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.
A motor neuron (or motoneuron) is a nerve cell (neuron) whose cell body is located in the spinal cord and whose fiber (axon) projects outside the spinal cord to directly or indirectly control effector organs, mainly muscles and glands.here are upper motor neurons and lower motor neurons, with the cell type described above being a lower motor neuron. Upper motor neurons are cortico-spinal interneurons that arise from the motor cortex and descend to the spinal cord where they activate the lower motor neurons through synapses.