Biomaterial Database

[Masticatory muscles. Part VIII. Reflexes in the masticatory system]. 1998

H W van der Glas, and F Bosman, and A van der Bilt

Vakgroep Mondziekten, Kaakchirurgie en Bijzondere Tandheelkunde van de Universiteit Utrecht.

A reflex is an involuntary response on a specific nerve stimulus. Several types of receptors are present in the masticatory system which can be involved in reflex activity. A short mechanical tap on an incisor, for example, evokes a specific pattern of several so-called exteroceptive reflexes in the electromyographic (EMG) activity of jaw-closing muscles, which includes periods with decreased activity (inhibitory reflex) as well as increased activity (excitatory reflex). In this case, periodontal mechanoreceptors are detecting the stimulus. The second type of reflex that is dealt with is the jaw-jerk reflex as an example of a proprioceptive reflex. A transient increase in length of a jaw-closing muscle, detected by length sensors (muscle spindles), evokes an excitatory reflex in the EMG. Dependent on the motor task, the amplitude of both reflexes is modified. The various reflex mechanisms play an important role in normal physiological functions such as posture control and chewing.

UI	MeSH Term	Description	Entries
D008410	Masticatory Muscles	Muscles arising in the zygomatic arch that close the jaw. Their nerve supply is masseteric from the mandibular division of the trigeminal nerve. (From Stedman, 25th ed)	Masticatory Muscle,Muscle, Masticatory,Muscles, Masticatory
D008465	Mechanoreceptors	Cells specialized to transduce mechanical stimuli and relay that information centrally in the nervous system. Mechanoreceptor cells include the INNER EAR hair cells, which mediate hearing and balance, and the various somatosensory receptors, often with non-neural accessory structures.	Golgi Tendon Organ,Golgi Tendon Organs,Krause's End Bulb,Krause's End Bulbs,Mechanoreceptor,Mechanoreceptor Cell,Meissner's Corpuscle,Neurotendinous Spindle,Neurotendinous Spindles,Receptors, Stretch,Ruffini's Corpuscle,Ruffini's Corpuscles,Stretch Receptor,Stretch Receptors,Mechanoreceptor Cells,Bulb, Krause's End,Bulbs, Krause's End,Cell, Mechanoreceptor,Cells, Mechanoreceptor,Corpuscle, Meissner's,Corpuscle, Ruffini's,Corpuscles, Ruffini's,End Bulb, Krause's,End Bulbs, Krause's,Krause End Bulb,Krause End Bulbs,Krauses End Bulb,Krauses End Bulbs,Meissner Corpuscle,Meissners Corpuscle,Organ, Golgi Tendon,Organs, Golgi Tendon,Receptor, Stretch,Ruffini Corpuscle,Ruffini Corpuscles,Ruffinis Corpuscle,Ruffinis Corpuscles,Spindle, Neurotendinous,Spindles, Neurotendinous,Tendon Organ, Golgi,Tendon Organs, Golgi
D009046	Motor Neurons	Neurons which activate MUSCLE CELLS.	Neurons, Motor,Alpha Motorneurons,Motoneurons,Motor Neurons, Alpha,Neurons, Alpha Motor,Alpha Motor Neuron,Alpha Motor Neurons,Alpha Motorneuron,Motoneuron,Motor Neuron,Motor Neuron, Alpha,Motorneuron, Alpha,Motorneurons, Alpha,Neuron, Alpha Motor,Neuron, Motor
D011434	Proprioception	Sensory functions that transduce stimuli received by proprioceptive receptors in joints, tendons, muscles, and the INNER EAR into neural impulses to be transmitted to the CENTRAL NERVOUS SYSTEM. Proprioception provides sense of stationary positions and movements of one's body parts, and is important in maintaining KINESTHESIA and POSTURAL BALANCE.	Labyrinthine Sense,Position Sense,Posture Sense,Sense of Equilibrium,Vestibular Sense,Sense of Position,Equilibrium Sense,Sense, Labyrinthine,Sense, Position,Sense, Posture,Sense, Vestibular
D012018	Reflex	An involuntary movement or exercise of function in a part, excited in response to a stimulus applied to the periphery and transmitted to the brain or spinal cord.
D004576	Electromyography	Recording of the changes in electric potential of muscle by means of surface or needle electrodes.	Electromyogram,Surface Electromyography,Electromyograms,Electromyographies,Electromyographies, Surface,Electromyography, Surface,Surface Electromyographies
D006801	Humans	Members of the species Homo sapiens.	Homo sapiens,Man (Taxonomy),Human,Man, Modern,Modern Man