EX1; Trigeminal System Flashcards Preview

AU14 Physiology > EX1; Trigeminal System > Flashcards

Flashcards in EX1; Trigeminal System Deck (65):
1

What is the functional significance of the trigeminal system

speech production; positioning tongue for articulation
positioning food for chewing efficacy
salvation

2

What is stereognosis regarding the trigeminal system

3-dimensionality of objects in the mouth
size, texture, hardness

3

what is flavor regarding the trigeminal system

taste and olfaction (special senses)
texture, temperature, chemesthesis

4

What sensations are evoked in the mouth and perioral region regarding trigeminal

touch
temperature
pain
proprioception info regarding the position of the tongue and jaws

5

Trigeminal fibers can be activated by some chemical stimuli including spices, high concentrations of acid/salt, and some compounds common in dentistry; this is termed what

chemesthesis

6

What are the three main branches of trigeminal

opthalmic
maxillary
mandibular

7

Which main branch contains both motor and sensory, as opposed to just sensory

mandibular

8

Where are the cell bodies for the trigeminal nerve located

in the trigeminal (semi-lunar/Gasserian) ganglia in the temporal bone

9

At which level of the brain do fibers (axons) of the trigeminal nerve enter and bifurcate into ascending and descending branches ultimately terminating in different brainstem structures with different functions

pons

10

The ascending branch of trigeminal ends where

in the principal nucleus

11

What is the function of the ascending branch of trigeminal

light touch perception

12

The descending branch of trigeminal ends where

in the spinal trigeminal nucleus

13

What are the three divisions of the spinal trigeminal nucleus

nucleus oralis
nucleus interpolaris
nucleus caudalis

14

What is the function of nucleus oralis

light touch perception

15

What is the function of nucleus interpolaris

temperature perception

16

What is the function of nucleus caudalis

pain perception

17

The representation of the head and neck is somatotopically organized within each sensory nucleus and sub nucleus in the brainstem, what are these

thalamus
ventral posterior medial nucleus
somatosensory cortex in the parietal lobe

18

What five things can peripheral nerve fibers be classified as

fiber size
conduction velocity
threshold
modality (what they respond to)
type of receptors at the end of the sensory axon

19

What are the two types of rapidly adapting mechanoreceptors

small receptive fields
large receptive fields

20

What are the two types of slowly adapting mecahnoreceptors

small receptive fields
large receptive fields

21

This is the deformation or stretch of the axon membrane that opens Na channels, they by polarizing the axon and causing impulses (action potentials)

transduction

22

Recent studies suggest that these sodium channels influencing transduction belong to which super family

epithelial NaCl channels; ENac

23

Mechanical transduction may occur through which specific channels

transient receptor potential channels

24

In the hand, there is a correlation between receptor what

structure and function

25

The Ruffini corpuscle (type II SA) is involved with what sensation

skin stretch

26

The pacinian corpuscle is involved with what sensation

vibration

27

The response properties of mechanoreceptors are influenced by three sources

degree of myelination
location of receptor (superficial/deep)
structure of the ending (meissner, ruffini, etc)

28

The Meissner corpuscle is involved with what sensation

light touch/spatial discrimination

29

The merkel receptor is involved with what sensation

pressure

30

This receptor ending is surrounded by layers of Schwann cells and collagen

pacinian

31

When a stimulus is applied to pacinian corpuscles the lamellae resist the force such that only what occurs

the initial impact of the stimulus makes it to the transduction site

32

When the force is removed from the pacinian corpuscle compressed lamellae imparts what

an off-response to the receptor

33

These are monofilaments calibrated to bend at specific forces, usually measured in grams; used to establish touch tresholds

von frey hairs

34

Which portion of the face has a lower threshold for two-point discrimination

facial midline

35

Oral and facial tissues show specialized patterns of what

innervation and in some instances different anatomical receptor types than are found in the hand

36

This is the recording from human nerves; map of receptive fields; determines neuron properties

microneurography

37

True or False
Females are typically more two point discrimination sensitive than males

True

38

The infraorbital nerve does not contain these fibers, and what does this mean

no RAII or Pacinian corpuscles
we can still feel vibration on our face, the receptor in the hand is thought to mediate this (low vibrotactile sensitivity)

39

The tongue is innervated by this mandibular nerve, although sensitive, there is not a large varies of receptor endings

lingual nerve

40

What is the most common type of receptor endings in the lingual nerve

non-encapsulated "coiled nerve endings" referred to as Krause end bulbs

41

What type of responses are recorded in the tongue

rapidly adapting (RA)
slowly adapting (SA)
which is one of a kind, especially regarding to its ending
*high degree of sensitivity

42

What two things do Krause end bulbs and Meissner corpuscles have in common

high density and small receipting field at tip
both have rapidly and slowly adapting responses

43

What are four things affecting the origin of trigeminal dysfunction

oral and facial trauma
complete dentures with loss of underlying tissue
infectious disease (periodontitis)
dental and surgical procedures

44

True or False
There is much documentation about the mechanoreceptors in the TMJ and evidence indicated these receptors help mediate interdental sensation

False; there is little evidence, but they do mediate interdental sensation

45

What branches of mandibualr; trigeminal innervate TMJ

auriculotemporal
masseter
posterior deep temporal

46

Where is the most dense innervation of TMJ

posterior and lateral portion of capsule

47

What types of nerve endings are found in TMJ

free nerve endings (C-fibers) predominate with only a few specialized endings such as refine endings or golgi tendon organs

48

Which teeth are more sensitive based upon pressure applied using von frey hairs

midline teeth

49

What is impacted most with trigeminal disfunction following third molar extraction

the lip is impacted the most; can lead to tongue biting and hot burns

50

What nerve innervate the PDL

branches of superior and inferior alveolar nerves

51

What type of nerve ending is found in the PDL

unencapsulated Ruffini type endings

52

What nuclei and ganglia send fibers to innervate the PDL; they may play a role in different functions

trigeminal ganglion
mesencephalic nucleus

53

Directional sensitivity of the PDL shows that when forces are directed to the tooth from this direction, the response is the largest

distal direction

54

These specific fibers also show directional sensitivity

rapidly adapting

55

These connections are part of the ascending sensory pathway that leads to conscious perception via the principal trigeminal nucleus that projects to the VPM in the thalamus and then o the somatosensory cortex

trigeminal ganglion

56

Trigeminal ganglion fibers also project to sub nucleus orals, which then projects to motor trigeminal nucleus to produce what

jaw opening reflex via the anterior digastric muscle

57

These projections can cause salivary secretion via connections to the brainstem salivary nuclei

mesencephalic trigeminal nucleus

58

An example of rapidly adapting response is as the stimulus is applied more rapidly, what happens to the response latency

it becomes shorter

59

clincial conditions such as periodontitis can increase what of PDL

increase thresholds (lower sensitivity)

60

The location of what in the PDL determines sensitivity

Ruffini endings

61

Denture and implant patients have trouble with force regarding what

they have trouble controlling force but do not have trouble generating force

62

There is a wide/narrow variation in the perception of warmth in and around the oral and facial regions

wide

63

There is more/less variation for cold sensation of which is generally perceived more intensely than warmth

less

64

Temperature sensitive fibers typical respond to a range of stimuli classified as what depending on the peak response

cold or warm

65

Many of the different these receptors respond to temperature and some receptors also respond to specific chemical stimuli

TRP (transient receptor potential)