Biology: Circulatory system

• What are the two main functions of the circulatory system?

  Transport and protection
• What does the circulatory system transport?

  Blood cells, food molecules, carbon dioxide, urea
• What does the circulatory system protect against?

  Disease
• What is the liquid component of blood called?

  Plasma
• What type of blood cell is responsible for oxygen transport?

  Red blood cell
• Which type of cell in the blood is known as a phagocyte?

  White blood cell
• Which type of cell in the blood is known as a lymphocyte?

  White blood cell
• What shape do red blood cells have?

  Disc
• Why does the disc shape of red blood cells provide a large surface area?

  For efficient gas exchange
• What is the function of haemoglobin in red blood cells?

  To carry oxygen
• What process do phagocytes use to ingest microorganisms?

  Phagocytosis
• What do lymphocytes produce?

  Antibodies
• What are platelets important for?

  Blood clotting
• What protein do platelets convert to form a mesh?

  Fibrinogen
• What does fibrin form?

  A mesh network
• What does the fibrin mesh trap to form a clot?

  Red blood cells
• What can a mesh and red blood cells form?

  A scab
• What is the function of plasma?

  Transport of blood components
• What does plasma transport?

  Blood cells, food molecules, carbon dioxide, hormones, urea
• Why is it important that plasma concentration is similar to blood cell concentration?

  To prevent cell lysis
• What happens to red blood cells in water?

  They take in water and burst
• What is the name of the process where cells burst due to water intake?

  Cell lysis
• What happens to cells placed in a concentrated salt solution?

  Cells shrink and shrivel
• Which type of blood vessel has thick walls of muscle and elastic fibres?

  Artery
• Which type of blood vessel has a small lumen?

  Artery
• Which type of blood vessel has relatively thin walls and few elastic fibres?

  Vein
• Which type of blood vessel has a relatively large lumen?

  Vein
• Which type of blood vessel is very fine and has very thin walls?

  Capillary
• What type of blood do arteries normally carry?

  Oxygenated
• Why do arteries have relatively thick walls?

  To withstand high pressure
• Why do the thick walls of arteries have muscles and elastic fibres?

  To expand and recoil
• What is the purpose of the elastic fibres recoiling in arteries?

  Maintaining blood pressure
• Why do veins have relatively thin walls?

  They carry blood at low pressure
• Why are valves necessary in veins?

  To prevent backflow
• What type of blood do veins normally carry?

  Deoxygenated
• How does the large lumen of veins aid blood movement?

  Reduces friction
• Where does diffusion of oxygen, carbon dioxide, and dissolved food take place?

  Between capillaries and body cells
• Why are the walls of capillaries thin?

  To allow diffusion
• What type of blood is normally transported through arteries?

  Oxygenated
• What type of blood is normally transported through veins?

  Deoxygenated