This simulator visualizes how stretching a muscle lengthens its embedded spindle, driving Ia afferent firing that scales with both stretch magnitude and velocity, and how that signal travels a monosynaptic spinal arc to trigger a corrective muscle contraction.
Apply a stretch to the simulated muscle by adjusting length and speed, then watch the spindle's Ia afferent firing rate and the resulting reflex contraction, including the effect of toggling gamma motor neuron activity on spindle sensitivity.
Sliders let you set stretch magnitude and stretch velocity while a toggle switches gamma motor neuron activity on or off to observe changes in spindle sensitivity and reflex response.
The patellar reflex loop is so fast, completing in about 30 to 50 milliseconds, that it is often used clinically as a quick check of spinal cord integrity without needing any input from the brain at all.
This simulator visualizes how stretching a muscle lengthens its embedded spindle, driving Ia afferent firing that scales with both stretch magnitude and velocity, and how that signal travels a monosynaptic spinal arc to trigger a corrective muscle contraction.
This simulator visualizes how stretching a muscle lengthens its embedded spindle, driving Ia afferent firing that scales with both stretch magnitude and velocity, and how that signal travels a monosynaptic spinal arc to trigger a corrective muscle contraction.
Apply a stretch to the simulated muscle by adjusting length and speed, then watch the spindle's Ia afferent firing rate and the resulting reflex contraction, including the effect of toggling gamma motor neuron activity on spindle sensitivity.
The patellar reflex loop is so fast, completing in about 30 to 50 milliseconds, that it is often used clinically as a quick check of spinal cord integrity without needing any input from the brain at all.