Oro-Facial Flashcards
What are the factors affecting taste perception?
Age Meals Hunger Smoking Obesity Pregnancy Cold/Flu/Allergies Disease Temperature Adaptation
What is the main component of umami taste?
L-Glutamate
What is the main component of bitter tastes?
Alkaloids
Sensory pathways for taste in the epiglottis and larynx is innervated by what cranial nerve?
CN X: Vagus
Glossopharyngeal nerve provides taste to what?
Posterior 1/3 of tongue and pharynx
Where do taste signals terminate in the brain?
Gustatory Cortex (Anterior Insulafrontal Operculum)
What are the two measurements for taste acuity?
Detection and Recognition Threshold
T/F Sweet taste is pleasant at low concentrations
False
What is the life span of sustentacular + taste cells?
1-2 weeks
What is the implication of taste for obese people?
Less taste cells > compromised fat sensing system > delays satiety response > excess food intake
What is the difference between ageusia and dysgeusia?
Ageusia: total loss of taste
Dysgeusia: partial loss of taste
Damage to the chorda tympani will result in unilateral or contralateral loss of taste?
Unilateral loss of taste to anterior 2/3rd of the tongue
What can’t the Gates Control Theory explain?
Phantom Pain
T/F: Tonic Receptors are fast adapting
F: Slow Adapting
What are 5 things chemoreceptors can detect?
Taste / Smell / pH (H+) / Plasma O2 / Osmolality
What do Teleceptors detect and give 2 examples
Teleceptors are sensitive to stimuli originating at a distance. Such nerve endings exist in the eyes and ears.
Interoceptors can be found where?
Inside the body, in muscles, tendons and joints such as Muscle Spindles or the TMJ
Where in the Dorsal Column do neurons cross over?
Decusation of Media Leminscus in the medulla oblongata
Where do neurons cross over in the Spinothalamic Tract?
Within the spinal column where the 1st order neuron exists
What sort of sensory input can be found from nerves in the dorsal column?
Fine touch + pressure, vibration, position sensations
What sort of sensory input can be found from nerves in the spinothalamic tract?
Pain, Temperature, Crude Touch/Pressure, Tickle/Itch, Sexual sensations
What is meant by Somatic Sensory Projection?
Body parts represented in the brain is proportional to it’s importance for that species.
Eg: for humans sensory input from fingers + tongue is paramount for speech and fine motor skills
Meissner Corpuscle measure what sensory input?
Dynamic Deformation
Hair Follicles measure what sensory input?
Light Touch
Pacinian Corpuscle measure what sensory input?
Vibration
Merkel Cell measure what sensory input?
Indentation & Depth
Ruffini Corpuscle measure what sensory input?
Stretch
C-Fibre LTM measure what sensory input?
Touch
Mechano-Nociceptor Polymodal Mechano-Nociceptors measure what sensory input?
Injuring Forces
What is meant by Tactile Acuity?
Two points of contact are felt as two distinct points
Can Tactile Acuity cross the midline?
No
What are some examples of Tactile Acuity
Tongue, Finger Tip, Nose
What mucosa in the oral cavity can detect both cold and warm?
Dorsum of Tongue (Strong Both) Ventral Tongue (Moderate Warm/Strong Cold) Labial Mucosa (Moderate Both)
What is the role of Periodontal Mechanoreceptors?
Oral Stereognosis and tactile sensitivity to teeth
What factors affect Oral Stereognosis Ability (OSA)?
- Form, Size and Surface characteristics of the test piece
- Presentation order of the objects
- Age
- Dental Status (poorer with missing dentition, perio, endo treated teeth)
- Duchenne Muscular Dystrophy
Why is Oral Stereognosis important?
For efficient mastication that does not damage hard / soft tissue
Stomatodynia is also known as what?
Burning Mouth Syndrome
What are endogenous mediators of pain for nociceptors?
Bradykinin, H+, Substance P, Histamine, K+
What fibres result in fast pain?
A-Delta Fibres
What is double pain sensation?
A-Delta + C Fibres which conduct the impulses at different velocities
In an inflammatory response what does bradykinin do in terms of pain?
Activates nociceptors
What is Central Sensitisation?
Where the nervous system winds up during a persistent state of high reactivity to pain in order to develop a response to maintain chronic pain. This results in the patient being more sensitive not only to pain but to other sensory input.
What is the role of Substance P during the inflammation of dental pulp?
Vasodilatory Response Histamine Release Increase in blood flow + vascular permeability Increase in blood pressure Synthesis of proinflammatory cytokines Chemotaxis of inflammatory cells Sensitisation of nociceptors
What can modulate pain from ascending pain transmitting tracts?
Endogenous Opiates from Inhibitory interneurons in the dorsal horn
Are A-Beta fibres part of a pain response?
No.
They are large myelinated fibres involved with touch, pressure and proprioception
What are Von Ebner’s Glands and where are they found?
Serous salivary secretion glands found on the lateral surface of Circumvallate Papillae
If a patient is clinically observed with a lack of Filliform Papillae and a bold red appearance, what could this be a sign of?
Low Iron levels in the blood
Where can minor taste organs be found?
Soft + Hard Palate
Pharynx
Larynx
Epiglottis
What is the difference between detection and recongition threshold?
Detection Threshold: the ability to distinguish a taste apart from a drop of water
Recognition Threshold: the concentration needed for a solution to be identified as having a certain taste
Why does xerostomia result in poor taste
Poor saliva results in insufficient solution to transport
What are 3 main reasons for taste disorders?
- Transport Loss (Xerostomia)
- Sensory Loss (Injury to receptor cells)
- Neural Loss ( gustatory afferent nerves + central gustatory pathways)
What are 4 key criteria for the detection of olfactory stimuli?
- Must by volatile - sensitive to changing stimulus
- Sufficiently water soluble
- Must be lipid soluble
- Minimum number of odorous particles must be present for a minimum length of time
What are the 3 phases of the masticatory cycle?
- Opening Phase (Slow > Fast)
- Closing Phase (Fast > Slow)
- Occlusal Phase
What masticatory features would you expect to see in a true carnivore?
- Cylindric TMJ for strong biting hinge movement
- Sharp Teeth
- Fast Muscles
- Dominant Temporalis
What masticatory features would you expect to see in a true herbivore?
- Saucer like TMJ for grinding fibrous food
- Flat Teeth
- Slow Muscles
- Dominant Masseter
What is the role of the Orbicularis Oris in mastication?
To provide an anterior oral seal around the lips
Accessory muscles of mastication Sternohyoid, Sternothyroid, Omohyoid are innervated by what?
C1–C3 Ansa cervicalis