cardiovasular

Cardiovascular refers to the heart and the network of blood vessels that circulate blood through the body. The cardiovascular system supplies oxygen and nutrients to tissues, removes carbon dioxide and other wastes, and helps regulate temperature and pH. Blood travels through two major circuits: the pulmonary circulation, which exchanges gases in the lungs, and the systemic circulation, which supplies the rest of the body.

The heart is a muscular organ that functions as a four-chamber pump. Blood moves from the right atrium to the right ventricle, through the pulmonary artery to the lungs, back via the pulmonary veins into the left atrium, then into the left ventricle and out through the aorta to the body. Valves ensure unidirectional flow. The heart's rhythmic contractions are coordinated by the electrical conduction system, including the sinoatrial node, atrioventricular node, and Purkinje fibers.

Arteries carry blood away from the heart, with thick muscular walls; veins return blood to the heart, aided by valves and surrounding muscles; capillaries connect arteries and veins and enable exchange of gases, nutrients, and wastes. Major vessels include the aorta, pulmonary vessels, superior and inferior vena cavae, and coronary arteries supplying the heart muscle itself.

Cardiovascular dynamics are described by cardiac output, the product of heart rate and stroke volume, and by systemic blood pressure. These are regulated by autonomic nervous activity, hormones, and reflexes, and are assessed by tests such as blood pressure measurement and imaging or electrocardiography.

Common conditions involve atherosclerosis, coronary artery disease, heart failure, arrhythmias, and hypertension. Risk factors include age, smoking, high cholesterol, diabetes, obesity, and physical inactivity. Prevention focuses on healthy diet, regular exercise, maintaining blood pressure and lipid levels, and avoiding tobacco. Note: the standard term is cardiovascular.