ciev

Ciev is a term used in several Slavic and related languages to refer to the network of vessels that transport fluids within an organism, most commonly blood vessels. In medical usage, ciev describes arteries, veins, and capillaries that form the circulatory or vascular system.

Anatomy: The ciev system consists of arteries that carry blood away from the heart, veins that return blood, and capillaries that exchange substances with tissues. The walls of arteries and veins differ: arteries have thicker, more elastic walls to withstand higher pressures; veins have thinner walls and valves to prevent backflow. Capillaries are narrow vessels where exchange occurs. The system is organized into systemic and pulmonary circuits in humans and many vertebrates.

Physiology: Blood flow is driven by the heart and regulated by neural and hormonal signals. Oxygen and nutrients pass from capillaries to tissues, while carbon dioxide and waste move in the opposite direction. The microcirculation, including arterioles, venules, and capillaries, is critical for tissue perfusion, temperature regulation, and maintenance of blood pressure.

Health and disease: Disorders affecting ciev include hypertension, atherosclerosis, aneurysms, venous insufficiency, and thrombosis. Diagnostic methods include ultrasound, Doppler imaging, angiography, and laboratory tests. Treatments range from lifestyle changes and medications to surgical interventions in some cases.

In language and scholarship, ciev may be used with regional spellings or translations; in English-language texts the term is commonly expressed as vascular system or circulatory system. See also circulatory system, vascular biology.