Circulatory system 1

• What does blood contain?


  Plasma, red blood cells, white blood cells and platelets
• Blood is a fluid(fluid is ) but why is it a tissue aswell?

  Collection of specialised cells
• Plasma

  • Transports useful substances around body
  • Transports waste products(urea)
  • Carries the other parts of bloood
• What does red blood cell(erythoctuyes ) do?

  Transport oxygen to all cells
• Red blood cell

  • Has no nucleus so more space for haemoglobin
  • Concave shape for large surface area for absorbing oxygen
  • Small to pass through narrow capillaries
  • Absorb co2 and carry from cells to lungs(exhale)
• What is haemoglobin?


  Molecules that hold oxygen
• White blood cells fight infection as part of body immune system don't have
• 2 types of white blood cell

  Phagoctyyes and lymphocytes
• • Phacoytes kill pathogens by engulfing and digesting them by changing shape to surround pathogen
• • Lymphocytes destroy pathogens and toxins by releasing antibodies and antitoxins
• How do platelets stop bleeding

  Platelets in blood stick together and form clot over wound
• How do platelets stick toghether

  Covered in proteins
• Three types of blood vessels in circulatory system?

  Arteries, veins, capillaries
• What do arteries carry blood away from?

  Heart
• What do arteries have?

  Thick elastic walls to cope with high pressure of blood
• What do veins carry blood back too

  Heart
• Veins

  • Veins wide to help blood flow Contain valves so blood flow In right direction
• What are capillaries?

  Tiny vessels that carry blood to every cell in body
• What do capillaries have and why?

  Thin wall to allow substances like oxygen and nutrients to move in and out of blood