somatosensory

Question 1

the body senses

Answer 1

1. touch
2. thermoception
3. nociception
4. proprioception / kinaesthesis

Question 2

tactile perception

Answer 2

perception that results fro, the mechanical deformation of the skin

Question 3

how are tactile receptors classified

Answer 3

1. the type of stimulation they respond to
2. the size of their rf
3. speed of adaptation

Question 4

where are the tactile receptors located

Answer 4

in the dermis and epidermis
- epidermis: the most surface layer

Question 5

mechanoreceptors

Answer 5

respond to mechanical stimulation like pressure vibration and movement

Question 6

4 types of mechanoreceptors

Answer 6

1. SAI (markelle)
2. SAII
3. FAI (Meissner)
4. FAII (Pacinian)

Question 7

Type 1 vs type 2 receptors

Answer 7

type one have smaller receptive fields which give them higher acuity/spatial resolution
- type 1 are usually closer to the surface

Question 8

slow adapting vs fast adapting receptors

Answer 8

• slow adapting will fire continously as they are stimulated
• fast will fire when they start and end
• fast has better temporal

Question 9

SAI

Answer 9

• markelle cells
• dense in the dermis
• high spatial acuity and low temporal variation
• respond to indentation, curves and textures
• used to perceive pattern , texture and shape

Question 10

SA II

Answer 10

• big receptive fields
• low temporal
• low spatial
• respond to stretch and hand conformation

Question 11

FA I

Answer 11

• small rf
• dense in the upper dermis
• high spatial resolution
• high temporal resolution
  -respond to motion and low frequency
• used for slip and maintaining grip control

Question 12

FA II

Answer 12

• large rf
• sparse density in the lower dermis
• low spatial
• high temporal
• high frequency vibrations
• used for perceiving fine textures through vibrations

Question 13

C-Tactile mechanoreceptors

Answer 13

receptors that are only present in hairy skin which respond to slow, gently pleasnt touch

Question 14

two point discrimination

Answer 14

psychophysics test to asses the spatial resolution (to point theshold) of the skin
- how far a part do two points have to be for us to feel them as 2

Question 15

temporal resolution of touch

Answer 15

we can discriminate touches that are about 5ms apart

Question 16

Braille

Answer 16

SA I are used for this
FA I are kinda good at it too

Question 17

mechanoreceptors in grip control

Answer 17

FA I is very useful in load phase when it is gripping an object to lift it. FA II detect the additional forces after its lifted.

Question 18

thermoception

Answer 18

sense of temperature

Question 19

themoreceptors

Answer 19

we have separate hot ad cold fibers.
they respond when temperature goes below or above baseline
- within the range of 17-43 c

Question 20

nociception

Answer 20

pain thet arises from potential or actual tissue damage due to physical trauma

Question 21

2 types of nociceptors

Answer 21

1. c-fibers
2. A-delta

• 2 kind of fibers makes pain come in 2 waves

Question 22

C-fibers

Answer 22

unmeylinated pain receptors that cause a slower reaction

Question 23

a-delta fibers

Answer 23

lightly myelinated fibers that have faster responses

Question 24

other types of pain

Answer 24

• hyperaglesia: inflammatory
• neuropathic

Question 25

proprioception

Answer 25

sense of where things are relative to each other in the boy

Question 26

types of proprioceptive organs

Answer 26

1. muscle spindles 2. golgi tendons 3. joint receptors

Question 27

muscle spindles

Answer 27

- they sense lenght and change of lenght of the muscle and isometric force in afferent nerves

Question 28

types of muscle spindles

Answer 28

type 1: for dynamic muscles type 2: for stati lenght

Question 29

golgi tendon organs

Answer 29

proprioceptor receptor that sense muscle tension - so our muscle know what its force output is

Question 30

joint receptors

Answer 30

used for telling joint when they are reaching their maximum limits in range of motion

Question 31

dermatones

Answer 31

areas of skin that are innervated by different levels of the spinal cord

Question 32

spinal cord composition

Answer 32

- grey matter (ell bodies) is on the inside and the whte matter is on the outside. - ventral side has motor neurons - dorsal has sensory

Question 33

path into the spinal cord

Answer 33

sensory afferent neurons enter though the dorsal root, passing through the dorsal root ganglion

Question 34

pathways of senory signal to the brain

Answer 34

1. dorsal column-medial lemniscal pathway 2. spinothalamic pathway

Question 35

DCML pathway

Answer 35

tactile and proprioception signals travel out of the spine and make their first synapse in the medulla where they cross contrallaterally to the VP in the thalamus then to S1

Question 36

spinothalamic pathway

Answer 36

signals from pain and thermal receptors synapse in the spinal cord and cross there to the medulla then the thalamus to the S1

Question 37

Primary somatosensory cortex

Answer 37

Subregion of the somatosensory cortex which is the first to receive somatosensory signals (in the central gyrus of the parietal lobe)

Question 38

somatotopic map

Answer 38

a mapping of the body surface onto the somatosensory cortex, whereby adjacent locations on the cortex receive signals from adjacent locations on the body - not proportional

Question 39

homunculus

Answer 39

a representation of the body if the area of skin was proportional to the size of the cortex that represents that body part

Question 40

Secondary somatosensory cortex

Answer 40

subregion of the somatosensory region which receives signals from area s1

Question 41

areas of the S1

Answer 41

3a 3b 1 2

Question 42

Area 3a

Answer 42

receives proprioceptive signals and discriminative nociceptive signals

Question 43

area 3b

Answer 43

receives tactile signals and discriminative nociceptive signals

Question 44

Area 1

Answer 44

receives tactile information

Question 45

Area 2

Answer 45

recieves proprioceptive signals

Question 46

pathways after S1

Answer 46

after s1 the tactile and proprioceptive information split into dorsal and ventral pathways

Question 47

dorsal pathway of touch

Answer 47

the where pathway that carries tactile information in planing action. goes throuhg posterior parietal cortex to premotor cortex

Question 48

ventral pathway of touch

Answer 48

the what pathway that carries proprioceptive and tactile signals to help indentifiy object shape and qualities. - s1 --> s2 --> hippocampus --> prefrontal cortex

Question 49

haptic perception

Answer 49

actively using touch to perceive and identify object by their 3d structure and other material propertie - uses the other somatosensory sense too