Blood circulation

Synonym: Circulation
German: Blutkreislauf

1 Definition

The blood circulation is the physiological transport process of arterial and/or venous blood through the vascular system and the heart chambers. It is driven by the heart's pump function.

2 Classification

One distinguishes between the systemic and the pulmonary circulation.

2.1 Systemic circulation (body circulation)

The systemic circulation starts from the left ventricle of the heart. From there the oxygenated blood is pumped into the aorta, which feeds into the downstream arteries and/or arterioles and eventually into the capillaries of the body. The blood then flows from the capillary bed into the venules and veins and from there reaches the right atrium of the heart through the superior and inferior venae cavae.

2.2 Pulmonary circulation (lung circulation)

The pulmonary circulation starts from the right ventricle of the heart. From there the de-oxygenated blood is pumped through the pulmonary arteries into the capillaries of the pumonary alveoli. From these capillary beds the blood flows into the left atrium of the heart via the pulmonary veins and can then start its journey once again into the systemic circulation.

3 Functions

The most important functions of the circulation are:

• Oxygen supply
• Nutrient supply of the body's cells
• Removal of metabolic end-products
• Transport and/or distribution of heat