Discriminative Somesthesis Flashcards
Afferent nerves supplying the periodontal tissues (periodontal ligament, gingiva, and attached mucosa) are the peripheral processes of ______ and _______ neurons that course in the _______
trigeminal ganglion; trigeminal mesencephalic; maxillary and mandibular divisions of the trigeminal nerve
Receptors in the periodontal ligament consist of several types of modified _____ and a variety of free nerve endings
Ruffini nerve endings
The ______ are associated with larger myelinated nerve fibers and they are exquisitely sensitive to changes in forces applied to the teeth
Ruffini endings
The Ruffini endings, very prominently associated with the periodontal ligaments, are ________, as they are in skin
slowly adapting mechanoreceptors
What are the 3 functions of periodontal mechanoreceptors?
- Tactile sensibility of the teeth
- Discrimination of size, shape, texture and hardness of foodstuff or other objects placed in the mouth
- Reflex motor control of the muscular movement of the mandible including mastication
Threshold sensitivity is often tested with ______.
monofilaments (originally, von Frey hairs)
____ varies across the body and is determined by sensitivity of rapidly adapting mechanoreceptors, although perception of pressure per se is mediated by slowly adapting mechanoreceptors
Threshold sensitivity
____ is the measure of spatial resolution of touch.
Tactile acuity
What is the most common way to test tactile acuity?
tow point threshold
____ are the most sensitive to vibration, particularly in the 100-400Hz range.
Pacinian corpuscles
Perceptual Correlate: Detecting skin contact; low frequency vibration; shape movement across skin
Mechanoreceptor Type: Meisnner - FAI (RAI)
Perceptual Correlate: Static pressure on skin; object shape, both static and moving
Mechanoreceptor Type: Merkel - SAI
Perceptual Correlate: Detecting abrupt skin contact; high frequency vibration
Mechanoreceptor Type: Pacinian - FAII (also RAII or PC)
Perceptual correlate: tissue stretch
Mechanoreceptor: Ruffini - SAII
Electrical Stimulation: Pressure, but no sense of contact
Mechanoreceptor Type: Merkel - SAI
Electrical Stimulation: Tapping
Mechanoreceptor Type: Meisnner - FAI (RAI)
Electrical Stimulation: Buzzing
Mechanoreceptor Type: Pacinian - FAII (also RAII or PC)
In general, mechanoreceptors in orofacial tissues, including oral mucosa and the tongue resemble ____, _____, and to a lesser extent, _____ afferents in the skin of the hand
FAI, SAI, SAII
Collectively, the mechanoreceptors in oral and perioral tissues are stimulated by _____ of their receptive fields
mechanical strain
Ligamentous fibers (LF) of the PDL are innervated by _____ and _____ afferent fibers
mechanoreceptive; nociceptive
Mechanoreceptive endings resemble ______ found in dermis, and respond to stretching of the ligaments associated with forces applied to the tooth
Ruffini cylinders
Meissner’s corpuscles and Merkel’s receptors have the pattern that best matches the pattern for _____
tactile spatial acuity
