Vein - A blood vessel that carries BLOOD to the HEART. All veins except the PULMONARY VEINS carry deoxygenated blood; the pulmonary veins return oxygenated blood to the heart from the LUNGS. Because veins lack the muscular structure and contractile capability of arteries, they have valves that keep blood moving only in one direction, toward the heart. The body’s largest veins are the superior VENA CAVA and the inferior vena cava, which empty blood into the heart’s right atrium.
For further discussion of the veins within the context of cardiovascular structure and function please see the overview section “The Cardiovascular System.”
See also ARTERY.
Resource: Facts On File Encyclopedia Of Health And Medicine
Aerobic Fitness and Cardiovascular System The efficiency with which the cardiovascular system functions to meet the oxygen needs of cells throughout the body, particularly under the increased pressure of intense physical activity or exercise. The higher a person’s aerobic FITNESS LEVEL, the more air the LUNGS can take in each breath, the more oxygen
The most significant age-related changes in cardiovascular function occur at birth in both sexes and with MENOPAUSE in women. Though changes in METABOLISM occur with aging that affect all body systems, researchers now believe cardiovascular health does not inherently decline simply as a function of aging. DIABETES, OBESITY, lack of physical exercise, and
What is Aneurysm and Definition Aneurysm is a weakened and often distended (stretched) area in the wall of an ARTERY. Though an aneurysm may develop in any artery, the most common location is the descending or abdominal AORTA. An aneurysm is potentially life-threatening. The continual pressure of the BLOOD flowing through the artery pressures the weakened
What is Wolff-Parkinson-White syndrome Wolff-Parkinson-White syndrome - An inherited ARRHYTHMIA disorder in which an extra conduction pathway, called an accessory pathway, exists between the heart’s atria and ventricles. The accessory pathway allows the heart’s electrical pacing impulse to bypass the normal conductive route, reaching the
What is Ventricular Fibrillation Ventricular fibrillation - Rapid, irregular, ineffective contractions of the heart’s ventricles. Ventricular fibrillation quickly becomes fatal without treatment. The HEART cannot pump blood to the LUNGS or to the body when it is in ventricular fibrillation. Ventricular fibrillation is a life-threatening event that
What is Ventricular assist devices (VADs) Ventricular Assist Devices - Implanted mechanical pumps that aid the native HEART, taking over some of the workload of the ventricles. Several types of VADs are available, each with somewhat different features and functions. A VAD may assist the right or left ventricle, and in some cases both ventricles, as a
What is Venogram - diagnostic procedure Venogram is a diagnostic procedure to evaluate the flow of blood in the veins, usually in the legs. The cardiologist may use venogram to diagnose VARICOSE VEINS, VENOUS INSUFFICIENCY, or DEEP VEIN THROMBOSIS (DVT). For venogram, the radiologist injects a small amount of contrast dye into the affected VEIN network and
What is chronic Venous Insufficiency and Symptoms Venous insufficiency is a chronic condition in which the veins cannot adequately return BLOOD to the HEART, usually as a consequence of defective valves that allow blood to leak back and pool in the veins. Some people do not have valves in their veins, a circumstance that is a CONGENITAL ANOMALY. Venous
Vena Cava are the two largest veins in human body together called the venae. These veins collectively return deoxygenated BLOOD to the HEART. Both of them deplete all the blood into the right atrium. The superior vena cava, large but short vein, brings blood from the upper part of the organism, the head and upper limbs, and empties into the top of the right
What is Vein and Definition Vein - A blood vessel that carries BLOOD to the HEART. All veins except the PULMONARY VEINS carry deoxygenated blood; the pulmonary veins return oxygenated blood to the heart from the LUNGS. Because veins lack the muscular structure and contractile capability of arteries, they have valves that keep blood moving only in one