Functional identification of the perioral neuromuscular system: a signal flow diagram

The components of a neuromuscular system are identified, and anatomical and physiological features of the elements are organized into a signal flow diagram. The elements of the perioral neuromuscular system are described in the context of the system flow diagram developed for a generalized neuromuscular system. Important features of commonality and contrast between limb and perioral systems, and areas of needed research are emphasized. Features of contrast include geometry and insertions of muscles, relative influence of inertial loads, and organization of inputs to motoneurons.