Verenkierto

Verenkierto, a Finnish term meaning blood circulation, refers to the circulatory system that moves blood through the body. In humans and other vertebrates it is a closed system consisting of the heart, a network of blood vessels, and the blood. The system supplies oxygen and nutrients, removes wastes, and helps regulate temperature and pH.

The heart has four chambers: right atrium, right ventricle, left atrium, and left ventricle. Blood moves through the heart via four valves: tricuspid, pulmonary, mitral, and aortic, ensuring one-way flow. The right heart handles deoxygenated blood from the body and sends it to the lungs; the left heart receives oxygenated blood from the lungs and pumps it to the body.

Circulation is divided into pulmonary circulation (heart to lungs and back) and systemic circulation (heart to body and back). Arteries carry blood away from the heart, while capillaries exchange substances with tissues, and veins return blood to the heart. The main arterial trunk is the aorta; the main venous channels are the superior and inferior venae cavae.

Electrical impulses regulate the heartbeat, with the sinoatrial node acting as the primary pacemaker. Autonomic nerves and hormones modulate rate and force. Blood consists of plasma, red and white blood cells, and platelets, supporting oxygen transport, immunity, and clotting. Blood pressure, measured as systolic over diastolic pressure, reflects circulatory status.

Dysfunctions of verenkierto can cause cardiovascular diseases such as hypertension, coronary artery disease, heart failure, and stroke. Prevention emphasizes healthy lifestyle, risk factor management, and appropriate medical treatment. The term verenkierto is a foundational concept in physiology and medicine.