Final answer:
Blood in the legs travels against gravity to the heart with the help of the skeletal muscle pump, which relies on muscle contractions and one-way valves in the veins. Additional measures like wearing compression stockings can enhance this upward blood flow.
Step-by-step explanation:
Blood travels against gravity up the legs using a system known as the skeletal muscle pump. This mechanism increases the pressure within the veins through the contraction of surrounding skeletal muscles during activities such as walking or running. These muscles exert pressure on nearby veins that have one-way valves, allowing blood to flow upward. When the muscles contract, valves superior to the contracting muscles open, allowing blood to flow through, while valves inferior to the contracting muscles close to prevent blood from flowing backward. This prevents blood pooling in the lower limbs.
Using elastic bandages or tight stockings can also help by providing additional pressure, which aids in moving blood back to the heart, particularly when one is standing still for extended periods or on long-haul flights. Regular movement and avoiding long periods of immobility are essential to prevent the pooling of blood in the extremities, maintaining proper circulation.