Normally, the coordinated action of the muscles of the stomach and small intestine propels the food from the stomach, through the small intestine and into the colon. This muscular action also sweeps bacteria out of the small intestine and limits the numbers of bacteria in the small intestine.
The term 'motor neuron' is usually restricted to the efferent neurons that actually innervate muscles (the lower motor neurons). A single motor neuron may innervate many muscle fibres and a muscle fibre can undergo many action potentials in the time taken for a single muscle twitch.
The motor neuron diseases (MNDs) are a group of progressive neurological disorders that destroy motor neurons, the cells that control essential voluntary muscle activity such as speaking, walking, breathing, and swallowing.pper motor neurons direct the lower motor neurons to produce movements such as walking or chewing. Lower motor neurons control movement in the arms, legs, chest, face, throat, and tongue. Spinal motor neurons are also called anterior horn cells. Upper motor neurons are also called corticospinal neurons.