A<unk>  (γ motor<unk> , also called<unk>  motoneuron, or fusimotor<unk> , is a type of lower motor<unk>  that takes part in the process of muscle contraction, and represents about 30% of (Aγ) fibers going to the muscle. Like alpha motor<unk> s, their cell bodies are located in the anterior grey column of the spinal cord. They receive input from the reticular formation of the pons in the brainstem. Their axons are smaller than those of the alpha motor<unk> s, with a diameter of only 5 μm. Unlike the alpha motor<unk> s,<unk> s do not directly adjust the lengthening or shortening of muscles. However, their role is important in keeping muscle spindles taut, thereby allowing the continued firing of alpha<unk> s, leading to muscle contraction. These<unk> s also play a role in adjusting the sensitivity of muscle spindles. The presence of myelination in<unk> s allows a conduction velocity of 4 to 24 meters per second, significantly faster than with non-myelinated axons but slower than in alpha motor<unk> s.
Gamma motor neuron
Upper motor neuron
Muscle spindle
Nociceptor
Cerebrospinal fibers
Postganglionic nerve fibers
Efferent nerve fiber
Sensory nerve