The pathways through which oxygen reaches the cells varies from organism to organism. In the case of unicellular beings, oxygen diffuses directly from the environment into the cell. In the case of higher organisms, including humans, a transportation system in the body distributes oxygen taken from the environment by a specialized organ (gills, lungs). Nose and nostrils. The larynx as respiratory and voice organ. Windpipe (trachea). Lung position and structure. Alveoli. Blood irrigation. Gaseous exchange. Volume of air respired. Regulation of breathing. Lung diseases. Damage of the breathing organs caused by environmental factors. Blood as mediator between the cells in the body and the environment. Using the circulatory pathways, blood transports different substances: nutrients, respiratory gases, intermediate and end products of metabolism, active substances and substances of the immune system. Blood components. Blood groups. Blood clotting. Antibodies. Rhesus intolerance. Lymphatic system. The human immune system and its functions. Anatomy of the heart, cardiac valves, heart muscles, functions and impulses. Electrocardiogram. Blood circulation. Arteries, veins and capillaries. Regulation of blood pressure, measuring blood pressure. Exchange of substances between capillaries and tissues.
Computer and processor: 500-megahertz x86 or x64 processor
Operating system: Windows 95 and above
RAM: 16 MB RAM
Display: 1024 x 768 pixels
Can also run on PowerMac G4 and above with the help of emulation software.