Transport systems- animals

• The three main components of blood are:

  • red blood cells
  • white blood
  • plasma

  Blood transports nutrients, oxygen and carbon dioxide around the body
• Red blood cells are specialised to efficiently transport oxygen around the body

  Features of a red blood cell

  • have no nucleus -> more room for oxygen
  • biconcave shape -> increases surface area for oxygen to diffuse
  • contains haemoglobin -> can bind to oxygen
• Haemoglobin is a protein found in red blood cells which can bind to oxygen.

  oxygen + haemoglobin ------> oxyhaemoglobin

  This is a reversible reaction and oxygen will disassociate from haemoglobin in the body tissues, where there is a low oxygen concentration

  oxyhaemoglobin -----> oxygen + haemoglobin
• White blood cells are part of the immune system and are involved in destroying pathogens

  There are two types of white blood cells:

  • phagocytes- engulf and digest pathogens
  • lymphocytes - produces antibodies that are specific to a particular pathogen and destroys them
• Atrium - pumps blood into the ventricles

  Ventricles - pumps blood out of the heart

  Vena Cava - brings deoxygenated blood from the body to the right atrium

  Pulmonary vein - carries oxygenated blood to the left atrium from the lungs

  Pulmonary artery - carries deoxygenated blood from the right ventricle to the lungs

  Aorta- carries oxygenated blood from the left ventricle to the rest of the body except from the lungs

  Valves - prevent the backflow of blood into the heart

  
• Pathway of oxygenated and deoxygenated blood

  Deoxygenated blood enters the right side of the heart through the vena cava and enters the right atrium. It is pumped into the right ventricle and is pumped out of the heart through the pulmonary artery to the lungs.

  Oxygenated blood returns from the lungs to the left side of the heart, it enters through the pulmonary vein into the left atrium. It is pumped out of the left atrium into the left ventricle and out of the left side of the heart to the rest of the body through the aorta.

  Close
• Coronary arteries provide blood to the heart muscle with oxygen, glucose and amino acids

  
• Arteries carry blood away from the heart under high pressure and have thick walls to withstand the pressure

  Veins carry blood towards the heart under low pressure, they have valves to prevent blood flowing backwards

  Capillaries links the arteries and veins and is only once cell thick and have a large surface area to allow efficient exchange of materials