Muscle spindle
Mammalian muscle spindle showing typical position in a muscle (left), neuronal connections in spinal cord (middle), and expanded schematic (right). The spindle is a stretch receptor with its own motor supply consisting of several intrafusal muscle fibers. The sensory endings of a primary (group Ia) afferent and a secondary (group II) afferent coil around the non-contractile central portions of the intrafusal fibers.
This is a drawing of a mammalian muscle spindle showing its typical position in a muscle (left image), neuronal connections in spinal cord (middle image), and expanded schematic (right image). The spindle is a stretch receptor with its own motor supply consisting of several intrafusal muscle fibers. The sensory endings of a primary afferent and a secondary afferent can be seen coiled around the non-contractile central portions of the intrafusal fibers.
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"Muscle spindle model."
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