Why can red blood cells move quickly through blood vessels?

Answer 1

• 1) the deoxygenated red blood cell travels back to the heart in the vena cava
• 2) it enters the right atrium
• 3) the right atrium contracts and pushes it through the tricuspid and into the right ventricle,
• 4) the right ventricle contracts and pushes it out of the heart through the semi lunar,
• 5) it travels through the pulmonary artery to the lungs,
• 6) here it picks up oxygen,
• 7) it travels back to the heart through the pulmonary vein,
• 8) it enters the left atrium,
• 9) the left atrium contracts and pushes it through the bicuspid and into the left ventricle,
• 10) the left ventricle contracts and pushes it through the semi lunar out of the heart and into the Aorta.

Only because the heart pumps so well.

Answer 2

that pushes all the plasma through - otherwise you'd get laminar flow - and that would result in stagnant outer layers - and that would result in oxygen depletion in those layers closest to the tissues.