Gcse Biology Aqa Heart+Blood Vessles

• Aorta is probably the biggest artery in the body, leaving the heart to go to the body
• Major blood vessels related to the heart

  • Pulmonary artery
  • Pulmonary vein
  • Aorta
  • Vena cava
• Labelling the heart

  1. Right side is labeled as the left and left side is labeled as the right

  2. Key words: atrium and ventricle

  3. If more than one atrium, it's atria

  4. Four chambers: left atrium, left ventricle, right atrium, right ventricle
• Valves are important structures between the atria and ventricles and at the beginning of the main blood vessels leaving the heart to ensure blood travels in the right direction
• Vena cava is the main vein that returns from the body to the heart
• Humans and mammals have a double circulation with two loops in the circulation of blood around the body
• Coronary arteries give blood to the heart for oxygen, glucose, and nutrients
• Anytime you see the word 'pulmonary', it's often related to the lungs
• The heart is important because it pumps blood around the body, delivering nutrients to all cells and carrying away waste
• Pulmonary artery goes to the lungs


  Pulmonary vein comes back from the lungs
• Structure of blood vessels

  Arteries have thick muscular walls to withstand pressure and help in blood movement. Arterioles branch off from arteries, then capillaries, venules, and finally veins
• Transport of nutrients and waste in the body

  Nutrients like glucose, oxygen, amino acids are carried for various functions including respiration. Waste materials like urea, carbon dioxide, lactic acid are carried away
• Double circulation in the body

  Two loops: 1) Heart to lungs and back to heart, 2) Heart to body (including head) and back to heart
• Arterioles and venules are not mentioned in the spec but good to know
• Elastic tissue in arteries helps to absorb and maintain pressure
• Details of double circulation

  First loop: Right ventricle to lungs and back to left atrium, Second loop: Left ventricle to body and back to heart. Blood visits the heart twice in one full journey around the body
• Arteries have thick muscular walls and elastic tissue, with a narrow lumen
• Elastic tissue in arteries

  Can recoil or spring back to absorb pressure and maintain high pressure to keep blood moving
• Veins

  • Thin walls
  • Thin layer of muscle
  • Thin layer of elastic tissue
  • Large lumen
  • Contain valves for one-way blood flow
  • Easily squeezed and flattened by muscle contractions
• Thin walls in capillaries


  Reduce diffusion distance for oxygen exchange between blood and cells
• Red blood cells in capillaries

  Travel down in a single-file, pressed against walls for further shortening of diffusion distance
• Capillaries are numerous throughout the body to maximize substance exchange
• Capillaries are very tiny with very thin walls, allowing for efficient exchange of substances
• Arteries

  • Thick muscular walls
  • Thick layer of elastic tissue
  • Narrow lumen
• Valves in veins

  Allow one-way blood flow, preventing backward flow
• Capillaries


  • Very tiny
  • Very thin walls (one cell thick)
  • Red blood cells travel down them in a single-file
  • Numerous throughout the body for maximized exchange of substances
• Veins have thin walls, contain valves for one-way blood flow, and are easily squeezed and flattened by muscle contractions
• What is the bottom Chamber of the heart called?

  Ventricle
• What is the top chamber of the heart called?

  Atrium
• Where does the pulmonary Artery lead?

  into the lungs
• What is one atrium called?

  atria
• What are 2 major blood vessels in the heart?

  Pulmonary Artery and Pulmonary Vein
• Oxygenated blood enters the Heart through?

  Pulmonary veins
• Oxygenated blood travels through the pulmonary vein to the?

  Left atrium
• what is the biggest artery in the body?

  aorta
• Blood leaves the heart to the rest of the body through the?

  aorta
• Deoxygenated blood enters the heart from the rest of the body through the?

  Vena cava
• Is the vena Cava a vein or an artery?


  a vein
• What is between the atria and the ventricles?

  valves
• What is the function of the valves?

  To ensure the blood flows in one direction and in the right direction