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Flashcards in 3,4,5 Deck (50):
1

4 main stimulus attributes

Modality/quality
Intensity
Location
Duration

2

Transduction definition

Transformation of physical energy into neural signal

3

Adequate stimulus

Type of energy that a given receptor type is most sensitive to

4

Somatosensory and olfaction have stimulus contact _

Vision, audition, vestibular and taste have stimulus contact _ which then goes to _

Primary afferent neuron

Receptor cell
Afferent neuron

5

TRP:

Transient receptor potential

6

3 indirect g-protein coupled receptor systems

Olfaction
Vision
Taste

7

3 ways to increase intensity

Increase stimulus intensity
Increase receptor potential
Increase # of action potentials

8

Lateral inhibition improves _ _

Spatial localization

9

Sensory maps are _
_ and _ affect them

Dynamic
Experience and neurological injury

10

5 areas of trigeminal perception

Touch
Proprioception
Temperature
Pain
Chemesthesis

11

How does the trigeminal influence flavor

Texture, temperature, chemesthesis

12

Ophthalmic and maxillary branches are _ only but the mandibular is _ and _

Sensory only
Sensory and motor

13

A-beta fibers detect:
A-delta fibers detect:
C fibers detect:

Touch, proprioceptive
Touch, temperature
Temperature

14

SA I vs SA II receptors

RA I vs RA II receptors

SA I - merkel disc, pressure
SA II - ruffini ending, skin stretch

RA I - meissner corpuscle, spatial disc.
RA II - pacinian corpuscle, vibration

15

3 mechanisms of mechanotransduction

1. ENaC
2. TRP
3. Piezo1 and Piezo2

16

Cell bodies for trigem nerve are found where

Trigeminal/gasserian/semilunar ganglia

17

Trigeminal nerve fibers enter the brain at what level

Pons

18

Ascending trigeminal fibers end where? Descending?

Asc. - principal/main/chief/pontine nucleus

Desc. - spinal trigeminal nucleus

19

3 subdivisions of spinal trigeminal nucleus, and functions of each

1. Nucleus oralis - light touch
2. Nucleus interpolaris - temp.
3. Nucleus caudalis - pain

20

Chemesthesis:

Trigeminal fibers can be activated by chemical stimuli

21

Transduction:

Deformation or stretch of the axon membrane that opens sodium channels

22

Response of mechanoreceptors is influenced by what 3 things

Degree of myelination
Location of receptor
Structure of the ending

23

Most common receptor ending in tongue

Coiled nerve endings

24

What unique nerve ending is found in the PDL

Ruffini type (unencapsulated)

25

The PDL is innervated by what two things

Trigeminal ganglion (superficial in ligament)
Mesenchephalic nucleus (near apex)

26

How many families of TRP's

8

27

TRPs are made of how many transmembrane domains?

Cation channel is between which domains

6

5/6

28

Which receptors primarily transduct pain

TRP

29

TRPV1 responds to what 3 things

Capsaicin
Heat
Protons

30

Chemesthesis can produce what sensations

Painful/nonpainful
Burning
Tingling
Astringency
Pungency

31

Which 4 branches of trigeminal nerve have prominent chemesthesis

Ethmoidal
Posterior palatine
Nasopalatine
Lingual

32

Both olfaction and chemesthesia can be activated in what two ways

Orthonasally
Retronasally

33

Nasal chemesthesis is produced by what two receptors

TRP receptors
Taste receptors on specialized olfactory epithelium cells

34

Single chemosensory cells are what

Cells that are activated by nasal irritants to initiate respiratory reflexes

35

Chemesthesis is a _ threshold chemosensitivity

High

36

Pulpal C fibers have a _ latency

Long

37

Hyperalgesia:

Greater responsiveness to stimuli

38

Prostaglandins do what do sensitivity

Change threshold of sensitivity, make more sensitive

39

T/F prostaglandins directly depolarize neurons

FALSE, they change sensitivity

40

Inflammation does what to threshold, and how

Lowers it

Ca++ activated phosphorylation of VR1, increase in receptor number

41

Substance P and CGRP sensitize how

Neurogenic inflammation

42

Which 3 cells directly stimulate nociceptors

Histamine
Bradykinin
5-HT

43

What two things sensitize nociceptors

Protaglandins
Proton release

44

What two main things happen when hyperalgesia occurs

Greater responsiveness to stimuli

Pain is spontaneous and prolonged

45

Causalgia:

Allodynia:

Sympathetic nerve dystrophy:

C: burning pain
A: light touch leads to pain
SND: temp induced pain

46

Neuroma:

Unorganized mass of nerve tissue from regenerative capacity of nerves

47

Schwann cells make what for regen. Axons, and secrete what that regulates gene expression and promotes sprouting

Laminin

NGF

48

Inflammatory cells release factors that do what 3 things

1. Algesics - stimulate nociceptor cells directly

2. Stimulate other cells to release algesics

3. Involved in process of sensitization

49

What is ectopic discharge, and when does it occur?

When a neuron responds from stimulation of cell body (not receptor end)

Happens after nerve damage

50

Why is a neuroma painful? 2 reasons

Sprouting makes a nociceptor be stimulated from erroneous location

Ephaptic connections b/t neurons in neuroma lower threshold