Human Biology 175-Chapter 6-True/False
Excessive stretching of a muscle may result in a torn muscle a) True b) False
a) True
In addition to producing or resisting movement, an important function of muscle is generation of heat. a) True b) False
a) True
Muscle contraction cannot occur without the presence of calcium in the cytoplasm of the muscle fiber. a) True b) False
a) True
Muscle cramps are helped by massage and stretching, which increase blood flow to the affected area. a) True b) False
a) True
Muscle fibers (muscle cells) are filled with myofibrils which in turn are filled with the contractile filaments myosin and actin. a) True b) False
a) True
Muscle groups that work together to create the same movement are called synergistic muscles. a) True b) False
a) True
Muscle relaxation requires ATP. a) True b) False
a) True
Oxygen debt occurs when a muscle uses more ATP than aerobic metabolism can provide. a) True b) False
a) True
The end of a skeletal muscle attached to a bone that does not move during contraction is called the origin. a) True b) False
a) True
Neither aerobic training nor strength training will lead to an increase in the number of muscle fibers in a given muscle. a) True b) False
a) True Note: Aerobic training builds endurance by increasing the oxygen usage by a muscle fiber and strength training increases muscle mass, but neither affects the number of muscle fibers, which is determined by heredity.
Cardiac muscle fibers are joined in a way that allows the cells to activate each other, and do not require stimulation by a neuron. a) True b) False
a) True Note: Though skeletal muscle fibers must be stimulated by a neuron, cardiac muscle fibers and smooth muscle fibers can be activated by other cells of the same tissue.
Acetylcholine is a neurotransmitter released by motor neurons that causes skeletal muscle fibers to relax. a) True b) False
b) False
In the sliding filament mechanism, myosin filaments are pulled across stationary actin filaments to contract the muscle. a) True b) False
b) False
Isometric contractions result in generation of force, increase of muscle tension, and movement of a body part. a) True b) False
b) False
A motor unit consists of one muscle cell and all the motor neurons that stimulate that muscle cell. a) True b) False
b) False Note: A motor unit is composed of one motor neuron and all of the muscle fibers (cells) that it stimulates.
