Motor Units
A single motor neuron may synapse with one or more muscle fibers. The motor neuron and all of the muscle fibers to which it connects is a motor unit. Motor units are split up into 3 categories: slow motor units, fast fatiguing motor units, and fast fatigue-resistant motor units.
- Slow motor units are used to stimulate small muscle fibres which contract very slowly and provide small amounts of energy but are very resistant to fatigue, so they are used to sustain muscular contraction such keep the body upright.
- The Fast Fatiguing motor units are used to stimulate larger muscle groups which apply large amounts of force but fatigue very quickly. They are used for tasks that requires large brief bursts on energy such as jumping or running.
- The Fast Fatigue-Resistant motor unit stimulate moderate sized muscles groups that don't react as fast as the FF motor units, but can be sustained much longer, as implied by the name, and provide more force that the S motor unit.
Read more about this topic: Motorneuron
Famous quotes containing the words motor and/or units:
“This biplane is the shape of human flight.
Its name might better be First Motor Kite.”
—Robert Frost (1874–1963)
“Even in harmonious families there is this double life: the group life, which is the one we can observe in our neighbour’s household, and, underneath, another—secret and passionate and intense—which is the real life that stamps the faces and gives character to the voices of our friends. Always in his mind each member of these social units is escaping, running away, trying to break the net which circumstances and his own affections have woven about him.”
—Willa Cather (1873–1947)