Kidney Kidney The kidneys are two bean-shaped organs found in vertebrates. They are located on the left and right in the retroperitoneal space, and in adult humans are about in length. They receive blood from the paired renal arteries; blood exits into the paired renal veins. Each kidney is attached to a ureter, a tube that carries excreted urine to the bladder. The nephron is the structural and functional unit of the kidney. Each adult kidney contains around 1 million nephrons. The nephron utilizes four processes to alter the blood plasma which flows to it: filtration, reabsorption, secretion, and excretion. The
Left anterior descending artery the right aortic sinus. In 78% of cases, it reaches the apex of the heart. The LAD gives off two types of branches: "septals" and "diagonals". The artery supplies the anterolateral myocardium, apex, and interventricular septum. The LAD typically supplies 45-55% of the left ventricle (LV) and is therefore considered the most critical vessel in terms of myocardial blood supply. The "widow maker" is an alternate name for the anterior interventricular branch of the left coronary artery. The name "widow maker" may also apply to the left coronary artery or severe occlusions to that artery. This term is used because