Somesthesis Lec14

Question 1

Tactile mechanoreceptors can be slowly adapting which respond to __ stimuli

Answer 1

enduring

Question 2

Tactile mechanoreceptors can be rapidly adapting whuch respond to ___ stimuli

Answer 2

the onset of

Question 3

which receptors have encapsulated endings?

Answer 3

ruffinis and meissners

Question 4

___ rceptors respond really quickly

Answer 4

pacicinian

Question 5

describes merkel receptors signals

Answer 5

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

Question 6

___ and ___ are slow adapting receptors

Answer 6

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

Question 7

___ and ___ are rapdi adapting receptors

Answer 7

pacianian and meissers

Question 8

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

Answer 8

pacinian

Question 9

Two point discrimination is a good measure of ___-

Answer 9

receptor sensitivity

Question 10

High tactile sensibility = Fine spatial discrimination = ____ receptor density

Answer 10

High

Question 11

High receptor density = ____ receptive fields

Answer 11

Small

Question 12

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

Answer 12

hand, face, and foot

Question 13

receptor with best spatial resolution?

Answer 13

merkels

Question 14

receptor with best temporal resolution?

Answer 14

Meissner (RA) & Pacinian (RA)

Question 15

where do the DML and ALS pathways enter the SC?

Answer 15

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

Question 16

Medial branch = ____ tract to brain

Answer 16

Dorsal Column

Question 17

Lateral branch = ____ tract to brain

Answer 17

Anterolateral

Question 18

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

Answer 18

receptor type and modality

Question 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?

Answer 19

lower limb – most medial head and neck – most lateral

Question 20

Dorsal Column Nuclei are the

Answer 20

gracile and cuneate nuclei

Question 21

Spatial Summation: In the Dorsal Column Nuclei

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

Answer 21

larger receptive fields

Question 22

in the thalamus

Moving medial-lateral changes ___

Answer 22

place

Question 23

in the thalamus

moving anterior-posterior changes ___

Answer 23

modality

Question 24

S1 has 4 cytoarchitectonic regions: ___

Answer 24

3a, 3b, 1, and 2.

Question 25

Fibers from areas 3a and 3b go to areas \_\_\_

Answer 25

1 and 2

Question 26

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

Answer 26

parallel sensory map.

Question 27

ptimary submodality of 3a

Answer 27

deep tissue input

Question 28

primary submodality of 3b

Answer 28

cutaneous receptors, SA or RA

Question 29

primary submodality of 1

Answer 29

cutaneous receptors, ra

Question 30

primary submodality of 2

Answer 30

deep pressure

Question 31

in the cortical columns moving medial-lateral changes \_\_\_

Answer 31

place

Question 32

in the cortical columns moving anterior-posterior changes \_\_\_

Answer 32

modality

Question 33

\_\_\_\_ seizure progressions follow the homunculus:

Answer 33

Jacksonian

Question 34

Jacksonian seizure progressions follow the homunculus in what order

Answer 34

from finger to arm to shoulder to back to leg

Question 35

Higher level S1 cells: \_\_\_\_ detect direction of movement

Answer 35

Posterior vertical columns in areas 2 and 1

Question 36

are Topographic representations are modifiable?

Answer 36

yes, they change with use

Question 37

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

Answer 37

ruffinis

Question 38

Pacinian corpuscles are located ___ and \_\_\_

Answer 38

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

Question 39

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

Answer 39

lamellar accessory

Question 40

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

Answer 40

each phase of the stimulus

Question 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.

Answer 41

nerve fiber

Question 42

The receptive field is that portion of the skin\_\_\_

Answer 42

directly innervated by the receptor terminals and the area

Question 43

limitations fo ALS

Answer 43

poor localizing ability on the body and little capability for fine intensity discrimination \*just crude touch

Question 44

Sacral axons enter the spinal cord and are packed near the \_\_\_\_

Answer 44

midline

Question 45

The axons that are added at higher levels are packed at successively more \_\_\_\_

Answer 45

lateral positions.

Question 46

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

Answer 46

Receptive fields

Question 47

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

Answer 47

excitatory and inhbiitory regions

Question 48

A punctate stimulus activates several touch receptors to varying \_\_\_\_

Answer 48

degree

Question 49

Punctate stimulus Each of the primary units influences (2)

Answer 49

1. its own secondary unit 2. also its nearest neighbors

Question 50

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

Answer 50

VPL

Question 51

Sensory information about a particular modality from one part of the body is processed by collections of neurons that form ___ in the thalamus.

Answer 51

discrete functional units

Question 52

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

Answer 52

medial lemniscus

Question 53

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

Answer 53

lateral

Question 54

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

Answer 54

medial and superior

Question 55

Most of the thalamic fibers terminate in areas ____ of S1

Answer 55

3a and 3b.

Question 56

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

Answer 56

opposite side of the body.

Question 57

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

Answer 57

number of specialized receptors

Question 58

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

Answer 58

medial-to-lateral