1. Unifying Concepts of Animal Circulation
   1. Diffusion
   2. Circulatory system
      1. Open circulatory systems
      2. Closed circulatory systems
      3. Central pump Vascular system Circulating fluid
2. The Human Cardiovascular System
   1. The path of blood
      1. Systemic circuit
      2. Pulmonary circuit
   2. The Cardiac Cycle
      1. Diastole
      2. Systole
      3. The pacemaker and the control of heart rate
         1. Pacemaker
         2. Sinoatrial node
   3. Blood Vessels
      1. Arteries
      2. Veins
      3. Capillaries
      4. Blood pressure
      5. Pulse
      6. Blood
         1. Erythrocytes
            1. Oxygen transport
         2. Leukocytes
            1. Defense
         3. Platelets
            1. Blood clotting
         4. Plasma
   4. Stem cells and the treatment of leukemia
      1. Bone marrow
      2. Stem cells
   5. Cardiovascular disease
3. Unifying Concepts of Animal Respiration
   1. The structure and function of respiratory surfaces
      1. Lungs
      2. Respiratory surface
      3. Wet skin
      4. Tracheal system
   2. Oxygen
   3. Glucose
   4. Carbon dioxide
4. The Human Respiratory System
   1. Breathing
      1. Ventilation
      2. Transport of gases by the circulatory system
      3. Servicing of cells within the body tissues
   2. The structure and function of respiratory surfaces
      1. Pharynx
      2. Larynx
      3. Trachea
      4. Bronchi
      5. Bronchioles
      6. Alveoli
   3. The role of hemoglobin in gas transport
      1. Hemoglobin
      2. Iron atom