Circulatory System

• The components of blood are plasma, red blood cells, white blood cells and platelets.
• Red blood cells contain haemoglobin, which is a molecule specially designed to hold oxygen and carry it to cells that need it.
• Arteries carry blood away from the heart.
• Veins carry blood back to the heart
• Capillaries are tiny vessels which carry blood into organs and tissues.
• Arteries are thick with a narrow diameter.
• Veins are thin with a large diameter.
• The circulatory system carries blood and dissolved substances to and from different places in the body.
• The heart and blood vessels together make up the circulatory system.
• The heart pumps blood around your body as your heart beats.
• The four chambers of the heart are the right ventricle, right atrium, left ventricle and left atrium.
• The pathway of blood through the heart is the vena cava, right atrium, right ventricle, pulmonary artery, lungs, pulmonary vein, left atrium, left ventricle, aorta and body.
• Exercise changes heart rate so that more blood can get to your body.