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Flashcards in Somesthesis Lec14 Deck (59):
1

Tactile mechanoreceptors can be slowly adapting which respond to __ stimuli

enduring

2

Tactile mechanoreceptors can be rapidly adapting whuch respond to ___ stimuli

the onset of

3

which receptors have encapsulated endings?

ruffinis and meissners

4

___ rceptors respond really quickly

pacicinian

5

describes merkel receptors signals

have an initially strong signal that partially adapts + a weaker signal of slower adaptation

6

___ and ___ are slow adapting receptors

merkels and ruffinis (sounds like old peoples names.. so slow)

7

___ and ___ are rapdi adapting receptors

pacianian and meissers

8

____ have lamina with gelatinous, rapidly dissipating fluid in between the layers

pacinian

9

Two point discrimination is a good measure of ___-

receptor sensitivity

10

High tactile sensibility = Fine spatial discrimination = ____ receptor density

High

11

High receptor density = ____ receptive fields

Small

12

Areas of greatest sensitivity (highest receptor density) are the (3)

hand, face, and foot

13

receptor with best spatial resolution?

merkels

14

receptor with best temporal resolution?

Meissner (RA) & Pacinian (RA)

15

where do the DML and ALS pathways enter the SC?

via dorsal root ganglion --> lateral margin of the dorsal columns

16

Medial branch = ____ tract to brain

Dorsal Column

17

Lateral branch = ____ tract to brain

Anterolateral

18

Sensory nerves are segregated by ___ and ___ within the dorsal columns of the spinal cord.

receptor type and modality

19

In addition to segregation by receptor type and modality, there is Somatopic organization in dorsal columns of spinal cord. what is most medial? most lateral?

lower limb -- most medial head and neck -- most lateral

20

Dorsal Column Nuclei are the

gracile and cuneate nuclei

21

Spatial Summation: In the Dorsal Column Nuclei

neurons converge onto 2nd order neurons with____ that have both excitatory and inhibitory regions.

 larger receptive fields

22

in the thalamus 

Moving medial-lateral changes ___

place

23

in the thalamus

moving anterior-posterior changes ___

modality

24

S1 has 4 cytoarchitectonic regions: ___

3a, 3b, 1, and 2.

25

Fibers from areas 3a and 3b go to areas ___

1 and 2

26

Each of the 4 areas of S1 has its own independent, complete, ___

parallel sensory map.

27

ptimary submodality of 3a

deep tissue input 

28

primary submodality of 3b

cutaneous receptors, SA or RA

29

primary submodality of 1

cutaneous receptors, ra

30

primary submodality of 2

deep pressure

31

in the cortical columns

moving medial-lateral changes ___

place

32

in the cortical columns

moving anterior-posterior changes ___

modality

33

____ seizure progressions follow the homunculus:

Jacksonian

34

Jacksonian seizure progressions follow the homunculus in what order 

from finger to arm to shoulder to back to leg

35

Higher level S1 cells:

____ detect direction of movement

Posterior vertical columns in areas 2 and 1

36

are Topographic representations are modifiable? 

yes, they change with use

37

___ receptors are located in the deeper layers of the skin, and also in deeper tissues. 

ruffinis

38

 Pacinian corpuscles are located ___ and ___

 both immediately beneath the skin and also deep in the fascial tissues of the body.

39

The Pacinian Corpuscle’s ability to respond is based on its unique ____ structure.

lamellar accessory

40

the Pacinian corpuscle will respond with a single action potential for .

Q image thumb

each phase of the stimulus

41

hair receptors

 Slight movement of any hair on the body stimulates another type of receptor that is made up of a___entwining the base of the hair.

 nerve fiber 

42

The receptive field is that portion of the skin___

 directly innervated by the receptor terminals and the area 

43

limitations fo ALS 

poor localizing ability on the body and little capability for fine intensity discrimination

 

*just crude touch

44

Sacral axons enter the spinal cord and are packed near the ____

midline

45

The axons that are added at higher levels are packed at successively more ____

lateral positions.

46

___ become larger in the dorsal column   because they receive convergent input from many primary neurons

Receptive fields

47

why is the receptive field of second order neurons more complicated?

excitatory and inhbiitory regions

48

A punctate stimulus activates several touch receptors to varying ____

degree

49

Punctate stimulus

Each of the primary units influences (2)

1. its own secondary unit

2. also its nearest neighbors

A image thumb
50

The fibers of the medial lemniscus synapse on the ___ of the thalamus.

VPL

51

Sensory information about a particular modality from one part of the body

is processed by collections of neurons that form ___ in the thalamus.

discrete functional units

52

Axons of the ___that subserve a particular modality from a restricted body part form a bundle as they enter the thalamus

medial lemniscus 

53

The medial division of the VPL projects to the ___ portion of the postcentral gyrus.

lateral

54

The lateral division of the VPL projects to the ___ portions of the postcentral gyrus.

medial and superior

55

Most of the thalamic fibers terminate in areas ____ of S1

3a and 3b.

56

Penfield found that stimulation of the postcentral gyrus produced tactile sensations in particular parts of the ___

opposite side of the body.

57

The sizes of areas in the SI are directly proportional to the ___ in each respective peripheral area of the body.

number of specialized receptors

58

3a, 3b, 1, and 2 are adjoining, parallel and they correspond to each other in their ___representation.

medial-to-lateral 

59