Microcirculation is an offshoot of the circulatory system and deals with the flow of blood within the small vessels. This is in contrast to macrocirculation, which deals with the flow of blood in the larger vessels like the veins and arteries. The vessels connected to microcirculation are the capillaries, as microcirculation is a vital link between the capillaries, tissues and cells. The flow of blood means that the single cell and tissue receive nourishment and oxygen leading to the overall health of organs and tissues like the skin.
The microcirculatory network lies between the venules and the arterioles. The venules are small veins that receive the blood from the capillaries after they have distributed them to the organs and tissues. Blood progresses from the venules into the larger veins, which carry them to the heart. As the blood flows to the heart, it collects waste matter like carbon dioxide that needs to be excreted from the body. From the heart, the blood is carried away by the arteries under high pressure related to the pumping of the heart.
This blood eventually finds its way into tiny arteries known as arterioles, which deposit the blood into capillaries for supply to the tissues and organs, completing the microcirculatory circle. Microcirculation also allows for the exchange or transfer of other substances between the blood and tissue. For instance, it serves as a vehicle which conveys drugs, electrolytes and glucose.
Other objects transferred to the tissues through microcirculation include water molecules, which are able to cross from the capillary to the tissues since they are smaller than the pores in the capillary walls. This process is known as water conductivity. Electrolytes cross through the walls of the capillaries as well. The transfer of oxygen from the capillaries to the tissues also occurs through the walls of the capillaries, which use the same process to gather the carbon dioxide that it carries away from the tissues and organs in various parts of the body.
Blood vessels come in different shapes and sizes ranging from the arteries and veins to the capillaries. The capillaries are a fine network of small blood vessels deep within the the body, which distribute blood to tissues and organs. The small size of the capillaries makes it easy for them to be located in practically every part of the body, including areas with very thin skin such as the eyelids. This allows them to supply the tissues and single cells with nutrients and oxygen carried in the blood.