FUNCTIONS OF THE BLOOD

Blood circulation in human beings is double and complete. It is double because it has two circuits (general and pulmonary) and complete because the blood in the veins never mixes with the blood in the arteries. There are three kinds of blood vessels: arteries which go from the heart to the tissues, capillaries, minute vessels which are responsible for transporting the blood in the tissues, and veins that return the blood to the heart.

FUNCIONS:
1.Transports oxygen from the lungs to body tissues and transports the waste products of cellular metabolism and nutrients, hormones and enzymes.
2.Regulates blood clotting, body temperature, acid-base balance, water and electrolytes.
3.Protects against harmful organisms through white cells and antibodies.

RESPIRATORY SYSTEM

-- THE RESPIRATORI SYSTEM--

A respiratory system's function is to let gas exchange. The space between the alveoli and the capillaries, the anatomy or structure of the exchange system, and the precise physiological uses of the exchanged gases vary depending on the organism. In humans and other mammals, for example, the anatomical features of the respiratory system include airways, lungs, and the respiratory muscles. Molecules of oxygen and carbon dioxide are passively exchanged, by diffusion, between the gaseous external environment and the blood.