Lower Motor Neuron- MedFriendly.com

A lower motor neuron (often abbreviated LMNs) is the

part of a motor neuron (a type of nerve cell) that

connects the brainstem and spinal cord (via the upper

motor neurons) to the skeletal muscles. The brainstem

is an area in the lower part of the brain that connects it

with the spinal cord.

FEATURED BOOK: Principles of Neurology by Adams and Victor

Skeletal muscles are muscles that are connected at either or both arms or legs with the

skeleton of the body. Upper motor neurons are nerve cells in the motor cortex (an area of

the brain located in middle, top part of the brain) that help make up nerve paths within the

brain and from the brain to the spine.

Lower motor neurons are present in the spinal nerves, peripheral nerves (nerves outside

of the brain or spinal cord), and anterior horn cells. Anterior horn cells are types of cells

located in the spinal cord.

Damage to lower motor neurons can cause lower motor neuron paralysis, in which loss of

movement/and or sensation can occur in addition to a loss of certain reflexes and the

occurrence of various other signs and symptoms such as decreased muscle tone,

weakness, fasciculations (small involuntary muscle contraction), decreased reflexes, and

muscle atrophy.