Ad blocker interference detected!
Wikia is a free-to-use site that makes money from advertising. We have a modified experience for viewers using ad blockers
Wikia is not accessible if you’ve made further modifications. Remove the custom ad blocker rule(s) and the page will load as expected.
Individual differences |
Methods | Statistics | Clinical | Educational | Industrial | Professional items | World psychology |
Biological: Behavioural genetics · Evolutionary psychology · Neuroanatomy · Neurochemistry · Neuroendocrinology · Neuroscience · Psychoneuroimmunology · Physiological Psychology · Psychopharmacology (Index, Outline)
The jaw jerk reflex or the masseter reflex is a stretch reflex used to test the status of a patient's trigeminal nerve (CN V). The mandible—or lower jaw—is tapped at a downward angle just below the lips at the chin while the mouth is held slightly open. In response, the masseter muscles will jerk the mandible upwards. Normally this reflex is absent or very slight. However in individuals with upper motor neuron lesions the jaw jerk reflex can be quite pronounced.
As with most other reflexes, the response to the stimulus is monosynaptic, with sensory neurons of the trigeminal mesencephalic nucleus sending axons to the trigeminal motor nucleus, which in turn innervates the masseter. This reflex is used to judge the integrity of the upper motor neurons projecting to the trigeminal motor nucleus. Both the sensory and motor aspects of this reflex are through CN V.
- Nolte, J. The Human Brain, 5th ed. Mosby: Missouri; 2002, p.307. ISBN 0-323-01320-1
- Blumenfeld, H. Neuroanatomy Through Clinical Cases. Sinauer Associates: Massachusetts; 2002, p. 484. ISBN 0-87893-060-4
Nervous system physiology: neurophysiology - reflex
|This page uses Creative Commons Licensed content from Wikipedia (view authors).|