Unused muscles atrophy.
The muscles will atrophy (shrink) if not used.
you excersise
They contract
well , total paralysis on one side of body is called hemiplegia...... where as weakness is called paraplegia..... these may be due to damage at the brain or spinal cord...
you will die
you exhale (:
contrast
What happens when a muscle shortens is that it is contracting. This is when the fibers of the muscles generate tension.
muscles relaxes
Im not expert, but isn't it the diaphragm and rib muscles, the muscles between the ribs, internal and external intercostals.
Atrophy
Movement