The Arkansas Railroad Museum preserves the last steam-powered locomotive built in Arkansas and includes various artifacts of Arkansasâs railroad heritage. The Pine Bluff/Jefferson County Historical Museum opened in 1980 in the restored 1907 Union Pacific train depot.
myasthenia gravis. An autoimmune disease affecting neuromuscular junctions characterized by muscle weakness and fatigability. It is due to a destruction of acetylcholine receptors in the postsynaptic membrane of the neuromuscular junction.
1 Motor neuron diseases--a group of progressive, degenerative nerve disorders that includes amyotrophic lateral sclerosis (ALS, or Lou Gehrig's disease)  Diseases of the neuromuscular junction such as myasthenia gravis, a chronic but highly treatable condition causing weakness in the voluntary muscles.