Adorable animal families that will make you aww. A brain stem stroke is a stroke which originates in the brain stem. Because the brain stem handles many of the body's basic life support functions, such as breathing and heart rate, a brain stem stroke can be fatal.
Muscle fibers are in turn composed of myofibrils. The myofibrils are composed of actin and myosin filaments, repeated in units called sarcomeres, the basic functional units of the muscle fiber.The sarcomere is responsible for the striated appearance of skeletal muscle, and forms the basic machinery necessary for muscle contraction.keletal muscle is made up of individual muscle cells or myocytes, known as muscle fibers. They are formed from the fusion of developmental myoblasts (a type of embryonic progenitor cell that gives rise to a muscle cell) in a process known as myogenesis.
muscle fiber. any of the cells of skeletal or cardiac muscle tissue. Skeletal muscle fibers are cylindrical polynuclear cells containing contracting myofibrils, across which run transverse striations, enclosed in a sarcolemma.