Somatosensory System

Question 1

what are all sensations processed as in the nervous system?

Answer 1

electrical signals (action potentials)

Question 2

true or false – receptor cells are not always neurons

Answer 2

true

Question 3

how is the somatosensory system organized?

Answer 3

hierarchically

Question 4

what is ipsilateral projection?

Answer 4

sensed and processed on the same-side

Question 5

what is contralateral projection?

Answer 5

sensed and processed on the opposite side

Question 6

what is proprioception?

Answer 6

perception of body position

Question 7

what is nociception?

Answer 7

perception of pain

Question 8

what is pruiception?

Answer 8

perception of itch

Question 9

which major type of skin mechanoreceptors processes light touch?

Answer 9

merkel’s disk

Question 10

which major type of skin mechanoreceptors processes touch and slow vibrations?

Answer 10

meissner’s corpscles

Question 11

which major type of skin mechanoreceptors processes stretch, pressure, and warmth?

Answer 11

ruffini endings

Question 12

which major type of skin mechanoreceptors processes brief and rapid vibrations and deep pressure?

Answer 12

pacinian corpscles

Question 13

what is labeled line signal processing?

Answer 13

different qualities of touch are detected by different receptors and have different neural pathways to the brain.

Question 14

through which region can a sensory receptor detect stimuli to relay the info to the brain?

Answer 14

receptive field

Question 15

what will happen if primary neurons converge?

Answer 15

one large receptive field will be created and secondary neurons cannot be discriminated

Question 16

what will happen if primary neurons don’t converge?

Answer 16

small receptor fields will be created and secondary neurons can be discriminated

Question 17

where are neural cell bodies located?

Answer 17

in the dorsal root ganglion along the spinal cord

Question 18

how is information processed through the spinal cord?

Answer 18

1. info ascends ipsilaterally in the dorsal columns to the medulla (brainstem).
2. info crosses the midline.
3. travels to the somatosensory cortex through the thalamus.

Question 19

what are dermatomes?

Answer 19

areas of skin that are connected to a specific nerve on the spine

Question 20

where is touch information transmitted to?

Answer 20

ventral posterolateral nucleus (VPL) then to primary somatosensory cortex

Question 21

what is the somatosensory homunculus?

Answer 21

a body map that depicts the amount and location of where each part of the body is processed.

Question 22

which body parts have the largest representation in the somatosensory homunculus?

Answer 22

hands, face, and tongue

Question 23

what is the modulation of representation?

Answer 23

the size of somatosensory representation changes with use.