catheter /kath″ətər/ [Gk, katheter, something lowered] , a hollow flexible tube that can be inserted into a vessel or cavity of the body to withdraw or instill fluids, directly monitor various types of information, and visualize a vessel or cavity. Most catheters are made of soft plastic, rubber, or silicon. Kinds include acorn-tipped catheter, angiocatheter, Foley catheter, intrauterine catheter.
A, Right-sided heart catheterization. The catheter is inserted into the femoral vein and advanced through the inferior vena cava (or, if into an antecubital or basilic vein, through the superior vena cava), right atrium, and right ventricle and into the pulmonary artery. B, Left-sided heart catheterization. The catheter is inserted into the femoral artery or the antecubital artery. The catheter is passed through the ascending aorta, through the aortic valve, and into the left ventricle. (Mosby, 2003)
