Descartes

Charles Sherrington at 50

Sherington’s Physiology, c1900-1945

A pool of motor neuronsIn the spinal cordServes each muscle

These pools form aTopographic map(sort of)

Sherrington’s Conceptual masterpieceThe Stretch Reflex

The sensory element:

The Stretch Reflex Circuit

Another View of theStretch Reflex

Note that some other systemHas to set the initial positionOf the limb

The Crossed ExtensionReflex

•Involves excitation andInhibition•Activates muscles onboth sides of body