Sensory physiology

Question 1

How are peripheral ns. classified

Answer 1

action potential and fiber properties

Question 2

What is the largest sensory afferent fiber type

Answer 2

Ia

Question 3

What is the fastest sensory afferent fiber type

Answer 3

Ia

Question 4

What is the slowest and smallest afferent fiber type

Answer 4

C

Question 5

What kind of receptors respond to prolonged and constant stimulation

Answer 5

SA Receptors

Question 6

What kind of receptors respond only at the beginning or end of a stimulus

Answer 6

RA receptors

Question 7

What kind of receptor is a Meissner corpuscle

Answer 7

RA

Question 8

What sensation is sensed by a Meissner corpuscle

Answer 8

tap/flutter

Question 9

What type of receptor is a hair follicle

Answer 9

RA/SA

Question 10

What type of sensation is felt by a hair follicel

Answer 10

motion/direction

Question 11

What type of receptor is a pacinian corpuscle

Answer 11

RA

Question 12

What is felt by a pacinian corpuscle

Answer 12

vibration

Question 13

What type of receptor is a merkel disc

Answer 13

SA

Question 14

What is felt by a merkel disc

Answer 14

touch/pressure

Question 15

What type of receptor is a ruffini corpuscle

Answer 15

SA

Question 16

What is felt by a ruffini corpuscle

Answer 16

skin stretch

Question 17

What receptor types have large field sizes

Answer 17

Ruffini corpuscle

Pacini corpuscle

Question 18

What receptor types have small field sizes

Answer 18

Merkel disc

Meissner corpuscle

Question 19

What is presynaptic inhibition

Answer 19

neurotransmission controlled by pre and post synaptic inhibitory mechanisms, most powerful form. GABAergic associated of Cl, results in hyperpolarization and less NT release.

Question 20

What is the function of a presynaptic inhibition

Answer 20

Reduces NT release, improves brains ability to localize signal

Question 21

How many layers are in the cortex

Answer 21

6

Question 22

What layers are enlarged in primary sensory cortex

Answer 22

3 and 4

Question 23

What are the main sites of termination of axons from thalamus in the cortex

Answer 23

III and IV

Question 24

What are the main type of output neurons

Answer 24

pyramidal cells

Question 25

What type of neurons are stacked above and below each other

Answer 25

are fundamentally similar

Question 26

What type of neurosn are stacked side by side

Answer 26

significantly different

Question 27

Where is S1 located

Answer 27

postcentral gyrus

Question 28

What is the function of S2

Answer 28

Cognitive touch, comparisons between objects, different tactile sensations and determining whether something becomes a memory

Question 29

Function of S1

Answer 29

Integration of info for position sense as well as size and shape discrimination

Question 30

Function of parieto-occipital-temporal association cortex

Answer 30

analyzes spatial coordinates of self, so names of objects, etc.

Question 31

Function of corticofugal signals

Answer 31

from cortex to relay stations in thalamus/medulla/SC | Control intensity of sensory sensitivity, and typically inhibit/suppress sensory input.

Question 32

What is the law of projection

Answer 32

no matter where on afferent pathway is stimulated, perceived sensation is from origin of sensation (like thumb or something)

Question 33

What is the law of specific nerve energies

Answer 33

no matter where along afferent pathway is stimulated, sensation that will occur is determined by nature of sensory receptor in periphery connected to it

Question 34

What is pain

Answer 34

unpleasant sensory and emotional experience associated with actual /potential tissue damage

Question 35

What is nociception

Answer 35

neural process of encoding noxious stimuli. May be autonomic/behavioral. Pain not be a factor.

Question 36

Pain fibers tend to have what types of afferent fibers

Answer 36

C and Adelta

Question 37

What neuropeptides are expressed in peptidergic free nerve endings

Answer 37

substance p | CGRP

Question 38

What are peptidergic neurons responsive to

Answer 38

NGF

Question 39

Where are peptidergic free nerve endings typically found

Answer 39

most of visceral | half of cutaneous afferents (chronic infl. and visceral pain)

Question 40

What is non-peptidergic free endings responsive to

Answer 40

GDNF

Question 41

Where are non-peptidergic free endings found

Answer 41

few visceral | half of cutaneous afferents (diabetic neuropathy)

Question 42

What does TRPV1 respond to

Answer 42

capsaicin

Question 43

What does TRPA1 respond to

Answer 43

mustard stuff

Question 44

What does TRPM8 respond ot

Answer 44

menthol

Question 45

What is the purpose of the TRP receptors

Answer 45

ligand-gated nonselective cation channel that is permeable to Ca, Na or K

Question 46

What are some other signaling modalities that sense pain

Answer 46

SP *CGRP Histamine Kinins

Question 47

What do C fibers respond to

Answer 47

EAA and SP/CGRP

Question 48

What do Adelta fibers respond to

Answer 48

EAA

Question 49

What is the gate control theory

Answer 49

absence of input from C fibers, tonically active inhibitory interneuron suppresses pain pathway (turns interneuron on that has inhibitory function) Known as Abeta fibers

Question 50

What is descending inhibition

Answer 50

activated by opoiates/ eaa/cannabinoids Descends to LE or Raphe nucleus serotonin and NE release into dorsal horn and activate inhibitory interneurons release opiates, that activate mu receptors on C fiber, reduces SP from C fiber and reduces nociception

Question 51

What is another chemical that can cause pain because of molecular inflammation

Answer 51

bradykinin, which increases excitability and facilitates activation of dorsal horn neurons

Question 52

What is the function of the insular cortex

Answer 52

interpret nociception, integrates all signals related to pain

Question 53

What is asymbolia

Answer 53

damage to insular cortex that means you can feel pain, but don't care about it

Question 54

What is the function of the amygdala regarding pain

Answer 54

emotions associated with it

Question 55

Where does visceral input go for pain

Answer 55

hypothalamus and medulla, integrates physiological changes

Question 56

What type of pain is cutaneous

Answer 56

fast pain and slow pain

Question 57

What type of pain is deep pain (periosteum, etc.)

Answer 57

usually dull and achy, muscle spasms

Question 58

What type of pain is muscle (injury/ischemia)

Answer 58

fast pain and slow pain

Question 59

What type of pain is visceral

Answer 59

poor localization, sensitive to stretch, referred pain.