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
Bladder cancer is by way of cystoscopy, which is a procedure in which a flexible tube bearing a camera and various instruments is introduced into the bladder through the urethra. The procedure allows for a visual inspection of the bladder, for minor remedial work to be undertaken and for samples of suspicious lesions to be taken for a biopsy. Urine cytology can be obtained in voided urine or at the time of the cystoscopy ("bladder washing"). Cytology is not very sensitive (a negative result cannot reliably exclude bladder cancer). There are newer non-invasive urine bound markers available as aids in the diagnosis