The Canadian Pacific Railway (CPR), formerly also known as CP Rail (reporting mark CP) between 1968 and 1996, is a historic Canadian Class I rail carrier founded in 1881 and now operated by Canadian Pacific Railway Limited (TSX: CP, NYSE: CP), which began operations as legal owner in a corporate restructuring in 2001.nder the initial contract with the Canadian government to build the railway, the CPR was granted 25 million acres (100,000 km 2). Proving already to be a very resourceful organization, Canadian Pacific began an intense campaign to bring immigrants to Canada.
During exercise, cardiac output can increase, as much as eight-fold in world-class endurance athletes. If exercise is performed in the upright position, returning blood to the heart at this rate is challenging because the pull of gravity provides opposition.
Valves and Blood Return to the Heart. Because up to 65% of the body s total blood volume is found in the veins at any time, and because the blood pressures in veins are low, the body needs some special adaptations to help return blood to the heart. These include: 1  Large diameter of the lumens. 2  The presence of one-way valves to prevent blood from flowing backward. 3  Contracting skeletal muscles that press against veins to force blood through these one-way valves.