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.
motor neuron, one of various efferent nerve cells that transmit nerve impulses from the brain or from the spinal cord to muscular or glandular tissue. According to location, some kinds of motor neurons are the peripheral motor neurons and the upper motor neurons. Also called motoneuron.. (type II): stellate neurons with short axons in the cerebral and cerebellar cortices and in the retina. motor neuron motoneuron. postganglionic n's neurons whose cell bodies lie in the autonomic ganglia and whose purpose is to relay impulses beyond the ganglia.