Exam 2 week 6 ppt 3 CN 5 Trigeminal Nerve

Question 1

what is the number for the Trigeminal nerve?

Answer 1

V

Question 2

name the functional categories of the trigeminal nerve

Answer 2

General sensory (head and face)

• –Opthalmic (V1)
• –Maxillary (V2)
• –Mandibular (V3)

Motor (muscles of mastication)

• Mandibular (V3) division

Question 3

Another name for the Spinal trigeminal nucleus

Answer 3

nucleus of the spinal tract of V

Question 4

what are the three division of the trigeminal nerve?

Answer 4

1. –Opthalmic (V1)
   
   • sensory
2. –Maxillary (V2)
   
   • sensory
3. –Mandibular (V3)
   
   • sensory
   • motor

Question 5

what is the only division of the trigeminal nerve that contains motor function?

Answer 5

Mandibular (V3)

Question 6

What does the Ophthalmic nerve pass through when entering the scull?

Answer 6

Superior Orbital fissure

Question 7

What does the maxillary nerve pass through when entering the scull?

Answer 7

foramen rotundum

Question 8

What does the Mandibular nerve pass through when entering the scull?

Answer 8

foramen ovale

Question 9

Does the trigeminal nerve have high or low innervation density?

Answer 9

What does the Ophthalmic nerve pass through when entering the scull?

Question 10

another name for the spinal tract of V

Answer 10

spinal trigeminal nucleus

Question 11

For the three sensory divisions of the trigeminal nerve, where are the primary afferent cell bodies found?

and what is it equivilant to?

Answer 11

–Primary afferent cell bodies in in the trigeminal ganglion

(equivalent to DRG)

Question 12

where are the 2nd degree neurons for the sensory divisions of the trigeminal nerve? (3)

Answer 12

1. Spinal trigeminal nucleus – (nucleus of the spinal tract of V)
2. Chief (main) sensory nucleus
3. Mesencephalic trigeminal nucleus

Question 13

what is the difference between nociception and pain?

Answer 13

Physiologists distinguish between pain and nociception; where

• nociception refers to signals arriving in the central nervous system resulting from activation of specialized sensory receptors called nociceptors that provide information about tissue damage.
• Pain then is the unpleasant emotional experience that usually accompanies nociception.

http://cell.uchc.edu/pdf/fein/nociceptors_fein_2012.pdf

Question 14

how many regions does the spinal trigeminal nucleus have?

Answer 14

three

§Oralis
§Interpolaris
§Caudalis

Question 15

what are the three regions of the nucleus of the spinal tract of V?

Answer 15

(the nucleus of the spinal tract of V = spinal trigeminal nucleus)

1. Oralis
2. Interpolaris
3. Caudalis

Question 16

Nucleus oralis:

location

transmits

Answer 16

one of three regions of spinal trigeminal nucleus

• Most rostral
• Transmits
  
  • fine (discriminative) orofacial touch

Question 17

Nucleus interpolaris:

location

transmits

Answer 17

one of three regions of spinal trigeminal nucleus

• Mddle position
• Transmits
  
  • Non-discriminative (crude) touch
  • dental pain

Question 18

nucleus caudalis:

location

Transmits

Answer 18

one of three regions of spinal trigeminal nucleus

• Most caudal
• transmits:
  
  • orofacial nociception
  • thermal sensations

Question 19

what is the spinal trigeminal tract?

Answer 19

first degree afferent axons from CN V that go either ascending or descending to 2nd degree neurons in the: nucleus of the spinal tract of V (spinal trigeminal nucleus)

(the words under Dr. Lake’s powerpoint says it could be to the mesencephalic trigeminal nucleus, or the cheif trigeminal nucleus too, but that is not what other sources say. I also emailed Dr. Lake and he replied that it is just the spinal trigeminal nucleus!)

Question 20

bunnies and kitty!

Answer 20

Question 21

cheif sensory nucleus

what does it do?

Answer 21

Chief Sensory Nucleus receives and relays Fine (discriminative) orofacial touch sensations

Question 22

Mesencephalic nucleus

location

what cell bodies are in it & purpose of those neurons?

Answer 22

in the midbrain and rostral pons

contains first degree afferent cell bodies for proprioceptive informatinon from the muscles of mastication - jaw position

(these primary afferents are the only CN V afferents that do not have their cell bodies in the trigeminal ganglion. This nucleus gives rise to our sensation of jaw position and is the afferent limb in reflexes like the jaw jerk reflex.)

Question 23

what primary afferents ore the only CN V afferents that do not have their cell bodies in the trigeminal ganglion?

Answer 23

the 1° afferent cell bodies for proprioceptive information from muscles of mastication.

they synapse in the Mesencephalic Nucleus of the midbrain and rostral pons

Question 24

what nucleus gives rise to our sensation of jaw poistion and is the afferent limb in reflexes like the jaw jerk reflex?

Answer 24

Mesencephalic Nucleus of the midbain and rostral pons

Question 25

The Motor nucleus of V location contains

Answer 25

The Motor nucleus of V is * Located in mid-pons just medial to the primary sensory nucleus of V and * contains LMN to muscles of mastication & tensor tympani

Question 26

what is true about the three ascending tracts of the Trigeminal nerve?

Answer 26

All are decussated secondary axons from trigeminal relay nuclei

Question 27

name the three ascending tracts of teh trigeminal nerve

Answer 27

1. –Lemniscal tract 2. –Thalamic tract 3. –Paramedial tract

Question 28

Ascending V lemniscal pathway (tract): origin becomes

Answer 28

From the Chief sensory & nucleus oralis Becomes the head region of the medial lemniscal tract

Question 29

Ascending V thalamic pathway Origin becomes

Answer 29

–From nucleus interpolaris & nucleus caudalis –Becomes the head region of the antero-lateral tracts

Question 30

Which systems (I think this means pathways) project to the Ventral Posteromedial nucleus of the thalamus (VPM)

Answer 30

Powerpoint said "both systems" after describing the medial lemniscal tract and the anterolateral tracts, so I think it is the following 1. Medial lemniscus system 2. Anterolateral System

Question 31

What are in the Ventral Posteromedial nucleus of the thalamus?

Answer 31

3rd degree neurons of pathway that include the * ascending V thalamic pahtway and * ascending V lemniscal pathway

Question 32

Where does the asending V thalamic pathway synapse with 3rd degree neurons? (after becoming the head region of the anterolateral tracts) Where do the 3rd degree neurons project?

Answer 32

synapse in Ventral Posteromedial thalamus (VPM) projets onto face region along lateral somatosensory cortex

Question 33

Where does the asending V lemniscal pathway synapse with 3rd degree neurons? (after becoming the head region of the medial lemniscal tract) Where do the 3rd degree neurons project?

Answer 33

synapse in Ventral Posteromedial thalamus (VPM) projets onto face region along lateral somatosensory cortex

Question 34

Trigeminal nerve V: ascending tracts: The paramedial ascending system involves projcetctions from where? to where? function

Answer 34

Projections from: * chief sensory and * spinal trigeminal nuclei projcetions to: * midline thalamus & * into limbic system. projections represent the Emotional response to facial touch or pain

Question 35

Four ways to clinically evaluate the Trigeminal Nerve:

Answer 35

1. Corneal reflex 2. Jaw Jerk reflex 3. Sensory tests for fine touch and pin prick to the face 4. Palpate usles of mastication, (have pt resist jaw opening during palpation)

Question 36

How do you test corneal reflex? what is the afferent and efferent limbs?

Answer 36

* Touch cornea with wisp of cotton * normal: produces blinking of the eye with V * V is afferent limb & VII is the efferent limb

Question 37

how does a jaw jerk reflex test work? what are the afferent & efferent limbs? what nuclei are invovled in the reflex?

Answer 37

* tapping of the jaw produces reflex contraction of the muscles of mastication * –Afferent & efferent limb mandibular V3 * –Both thru mesencephalic & motor nucleus of V

Question 38

sensory test for fine touch and pin prick to face

Answer 38

will be discussed later with somatosensory systems

Question 39

what muscles should we palpate in clinical evaluation of the trigeminal nerve & locations? what should we do while palpating?

Answer 39

–Masseter (A) –Temporalis (B) –Pterygoid (C) have pt resist jaw opening during palpation

Question 40

what is the most common disorder of CN V?

Answer 40

Trigeminal Neuralgia (tic douloureux)

Question 41

Trigeminal Neuralgia (tic douloureux) what is it? what happens? cause

Answer 41

)Most common disorder of CN V) * Disease of PNS affecting the trigeminal ganglion or nerve * No motor or sensory losses * Excruciating bursts of pain, usually in one of the three sensory distributions of CN V * No known cause but often triggered by use of jaw, yawning, hot and cold, light breeze on face Lets talk about lesions to the trigeminal nerve. First Trigeminal Neuralgia (tic douloureux) is the Most common disorder of the trigeminal nerve. It is a condition of the PNS affecting the trigeminal ganglion or nerve. It involves Excruciating bursts of pain, usually in one of the three sensory distributions of CN V but with No motor or sensory losses. There is No known cause but often triggered by use of jaw, yawning, hot and cold, light breeze on face

Question 42

Herpes Zoster Ophthalmicus prevalance what happens?

Answer 42

another lesion of the Trigeminal nerve * 10-15% of all cases of herpes zoster * Inflammatory and infectious disease * 2–3 days of severe pain along distribution of the opthalmic division (V1) of CN V * Rash follows in this distribution * Can result in permanent corneal damage Herpes Zoster Ophthalmicus occurs in 10-15% of all cases of herpes zoster. It is a viral infectious disease accompanied by Inflammatory response around the nerve. It generally has the following symptoms 2–3 days of severe pain along distribution of the opthalmic division (V1) of CN V, Rash follows in this distribution and it can result in permanent corneal damage

Question 43

Wallenberg's syndrome what is another name for it? what causes it? what charecterizes it?

Answer 43

* •Also called lateral medullary syndrome * •Typically caused by a vascular lesion, occlusion of the posterior inferior cerebellar artery (PICA) * •Characterized by loss of pain and thermal sense in ipsilateral face and contralateral body due to damage of ascending spinal trigeminal and STT tracts Wallenberg's Syndrome is a vascular condition also called lateral medullary syndrome. It is Typically caused by a vascular lesion, specifically occlusion of the posterior inferior cerebellar artery (PICA). Wallenberg's Syndrome is Characterized by loss of pain and thermal sense in ipsilateral face and contralateral body due to damage of ascending spinal trigeminal axons and spinothalamic tracts because it affects the ascending Spinothalamic tracts that have already decussated and the spinal tract of V which carries axons which have not yet decussated

Question 44

What provides cortical control of the msucles of mastication?

Answer 44

the descending corticobulbar fibers (this will be discussed more in the future)