Trigeminal System Flashcards Preview

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Flashcards in Trigeminal System Deck (33)
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1
Q

3 nucleus’s the the trigeminal system?

A
  1. chief sensory nucleus
  2. trigeminal spinal nucleus
  3. mesencephalic nucleus
2
Q

where is the chief sensory nucleus located?

A

pons

3
Q

where is the trigeminal spinal nucleus located?

A

medulla and spinal cord

4
Q

How does the chief sensory nucleus send off its branches?

A

from each nucleus it sends off an ipsilateral and contralateral branch to the VPM nucleus of the thalamus.

5
Q

how does the chief nucleus nucleus ascend and where does it do to?

A

ascends via the trigeminothalamic tract to the VPM of thalamus

6
Q

does the trigeminal spinal nucleus decussate?

A

yes it does completely

7
Q

the spinal trigeminal nucleus ascends via the ____ to the ____

A

ascends via the trigeminothalamic tract to the VPM of thalamus

8
Q

the principal/ chief nucleus is similar to the _____ pathway?

A

DCML (ascends close to medial lemniscus)

9
Q

the spinal trigeminal nucleus is similar to the _____ pathway?

A

ALS

10
Q

describe the reflex arc of the trigeminal system?

A

sensory info comes from V3 and goes to the mesencephaic nucleus (located in the upper trigeminal spinal nucleus) it the synapses outside the nucleus on a motor branch of V3.

11
Q

how does sensory info make it from the trigeminal ganglion to the spinal trigeminal nucleus?

A

it descends via the spinal trigeminal tract.

12
Q

what does the chief/ principal nucleus mediate?

A

fine touch, joint position and vibration

13
Q

what does the spinal trigeminal nucleus mediate?

A

pain and temperature - associated with ALS

14
Q

where is the spinal trigeminal nucleus located?

A

medulla to c2-c3 - continuous with the dorsal horn

15
Q

what is the trigeminal motor nucleus similar to?

A

homologous to the ventral horn in the spinal cord

16
Q

where is the trigeminal motor nucleus located?

A

medial to the prinicpal/ chief nucleus

17
Q

what is a consensual reflex?

A

it occurs in both sides. the ipsilateral reflex occurs faster than contralateral

18
Q

eye blink response ( touch cornea)
input
output

A

input - trigeminal nerve to chief nucleus (touch cornea)

output - facial nucleus to facial nerve - contract orbicularis oris of both eyes = consensual

19
Q

why is the eyeblink response consensual?

A

b/c the facial nerve splits bilaterally to innervate both sides

20
Q

what is the most common error in dentistry in regards to the inferior alveolar nerve?

A

neglegent implant placement

21
Q

what are you more likely to have complication in extracting, a maxillary 3rd molar or a mandibular 3rd molar?

A
  • mandibular teeth are harder and more dangerous b/c only one nerve (inferior alveolar nerve)
22
Q

what are the 3 types of nerves in the pulp?

A

proprioceptive
nociceptive
sympathetic

23
Q

What type of nerve develops 1st in the pulp?

A

nociceptive nerves for 1st in development- this is why in dentinal tubules

24
Q

what is the second nerve to develop in the pulp?

A

proprioceptive nerves

25
Q

what is the last nerve to develop in the pulp and why?

A

sympathetic nerves are the last to develop. The tooth errups as soo as sympathetics enter. If distorted you will loose the tooth b/c it suppresses inflammation

26
Q

are there parasympathetics in the tooth?

A

no just like skin

27
Q

what does an inferior alveolar nerve block do?

A

anesthetizes the mental , incisive, lingual and long buccal nerve.

28
Q

what happens if a needle enters the inferior alveolar nerve?

A

partial injury with paresthesia - resolves

29
Q

why do you shake someones cheek when giving an injection?

A

b/c tactile sensation is fast and it will block/ overwhelm the nociceptive signaling pathway.

30
Q

the ipsilateral fibers of the chief nucleus travel in the

A

dorsal trigeminothalamic tract

31
Q

the contralateral fivers of the chief nucleus travel in the

A

ventral trigeminothalamic tract

32
Q

what is continuous with the dorsal horn?

A

the spinal trigeminal nucleus

33
Q

what is continuous with the ventral horn?

A

the trigeminal motor nucleus