The Heart

Cells are grouped into tissues and tissues are grouped into organs.

  • Pulmonary artery – carries deoxygenated blood from heart to lungs
  • Vena cava – brings deoxygenated blood from body to heart
  • Aorta – carries oxygenated blood from heart to body
  • Pulmonary vein – carries oxygenated blood from lungs to heart


The left ventricle is thicker than the right ventricle as it pushes blood all around the body.