Circulatory System 3 - Blood

• 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  ? which bind to oxygen. 

  haemoglobin
• How are red blood cells adapted for their function?

  They have no nucleus to fit in more haemoglobin 

  They have a biconcave shape to increase their surface area
• What is the role of white blood cells?

  To defend against pathogens 
• What is the process by which a white blood cell binds to, and then engulfs a pathogen, in order to destroy it ?

  Phagocytosis
• 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 breaks 
• Give two reasons why it is so important that our blood clots when we are cut.

  Blood clotting is important because it prevents us from losing blood from the blood vessels, and it also prevents pathogens from entering the blood, which could cause infection. 
• Do platelets have a nucleus? 

  no
• 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.

  Name as many of these smaller dissolved substances as you can?

  Glucose

  Amino acids

  Fatty acids

  Glycerol

  Carbon dioxide 

  Urea 

  Antibodies 

  Hormones