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Flashcards in trigeminal Deck (46):
1

the ascending branch of the trigeminal n. ends in _____, which functions primarily for _____

primary sensory nucleus (main/chief/pontine); light touch perception

2

the descending branch of the trigeminal n. ends in the ____ which has 3 subdivisions:

ends in spinal trigeminal nucleus
3 divisions: nucleus oralis (light touch perception)
nucleus interpolaris (temperature)
nucleus caudalis (pain)

3

there are two types of ____ mechanoreceptors and two types of ____ mechanoreceptors

rapidly adapting; slowly adapting

4

____ for mechanoreception is the deformation or stretch of the axon membrane that opens ____ channels, thereby depolarizing the axon and causing impulses

transduction; sodium

5

type of sodium channel involved in mechanoreception

epithelial NaCl channels

6

mechanoreception may also occur thru specific ______ channels, an example of which are piezo 1 and piezo 2

transient receptor potential (TRP)

7

in the ____, there is a correlation between receptor structure and function

hand

8

response properties of mechanoreceptors are influenced by:

1. degree of myelination
2. location of the receptor (superficial/deep)
3. structure of the ending (degree of encapsulation)(Meissner/Ruffini)
4. transduction

9

pacinian corpuscles are designed to detect ____ stimuli

vibratory

10

2 types of superficial endings

meissner's corpuscles and merkel disc

11

2 types of deep endings

pacinian corpuscle and ruffini ending

12

4 types of endings and their types

meissner corpuscle (RAI)
pacinian corpuscle (RAII)
merkel disc (SAI)
ruffini ending (SAII)

13

4 types of endings and what they detect

meissner corpuscle- light touch/spatial discrimination
pacinian corpuscle- vibration
merkel disc- pressure
ruffini ending- skin stretch

14

lamellae of pacinian corpuscles are composed of ____ and ____ separated by ___ to provide a cushion to applied stimulus

cells; collagen fibers; fluid

15

upon release of stimulus, ____ of pacinian corpuscle imparts a ____ response to nerve ending

decompression; 2nd (off)

16

mechanisms of mechanotransduction

1. ENaC (epithelial Na channels)
2. TRP channels
3. Piezo1 and Piezo2

17

____ are used to measure two-point discrimination (tactile sensitivity)

disks

18

____ are monofilaments calibrated to bend at specific forces, usually measured in grams

von frey hairs (semmes-weinstein monofilaments)

19

von frey hairs are used to establish ____

touch thresholds

20

facial ____ structures have a lower threshold for two-point discrimination

midline

21

the technique of _____ can be used to record nerve impulses from the infraorbital nerve innervating the facial region in human subjects

microneurography

22

there are no ____ type responses or ____ in the face (but this receptor type is present in the hand)

RA II; Pacian corpuscle

23

lack of pacinian corpuscles leads to low ____ sensitivity of the face

vibrotactile

24

____ endings predominate in the tongue

unencapsulated

25

the most common type of receptor ending in the tongue is the ____ which looks very similar to _____ in the hand

Krause end bulbs (non-encapsulated "coiled nerve endings"); meissner corpuscle

26

the tongue has both rapidly and slowly adapting mechanoreceptors despite:

having only one kind of ending (compared to the hand)

27

there is ____ of ____receptive fields at the tip of the tongue

high density; small

28

on the face, the ____ have the lowest two point thresholds

lips

29

the ____ and ____ nerves can sometimes be damaged during 3rd molar extraction

lingual; mental

30

origins of trigeminal dysfunction

oral and facial trauma
complete dentures with loss of underlying tissues
infectious diseases (periodontitis)
dental and surgical procedures (tooth extraction and osteotomy)

31

merkel cells are found in ____, ____ and _____

buccal mucosa; gingiva; palate

32

merkel cells contain ____ and ____ that can promote cell division

peptides; growth factors

33

merkel cells are found in areas with ______; there are more MCs in ____ patients that use soft tissues for chewing

high masticatory load (i.e. tissues subject to mechanical stress); edentulous

34

studies indicate that receptors found in the TMJ help mediate _____

interdental sensation

35

innervation of TMJ

auriculotemporal, masseteric, and posterior deep temporal branch of the trigeminal n.

36

there is dense innervation of ____ and ____ portions of TMJ capsule

posterior; lateral

37

_____ predominate in the TMJ with only a few specialized endings such as ____ or ____

free nerve endings; Ruffini endings; golgi tendon organs

38

innervation of the PDL

branches of superior and inferior alveolar nerves

39

most abundant type of ending found in the PDL

unencapsulated ruffini type endings

40

TMJ mechanoreceptors are innervated by ____, mostly ____

mandibular branch; auriculotemporal

41

location of ____ in PDL determines sensitivity

Ruffini ending

42

PDL receptor function

-detect force to teeth
-interdental discrimination
-stereognosis
-jaw reflexes
-salivation

43

trigeminal ganglion connections are part of the ascending sensory pathway that leads to _____ via the principal trigeminal nucleus that projects to ____ and then to _____

conscious perception; VPM in the thalamus; somatosensory cortex

44

some TG fibers project to subnucleus oralis which then projects to the ____ to produce a _____ reflex via the anterior digastric muscle

motor trigeminal nucleus; jaw-opening

45

mesencephalic trigeminal nucleus projections can cause ____ via connections to the _____

salivation; brainstem salivary nuclei

46

for warm sensitivity- ____ is least sensitive of intra-oral tissues

buccal mucosa