Somatosensory System (3)

Question 1

what is the difference between glabrous and hairy skin

Answer 1

glabrous skin is hairless and has more receptors than hairy skin

Question 2

what are the two main groups of somatic sensory receptors and where are they located

Answer 2

mechanoreceptors: responds to stimuli other than pain/temperature in the skin
nociceptors: responds to pain/temperature; also in the skin

Question 3

what are mechanoreceptors sensitive to

Answer 3

bending/stretching of the skin

Question 4

what are the two different somatosensory receptive fields

Answer 4

meissners corpuscles: small receptive field

pacinian corpuscles: large receptive field

Question 5

what is somatosensory adaptation and how is it obtained

Answer 5

if a receptor adapts quickly, they will respond to only onset and offset stimuli
if a receptor adapts slowly, they will continue to respond to the stimuli throughout the entire stimulus

Question 6

describe Aalpha receptors

Answer 6

proprioceptors, fastest conduction velocity, myelinated

Question 7

describe Abeta receptors

Answer 7

mechanoreceptors, mid conduction velocity, myelinated

Question 8

describe Adelta receptors

Answer 8

nociceptors, mid conduction velocity, myelinated

Question 9

describe C receptors

Answer 9

nociceptors, slowest conduction velocity, not myelinated

Question 10

what is the dermatone

Answer 10

the spinal cord of afferent innervation; cervical, thoracic, lumbar, sacral, determines which vertebrae each section of the body sends information to

Question 11

describe the hapsis pathway!!

Answer 11

1. dorsal root axon
2. dorsal column
3. dorsal column nuclei
   (crosses to other side in brainstem/medulla)
4. medial lemniscus
5. thalamus
6. cerebral cortex

Question 12

describe the nociception pathway!!

Answer 12

1. dorsal root axon
(crosses to the other side in spinal cord)
2. lateral spinothalamic tract
3. thalamus
4. cerebral cortex

Question 13

what sense can bypass the thalamus

Answer 13

smell

Question 14

what is the somatosensory homunculus

Answer 14

every part of the body takes up a different amount of the brain; more neurons/brain is devoted to globous skin

Question 15

what are nociceptors

Answer 15

receptors associated with pain and temperature

Question 16

what is hyperalgesia

Answer 16

when the body is more sensitive to stimuli around an injured part of the body

Question 17

describe referred pain

Answer 17

substantia gelatinosa neurons receive pain input from the skin in one area as well as an internal organ so the brain registers pain in both areas

Question 18

what is the gate theory of pain (who is credited for it)

Answer 18

melzack and wall

hapsis input can inhibit pain input

Question 19

what is descending innervation

Answer 19

serotonin and endorphin reduce pain chemically

Question 20

what are the hot and cold receptors

Answer 20

hot: capsin
cold: methanol

Question 21

true or false: thermoreceptors have static responses

Answer 21

falso