Search results
Results from the WOW.Com Content Network
Schematic representation of patellar tendon reflex (knee jerk) pathway. The patellar reflex, also called the knee reflex or knee-jerk, is a stretch reflex which tests the L2, L3, and L4 segments of the spinal cord. Many animals, most significantly humans, have been seen to have the patellar reflex, including dogs, cats, horses, and other ...
A list of reflexes in humans. Abdominal reflex; Accommodation reflex — coordinated changes in the vergence, lens shape and pupil size when looking at a distant object after a near object. Acoustic reflex or attenuation reflex — contraction of the stapedius and tensor tympani muscles in the middle ear in response to high sound intensities.
The Jendrassik maneuver to reinforce knee-jerk. The Jendrassik maneuver is a medical maneuver wherein the patient clenches the teeth, flexes both sets of fingers into a hook-like form, and interlocks those sets of fingers together. The tendon below the patient's knee is then hit with a reflex hammer to elicit the patellar reflex. The elicited ...
The stretch reflex (myotatic reflex), or more accurately "muscle stretch reflex", is a muscle contraction in response to stretching a muscle. The function of the reflex is generally thought to be maintaining the muscle at a constant length but the response is often coordinated across multiple muscles and even joints. [ 1 ]
In biology, a reflex, or reflex action, is an involuntary, unplanned sequence or action [1] and nearly instantaneous response to a stimulus. [2] [3] The simplest reflex is initiated by a stimulus, which activates an afferent nerve. The signal is then passed to a response neuron, which generates a response.
Like the knee jerk reflex, the Lazarus sign is an example of a reflex mediated by a reflex arc—a neural pathway which passes via the spinal column but not through the brain. As a consequence, the movement is possible in brain-dead patients whose organs have been kept functioning by life-support machines , precluding the use of complex ...
It can be detected through the use of a reflex hammer and is the opposite of hyperreflexia. [ citation needed ] Hyporeflexia is generally associated with a deficit in the lower motor neurons (at the alpha motor neurons from the spinal cord to a muscle), whereas hyperreflexia is often attributed to lesions in the upper motor neurons (along the ...
Most reflexes can be categorized in one of three groups depending on the latency of EMG response. The short-latency reflex (SLR) is the fastest (~40-50 ms) and involves a mono-synaptic pathway. The medium-latency reflex (MLR) utilizes interneurons within the spinal cord and is typically ~80-90 ms. The long-latency reflex (LLR) is ~120-140 ms ...