(9) transport in animals

• Circulatory system


  System of blood vessels with a pump and valves to ensure one way flow of blood
• Single circulation


  • Passes heart once
  • 1 atrium 1 ventricle
  • Low blood pressure
  • No septum
• Double circulation


  • Passes heart twice
  • 2 atrium 2 ventricle
  • High blood pressure
  • Septum, separate deoxygenated and oxygenated blood
  • Allows oxygen to be delivered faster and more efficiently
• Ventricles


  Thicker muscle walls than atria because they pump blood out of heart and need higher pressure
• Left ventricle


  Muscle wall is thicker than right ventricle because it pumps to whole body, right ventricle pumps to just lungs
• Septum


  Separates oxygenated and deoxygenated blood
• Monitoring heart activity


  1. ECG

  2. Pulse rate

  3. Listening to sound of valves closing
• During exercise


  • Heart rate increases
  • Muscle cells need more energy
  • Need more oxygen and glucose for respiration
• Coronary heart disease


  • Blockage of coronary arteries (they supply blood to heart muscles)
  • Risk factors: diet, lack of exercise, stress, smoking, genetics, age, gender
  • Reduce by: not smoking, maintain healthy diet with less fat, regular exercise
• Arteries


  • Thick muscle walls, withstand high blood pressure
  • Narrow lumen, maintain high blood pressure
  • No valves, high blood pressure prevents back flow
• Veins


  • Thin muscular walls
  • Large lumen
  • Has valves
• Capillaries


  • Carry blood to and from body cells
  • Both deoxygenated and oxygenated blood
  • Low pressure
  • One cell thick, substances diffuse in and out easily
  • Very small lumen
  • No valves
• Blood vessels


  • Vena cava
  • Aorta
  • Pulmonary artery
  • Pulmonary vein
  • Renal artery
  • Renal vein
  • Hepatic artery
  • Hepatic veins
  • Hepatic portal vein
• Blood components


  • Red blood cells
  • White blood cells
  • Platelets
  • Plasma
• Red blood cells


  Transport oxygen, contain haemoglobin
• White blood cells


  • Lymphocytes produce antibody
  • Phagocytes engulf pathogens by phagocytosis
• Platelets


  Blood clotting, releases chemicals, converts fibrinogen to fibrin, forms a mesh to prevent blood loss and entry of pathogens
• Plasma


  Transports ion nutrients, urea, hormones and carbon dioxide