1.2 blood vessels

• artery: a thick-walled blood vessel that carries blood away from the heart
• vein: a thin-walled blood vessel with valves that carries blood toward the heart
• capillary: a tiny blood vessel that connects the smallest branch of an artery to the smallest branch of a vein
• vena cavae: the largest veins in the body that carry oxygen-poor blood to the heart
• pulmonary artery: the large blood vessel that carries oxygen-poor blood from the heart's right ventricle to the lungs
• pulmonary vein: the large blood vessel that carries oxygenated (oxygen-rich) blood from the lunch to the heart's left atrium
• aorta: the largest artery in the body; carries oxygen-rich blood from the left ventricle of the heart
• arteriole: a small artery that joins a larger artery to a capillary
• capillary bed: a network of capillaries in a particular area or organ of the body
• venule: a small vein that joins a larger vein to capillary
• varicose vein: an enlarged, twisted vein near the surface of the skin resulting from poorly functioning valves
• blood pressure: the pressure exerted by blood against the walls of blood vessels such as arteries
• millimetres of mercury: a unit for measuring pressure in terms of the height of a column of mercury that can be supported by that pressure
• mmHg: the symbol for millimetres of mercury
• systolic pressure: the pressure exerted on the artery walls when the heart's ventricles are contracting
• diastolic pressure: the residual pressure exerted on the artery walls when the heart's ventricles are relaxing
• hypertension: chronic, abnormally high blood pressure, characterized by values greater than 140/90