Hovedkredsløbet

Hovedkredsløbet, also known as the systemic circulation, is the part of the circulatory system that carries oxygenated blood from the left ventricle of the heart to the rest of the body and returns deoxygenated blood from the body to the right atrium of the heart. This circulation system is distinct from the pulmonary circulation, which transports blood between the heart and the lungs.

The systemic circulation begins when the left ventricle pumps oxygenated blood into the aorta, the largest artery in the body. From the aorta, blood branches out into progressively smaller arteries, which then lead to arterioles and finally to capillaries. Capillaries are tiny blood vessels where the exchange of oxygen and nutrients for carbon dioxide and waste products occurs with the body's tissues.

After passing through the capillaries, the deoxygenated blood enters venules, which merge into larger veins. These veins eventually converge to form the superior vena cava and the inferior vena cava, the two largest veins in the body. These vena cavae return the deoxygenated blood to the right atrium of the heart, completing the circuit of the systemic circulation. The continuous flow of blood through the hovedkredsløbet is essential for supplying all organs and tissues with the necessary oxygen and nutrients for their function and for removing waste products.