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
Posterior interventricular artery Posterior interventricular artery In the coronary circulation, the posterior interventricular artery (PIV, PIA, or PIVA), most often called the posterior descending artery (PDA), is an artery running in the posterior interventricular sulcus to the apex of the heart where it meets with the anterior interventricular artery or also known as Left Anterior Descending artery. It supplies the posterior third of the interventricular septum. The remaining anterior two-thirds is supplied by the anterior interventricular artery which is a septal branch of the left anterior descending artery, which is a branch of left coronary artery. It is typically a branch of the