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
Basilar artery Basilar artery In human anatomy, the basilar artery is one of the arteries that supplies the brain with oxygen-rich blood. The two vertebral arteries and the basilar artery are sometimes together called the "vertebrobasilar system", which supplies blood to the posterior part of the circle of Willis and joins with blood supplied to the anterior part of the circle of Willis from the internal carotid arteries. The basilar artery arises from the confluence of the two vertebral arteries at the junction between the medulla oblongata and the pons between the VIth cranial nerves. It ascends superiorly in the basilar sulcus