EX1; Trigeminal System Flashcards by Courtney Kast

What is the functional significance of the trigeminal system

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

How well did you know this?

Not at all

Perfectly

What is stereognosis regarding the trigeminal system

3-dimensionality of objects in the mouth

size, texture, hardness

How well did you know this?

Not at all

Perfectly

what is flavor regarding the trigeminal system

taste and olfaction (special senses)

texture, temperature, chemesthesis

How well did you know this?

Not at all

Perfectly

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

How well did you know this?

Not at all

Perfectly

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

How well did you know this?

Not at all

Perfectly

What are the three main branches of trigeminal

opthalmic
maxillary
mandibular

How well did you know this?

Not at all

Perfectly

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

mandibular

How well did you know this?

Not at all

Perfectly

Where are the cell bodies for the trigeminal nerve located

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

How well did you know this?

Not at all

Perfectly

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

How well did you know this?

Not at all

Perfectly

The ascending branch of trigeminal ends where

in the principal nucleus

How well did you know this?

Not at all

Perfectly

What is the function of the ascending branch of trigeminal

light touch perception

How well did you know this?

Not at all

Perfectly

The descending branch of trigeminal ends where

in the spinal trigeminal nucleus

How well did you know this?

Not at all

Perfectly

What are the three divisions of the spinal trigeminal nucleus

nucleus oralis
nucleus interpolaris
nucleus caudalis

How well did you know this?

Not at all

Perfectly

What is the function of nucleus oralis

light touch perception

How well did you know this?

Not at all

Perfectly

What is the function of nucleus interpolaris

temperature perception

How well did you know this?

Not at all

Perfectly

What is the function of nucleus caudalis

pain perception

How well did you know this?

Not at all

Perfectly

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

How well did you know this?

Not at all

Perfectly

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

How well did you know this?

Not at all

Perfectly

What are the two types of rapidly adapting mechanoreceptors

small receptive fields

large receptive fields

How well did you know this?

Not at all

Perfectly

What are the two types of slowly adapting mecahnoreceptors

small receptive fields

large receptive fields

How well did you know this?

Not at all

Perfectly

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

How well did you know this?

Not at all

Perfectly

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

epithelial NaCl channels; ENac

How well did you know this?

Not at all

Perfectly

Mechanical transduction may occur through which specific channels

transient receptor potential channels

How well did you know this?

Not at all

Perfectly

In the hand, there is a correlation between receptor what

structure and function

How well did you know this?

Not at all

Perfectly

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

skin stretch

The pacinian corpuscle is involved with what sensation

vibration

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)

The Meissner corpuscle is involved with what sensation

light touch/spatial discrimination

The merkel receptor is involved with what sensation

pressure

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

pacinian

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

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

an off-response to the receptor

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

von frey hairs

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

facial midline

Oral and facial tissues show specialized patterns of what

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

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

microneurography

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

True

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)

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

lingual nerve

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

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

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

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

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

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

What branches of mandibualr; trigeminal innervate TMJ

auriculotemporal masseter posterior deep temporal

Where is the most dense innervation of TMJ

posterior and lateral portion of capsule

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

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

midline teeth

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

What nerve innervate the PDL

branches of superior and inferior alveolar nerves

What type of nerve ending is found in the PDL

unencapsulated Ruffini type endings

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

trigeminal ganglion | mesencephalic nucleus

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

distal direction

These specific fibers also show directional sensitivity

rapidly adapting

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

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

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

mesencephalic trigeminal nucleus

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

it becomes shorter

clincial conditions such as periodontitis can increase what of PDL

increase thresholds (lower sensitivity)

The location of what in the PDL determines sensitivity

Ruffini endings

Denture and implant patients have trouble with force regarding what

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

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

wide

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

less

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

cold or warm

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

TRP (transient receptor potential)