers

thin, unmyelinated axons, slow travel = dull or throbbing pain

Neurons are activated

collaterals that come off and release Substance P

Substance P

further stimulates cells to promote action at the skin level

Glutamate

mild pain

Substance P

intense pain

Endorphins

if enough endorphins are produced, Substance P turns down = less pain

Phantom limb pain

some patients can be treated w/mirror image boxes and are more receptive to prosthesis b/c brain is still maintaining cortical space for the missing limb

Naloxone

opioid antagonist

Methadone

opioid agonist