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
Intersegmental artery with the exception of the 5th (last) lumbar intersegmental artery, which becomes the common iliac arteries. These arteries merge into the lateral sacral artery. Intersegmental artery The intersegmental arteries are a set of 30 arteries arising from the embryonic dorsal aorta, with each artery providing blood supply to one somite and its derivatives. The cervical intersegmental arteries merge into the vertebral artery with the exception of the 7th (or possibly the 6th) cervical intersegmental artery, which becomes the subclavian artery. The confusion arises because the vertebral artery drains into the subclavian artery following the disappearance of the dorsal aortae in