A full blood supply to all organs and organism tissues depends on the cardiovascular system. Digestive system performs digestion of eaten foods and provides an entire organism with required nutrition. Immune system creates protection of an organism protection against morbific bacteria and viruses. Respiratory system supplies the basis of life - oxygen to an organism. State of all cells in the organism depends on its functioning quality.
Neural system is the intellect, memory and activity of a human being.
Power of the neural system protects us against stresses. Urinary system regulates amount of liquid in an organism and removes harmful substances out of it. State of joints determines the freedom of motions. Good state of this system provides us with a feeling of juvenility, resilience and body mobility. Adaptation load is practically not sensible.