When there is no measurable activity in the brain and the brainstem, this is called brain death. In a person who has been declared brain dead, removal of breathing devices will result in cessation of breathing and eventual heart failure. Brain death is considered irreversible.
The functional unit of a skeletal muscle is called a sarcomere. Hole's Anatomy 12th edition, pg 287 states: Muscle fibers, and in a way muscles themselves, are basically collections of sarcomeres, discussed later in this chapter as the functional units of muscle contraction.. sarcomere. Tina Wright.
The functional characteristics of a skeletal muscle cell : The cell membrane is called the sarcolemma. This membrane is structured to receive and conduct stimuli. The sarcoplasm of the cell is filled with contractile myofibrils and this results in the nuclei and other organelles being relegated to the edge of the cell.