Of or pertaining to James the First, of England, or of his reign or times; especially, pertaining to a style of architecture and decoration popular in the time of James I.; as, Jacobean writers. Etymology: From L. Jacobus James.
ALS is a progressive, degenerative disease of the nervous system. It is one of a group of diseases, called motor neuron diseases (MND), in which specialized nerve cells that control movement of the voluntary muscles gradually cease functioning and die. Fasciculation is a sign of muscle irritability, as the normal action of the lower motor neuron on the muscle is impaired. 2  The sole involvement of lower motor neurons can be seen in a form of ALS called progressive muscular atrophy.
Atrophy is the general physiological process of reabsorption and breakdown of tissues, involving apoptosis.When it occurs as a result of disease or loss of trophic support due to other disease, it is termed pathological atrophy, although it can be a part of normal body development and homeostasis as well.stronauts in microgravity must exercise regularly to minimize atrophy of their limb muscles. There are many diseases and conditions which cause atrophy of muscle mass. For example diseases such as cancer and AIDS induce a body wasting syndrome called  cachexia , which is notable for the severe muscle atrophy seen.