the circulatory system

• Single-celled organisms such as protists and small multicellular organisms


  • Essential molecules move to where they're needed by diffusion
• Transport system


  Needed by organisms beyond a certain size (e.g. very early embryo) to distribute essential molecules efficiently
• The heart is located between the lungs, behind the sternum (breastbone), and to the left side.
• The heart has four chambers - two atria and two ventricles.
• Transport systems


  • Made up of tubes or 'vessels' that carry materials from one part of the organism to another
  • Make close contact with cells, such as those of exchange surfaces
• where is glucose transported from and where does it go to?


  Transported from digestive system to the liver then all the cells in the body
• where is carbon dioxide transported from and where does it go to?

  transported from all of the bodies cells to the lungs
• where is urea transported from and where does it go to?

  transported from liver to the kidneys
• where is oxygen transported from and where does it go to?

  transported from the lungs to all the bodies cells
• in the blood, where is oxygen carried?


  Haemoglobin in the red blood cells
• in the blood, where are dissolved substances carried?

  Plasma