Blood vessel Blood vessel The blood vessels are the part of the circulatory system, and microcirculation, that transports blood throughout the human body. These vessels are designed to transport nutrients and oxygen to the tissues of the body. They also take waste and carbon dioxide and carry them away from the tissues and back to the heart. Blood vessels are needed to sustain life as all of the body’s tissues rely on their functionality.There are three major types of blood vessels: the arteries, which carry the blood away from the heart; the capillaries, which enable the actual exchange of water and chemicals
Blood other blood liquids and not connected to hemoglobin. The hemoglobin molecule is the primary transporter of oxygen in mammals and many other species (for exceptions, see below). Hemoglobin has an oxygen binding capacity between 1.36 and 1.40 ml O per gram hemoglobin, which increases the total blood oxygen capacity seventyfold, compared to if oxygen solely were carried by its solubility of 0.03 ml O per liter blood per mm Hg partial pressure of oxygen (about 100 mm Hg in arteries). With the exception of pulmonary and umbilical arteries and their corresponding veins, arteries carry oxygenated blood away from the heart