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.
Definition of Motor Unit. A motor unit consists of one somatic efferent (motor) neuron and all of the muscle fibers (cells) that it innervates. In the figure to the right, two motor units are illustrated diagrammatically.Notice that after an efferent axon enters the muscle, it branches and forms synapses with a number of muscle fibers. motor unit consists of one somatic efferent (motor) neuron and all of the muscle fibers (cells) that it innervates.