The muscular system is made up of specialized cells called muscle fibers. Their main function is contractibility. Muscles, connected to bones or internal organs and blood vessels, are in charge for movement. Almost every movement in the body is the outcome of muscle contraction.
The trillions of cells in the body require an abundant and continuous supply of oxygen to carry out their vital functions. We cannot “do without oxygen” for even a little while, as we can without food or water.