2.12 - Circulatory System (Blood)

• What is blood made up of?

  Red blood cells

  White blood cells

  Platelets

  Plasma
• What is the role of red blood cells?

  To carry oxygen from the lungs to the tissues
• What protein do red blood cells contain that bind to oxygen?

  Haemoglobin
• What shape do red blood cells have to increase their surface area?

  Biconcave shape
• Why do red blood cells have no nucleus?

  To fit in more haemoglobin
• What is the function of haemoglobin in red blood cells?

  To carry oxygen
• Do red blood cells have a nucleus?

  No, they have no nucleus
• How does the biconcave shape of red blood cells benefit their function?

  It increases surface area for oxygen absorption
• What are the adaptations of red blood cells for their function?

  • Biconcave shape increases surface area
  • No nucleus allows more haemoglobin
  • Flexible to navigate through capillaries
• What is the role of white blood cells?

  To defend against pathogens
• What is phagocytosis?

  Process of engulfing pathogens by white blood cells
• Why do white blood cells perform phagocytosis?

  To bind and destroy pathogens
• What happens to a pathogen during phagocytosis?

  It is engulfed and destroyed by the cell
• How does phagocytosis contribute to the immune response?

  It eliminates pathogens to protect the body
• How do antibodies help defend against pathogens?

  They bind to pathogens and help immune cells destroy them
• Do white blood cells have a nucleus?


  Yes
• What is the role of platelets?

  To clot the blood when a blood vessel is broken
• Give two reasons why it is so important that our blood clots when we are cut.

  Prevents blood from leaving blood vessels

  Prevents pathogens entering the blood
• What are platelets?


  Fragments of cells, they do not have a nucleus like normal cells
• What is the role of blood plasma?

  To carry substances and cells around the body
• The blood plasma is a yellowish liquid that makes up 55% of the bloods volume. Its role is to carry large structures like red blood cells, white blood cells, and platelets, as well as smaller dissolved substances. What are the names of these smaller dissolved substances?

  Nutrients: glucose, amino acids, fatty acids and glycerol

  Waste products: CO2 and urea

  Other substances: hormones and antibodies