Circulation Notes

Cardiovascular System – This system carries needed substances (food & oxygen) to cells and carries waste products away from the cells. (Blood also helps fight diseases)

Blood vessels

Arteries – carry blood away from the heart.

Veins – carry blood to the heart.

Capillaries – tiny blood vessels where substances are exchanged by diffusion.

The Heart

Left side – Pumps oxygen-filled blood from the lungs to the

body. (This blood is referred to as “red”)

Right side – Pumps non-oxygen filled blood from the body to

the lungs. (This blood is referred to as “blue”)

Steps to Blood Flow

  1. Blood enters the main vein from the upper and lower body. (Vena Cava)
  1. Blood then moves to the right atrium. This blood is low in oxygen and high in CO2 (blue- since it comes from the body).
  2. Blood now moves through a valve to the right ventricle where it is pumped to the lungs. It goes out of the heart through the pulmonary artery.
  1. Blood is now in the lungs and getting new oxygen!
  1. Blood now leaves the lungs and enters the heart through the pulmonary vein and travels to the left atrium. This blood is high in oxygen and is “red”.
  1. Blood now moves through a valve and enters the left ventricle. The left ventricle pumps the blood out of the heart through the aorta. (Artery) The blood is sent to the upper and lower parts of the body to spread the fresh oxygenated blood to your cells.

Review of Blood Flow

*** You may start anywhere in the steps of blood flow. Remember it is a cycle that continues over and over again.

  1. Vena Cava – main vein from the body to the heart
  2. Right Atrium
  3. Right Ventricle
  4. Lungs – enters and exits through the pulmonary artery and the pulmonary vein.
  5. Left Atrium
  6. Left Ventricle
  7. Aorta – main artery from the heart to the body.