Final answer:
The five mechanisms that keep venous blood moving toward the right atrium are one-way valves, skeletal muscle pump, respiratory pump, vascular tone, and vasoconstriction. These valves prevent the backflow of blood in the veins and ensure that blood moves in one direction towards the heart.
Step-by-step explanation:
The five mechanisms that keep the venous blood moving toward the right atrium are:
- One-way valves: These valves prevent the backflow of blood in the veins and ensure that blood moves in one direction towards the heart.
- Skeletal muscle pump: Contraction of skeletal muscles surrounding the veins helps push the blood towards the heart. When the muscles contract, they squeeze the veins and help propel the blood forward.
- Respiratory pump: During inhalation, there is an increase in abdominal pressure, which compresses the veins in the abdomen and helps move blood towards the heart.
- Vascular tone: Maintaining the proper tone or constriction of the veins helps prevent them from distending and dampening the flow of blood.
- Vasoconstriction: Constriction of the veins enhances blood flow and increases venous return to the heart.