[Masticatory muscles. Part VIII. Reflexes in the masticatory system].
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.
van der Glas
H W
HW
Vakgroep Mondziekten, Kaakchirurgie en Bijzondere Tandheelkunde van de Universiteit Utrecht.
Bosman
F
F
van der Bilt
A
A
D004576:Electromyography; D006801:Humans; D008410:Masticatory Muscles / Q000294:innervation* / Q000502:physiology*; D008465:Mechanoreceptors / Q000502:physiology; D009046:Motor Neurons / Q000502:physiology; D011434:Proprioception / Q000502:physiology; D012018:Reflex / Q000502:physiology*
Kauwspieren. Deel. VIII. Reflexen in het kauwstelsel.