B2- blood and heart

• The _______ ventricle has thicker walls because it has to pump blood all the way around the body.

  left
• Which blood vessel carries deoxygenated blood from the heart to the lungs?

  Pulmonary artery
• The journey of blood around the body

  Body tissues ➔ vena cava ➔ right atrium ➔ right ventricle ➔ pulmonary artery ➔ lungs ➔ pulmonary vein ➔ left atrium ➔ left ventricle ➔ aorta ➔ body tissues
• Which blood vessel carries oxygenated blood from the heart to the body?

  Aorta
• The movement of blood between the ventricles and atria: 

  1. The walls of the atria contract, pushing blood into the relaxed ventricles.
  2. The walls of the ventricles contract, pushing blood out of the heart. At the same time, more blood will enter the now-relaxed atria.
  3. The cycle repeats.
• Pacemaker cells are found in which chamber of the heart?

  Right atrium
• What do arteries do?

  They carry blood away from the heart
• What do veins do?

  Carry blood towards the heart.
• What do capillaries do?

  Capillaries carry blood through the body tissues, allowing oxygen, nutrients, and waste products, to be exchanged between tissues and the blood.
• Structure and function of arteries 

  1. Artery walls have a thick middle layer, containing both muscle and elastic tissue.
  2. Compared to their walls, arteries have a relatively narrow lumen, which keeps the blood pressure high.
  3. The muscle tissue provides strength, and allows the arteries to direct blood flow.
• Structure and function of capillaries 

  1. The role of capillaries is to exchange nutrients and waste products with the tissues.
  2. Capillaries carry blood at a low pressure and have a lower rate of flow than arteries.
  3. Their walls are also only one cell thick and permeable which means a short distance for diffusion and substances can move through them
• Structure and function of veins 

  1. The role of veins is to carry blood from the body (or lungs) back to the heart.
  2. Veins are a similar size to arteries, but they have relatively thin walls and a relatively wide lumen
  3. This is because they carry blood at a much lower pressure.
  4. Veins also contain valves to prevent the blood from flowing backwards.
• What is the role of red blood cells?

  to carry oxygen from the lungs to the tissues 
• Red blood cells are 

  packed full of a large proteins called haemoglobin, which bind to oxygen. 
• How are red blood cells adapted for their function?

  They have a biconcave shape to increase their surface area

  They have no nucleus to fit in more haemoglobin 
• What is the role of white blood cells?

  To defend against pathogens 
• What is the role of platelets
• How do antibodies help defend against pathogens? 

  They bind to pathogens and help immune cells destroy themv
• Give two reasons why it is so important that our blood clots when we are cut.

  Prevents blood from leaving the blood vessels 

  Prevents pathogens from entering the blood 
• What is the role of blood plasma?


  To carry substances and cells around the body