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.
A muscle fiber consists of a bundle of muscle myofibrils. 4. muscle myofibril = contains thousands of sarcomeres-sometimes as many as 10,000 sarcomere units end-to-end. 5. sarcomere = is the functional unit of a muscle contraction because it is this structure that actually shortens during a contraction.