Lower motor neuron

The Lower Motor Neuron (LMN) is a type of motor neuron that directly connects to muscles and is responsible for muscle contraction. It is part of the motor neuron system, which also includes the upper motor neuron (UMN). The LMN and UMN work together to control voluntary movements.

Anatomy

The LMN is located in the anterior horn of the spinal cord and in the brainstem. It has a long axon that extends from the spinal cord or brainstem to the muscle it controls. The point where the LMN connects to the muscle is called the neuromuscular junction.

Function

The main function of the LMN is to transmit signals from the UMN to the muscles. This signal transmission results in muscle contraction and movement. The LMN also plays a role in maintaining muscle tone and reflexes.

Clinical significance

Damage to the LMN can result in a variety of neurological disorders, including amyotrophic lateral sclerosis (ALS), spinal muscular atrophy (SMA), and poliomyelitis. Symptoms of LMN damage can include muscle weakness, muscle atrophy, and decreased reflexes.

See also

• Motor neuron
• Upper motor neuron
• Neuromuscular junction
• Amyotrophic lateral sclerosis
• Spinal muscular atrophy
• Poliomyelitis