Circulation pack 3 part 1

• What is one of the main jobs of the circulatory system?

  To act as a huge transport system.
• What are the four main components of blood?

  • Red blood cells
  • White blood cells
  • Platelets
  • Plasma
• What is the primary function of red blood cells?

  To carry oxygen from the lungs to all the cells in the body.
• How do red blood cells appear in shape?

  They look like doughnuts that are pressed in at the top.
• Why do red blood cells not have a nucleus?

  To allow more room to carry oxygen.
• What pigment do red blood cells contain?

  A red pigment called hemoglobin.
• What happens to hemoglobin in body tissues?


  It splits into hemoglobin and oxygen.
• What is the role of white blood cells?

  To defend against infection.
• What are phagocytes?


  White blood cells that can change shape to engulf unwelcome microorganisms.
• What is the process called when phagocytes engulf microorganisms?

  Phagocytosis.
• What do lymphocytes produce?


  Antibodies against microorganisms.
• What happens to white blood cells during an infection?

  They multiply to fight it off.
• What are platelets?


  Small fragments of cells that help blood clot.
• Why are platelets important?

  They help stop bleeding and prevent microorganisms from entering wounds.
• What can a lack of platelets cause?

  Excessive bleeding and bruising.
• What is plasma and what does it carry?

  • A pale straw-colored liquid
  • Carries:
  • Red and white blood cells and platelets
  • Nutrients (like glucose and amino acids)
  • Carbon dioxide
  • Urea
  • Hormones
  • Proteins
  • Antibodies and antitoxins
• Why do doctors often take blood samples for analysis?

  Because blood transports many chemicals produced by various organs.
• What can blood tests diagnose?

  Many disorders, not just those of the blood.
• What is the role of platelets in blood?

  To help blood clot at a wound.