Muscle Spindle · The Stretch Reflex
unseel.com · intrafusal fibers · Piezo2 · Ia afferent · monosynaptic loop
Loop latency ~30 ms
Ia firing 0 Hz
Phase
Intrafusal fiber (spindle)
Annulospiral Ia ending
Piezo2 channel · Na⁺/Ca²⁺
Alpha motor neuron · contraction
Gamma motor neuron
Unseel.com · Muscle Spindle and the Stretch Reflex