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Flashcards in trigeminal nerve lecture Deck (45):
1

what stimuli can the trigeminal nerve detect?

pain
touch
temperature
proprioception
chemesthesis (common chemical sense)
Stereognosis
Flavour

2

___________ is the ability to sense 3-dimensionality, such as size, texture and hardness

Stereognosis

3

The trigeminal nerve has ___ main branches. name them:

3 branches:

1) Opthalmic (sensory only)
2) Maxillary (sensory only)
3) mandibular (Sensory & Motor)

4

what are the 3 names for the trigeminal ganglion?

Trigeminal ganglion
Gasserian ganglion
Semilunar ganglion

5

name the segments of the spinal trigeminal nucleus

1) oralis
2) interpolaris
3) caudalis (medullary dorsal horn)

6

before signals from the principal sensory nucleus reach the primary somatic sensory cortex (in the parietal cortex), where do the nerve fibers synapse?

Ventral Posterior Medial Nucleus of the Thalamus

7

which types of sensory neurons are found in the Trigeminal nerve?

A-beta

A-delta

C fibers

8

what are the 4 types of mechanoreceptors?

1) meissners corpuscle (RA1)
2) Merkel disks (SA1)
3) pacinian corpuscle (RA2)
4) Ruffini endings (SA2)

9

which type of mechanoreceptor senses vibration? Pressure? discriminative touch? Skin stretch?

Vibration- Pacinian corpuscle

Pressure- Merkel disk

Discriminative touch- Meissners corpuscle

Skin stretch- Ruffini endings

10

how do ENaC channels transmit signals concerning the "stretch" of skin?

Stretch causes membrane channels to open leading to depolarization

11

Factors Influencing Mechanoreceptor function:

1. Size of fiber and degree of myelination

2. Location or receptor (superficial vs deep)

3. Structure of ending, e.g. degree of encapsulation

4. Transduction
- ENacS & TRP channels

12

what do Von Frey Hairs measure?

Touch discrimination

13

T/F: males typically have a higher sensitivity to 2-point discrimination

False

females are more sensitive

14

what mechanoreceptors does the infraorbital nerve contain? which is it missing?

1. Both SAI and SAII

2. RAI

3. No RAII ****no pacinian corpuscles

15

due to its lack of RA2, what sensation can the infraorbital nerve not detect?

vibration

16

the Perioral and Facial area has low __________ sensitivity

vibrotactile

17

Lack of _________ leads to low vibrotactile sensitivity of face

Lack of pacinian corpuscles

18

___________ mechanoreceptor Endings Predominate in Tongue (and palate)

Unencapsulated

19

the coiled endings (Krause end bulbs) in the mouth are similar to what structure

Meissner corpuscles

20

Tongue has both rapidly and slowly adapting mechanoreceptors despite what?

only having one kind of ending! (compare to hand)

21

the tongue has High density and small receptive fields in what area?

at the tip

22

the face has a lack of what receptor? what does it have a low sensitivity to?

Lack of pacinian corpuscles (RAII)

Low vibration sensitivity

23

Unlike the face, the tongue uses _________ receptors, giving it a high degree of _______ sensitivity

Krause end bulbs
High degree of tactile sensitivity

24

Trigeminal Dysfunction Following Third Molar Extraction:

Lip impacted more often than tongue

Can lead to tongue biting And hot fluid burns & tics:
e.g. fingers to chin

Taste problems not commonly reported

25

what is the rate of nerve dysfunction following third molar extraction?

1.2%

(only 0.2% of patients had permanent damage)

26

what nerves innervate the TMJ?

1) Masseter nerve (anterior)
2) posterior deep temporal nerve (medial)
3) Auriculotemporal nerve (posterior)

27

TMJ Mechanoreceptors are mostly what type?

mostly free nerve endings (c-fibers)

Ruffini > Golgi tendon organs > Pacinian

28

T/F: posterior teeth (molars) are more sensitive than anterior teeth (incisors)

False: anterior teeth more sensitive than posterior

29

which type of nerve endings are responsible for the innervation of the PDL?

1) Complex Ruffini

2) Simple Ruffini

3) Unmyelinated Free nerve endings

30

Nerves from the Trigeminal ganglia are more abundant at what part of the PDL? what about nerves from the mesencephalic nucleus?

Trigeminal ganglia- gingival to middle portion of PDL

Mesencephalic nucleus- Apex of tooth

31

the mechanoreceptors of the PDL are ________ sensitive

rate

(faster the force is applied- higher firing rate)

32

T/F: the mechanoreceptors of the PDL have directional sensitivity

true

33

PDL nerve fibers are generally more sensitive to forces in what directions?

labial and distal forces

34

Denture & Implant Patient have Trouble __________ Force but do not have Trouble _________ Force

Denture & Implant Patient have Trouble Controlling Force but do not have Trouble Generating Force

35

Denture Patients Show Less _________ Sensitivity

Stereognosis Sensitivity

36

PDL Receptor Function:

detect force to teeth
interdental discrimination
stereognosis
jaw reflexes
salivation

37

which type of nerve fibers in the mouth are temperature sensitive?

A-delta and C-fiber


(A-beta fibers are only proprioceptive and touch)

38

for sensitivity to heat, the ________ is most sensitive of intra-oral tissues

tongue tip

39

Temperature Transduction is Mediated by ___________________

Transient Receptor Potentials
TRP channels

40

the trigeminal motor nucleus, and the trigeminal principal sensory nucleus, are both found in which CNS structure?

the pons

41

what are the 2 types of "RA" (rapid adaptation) mechanoreceptors?

which has a small, sharp receptive field?

Meissners and Pacinian corpuscles

Meissners have a small, sharp receptive field

42

which mechanoreceptors are "SA" (slow adaptation)?

which of these 2 has a small, sharp receptive field?

Merkel disks and Ruffini endings

merkels disks have a smaller, sharper receptive field

43

where do the "reflex" pathway fibers of the PDL travel to?

-trigeminal mesencephalic nucleus

then to the:
-salivary nucleus
-motor nucleus

44

where do the "sensory" pathway fibers of the PDL travel to?

A) trigeminal principal sensory nucleus
B) Spinal trigeminal nucleus (oralis)

45

which section of the Spinal trigeminal nucleus receives temperature stimuli?

interpolaris