MUSCLE PHYSIOLOGY

Detailed explanation-1: -A motor unit is made up of a motor neuron and all of the skeletal muscle fibers innervated by the neuron’s axon terminals, including the neuromuscular junctions between the neuron and the fibres. Groups of motor units often work together as a motor pool to coordinate the contractions of a single muscle.

Detailed explanation-2: -Small motor neurons innervate relatively few muscle fibers and form motor units that generate small forces, whereas large motor neurons innervate larger, more powerful motor units. Motor units also differ in the types of muscle fibers that they innervate.

Detailed explanation-3: -A motor unit consists of the motor neuron and the grouping of muscle fibers innervated by the neuron.

Detailed explanation-4: -Remember that a muscle fiber is the same thing as a muscle cell. A single efferent neuron typically controls multiple muscle fibers, and there are many many neurons that control different muscle fibers in a single muscle. A single efferent neuron and all of the muscle fibers that it controls is called a motor unit.

Detailed explanation-5: -Each muscle fiber is innervated by only one motor neuron. The actual group of muscle fibers in a muscle innervated by a single motor neuron is called a motor unit.