Human Structure Virtual Histology
    Urinary System

    The urinary system consists of the kidneys, ureters, bladder, and urethra and is responsible for the important bodily functions of soluble waste production, storage, and elimination. Urine containing waste substances is produced in the kidney as a blood filtrate. It is transported via the ureters to the bladder where it is stored and eventually eliminated through the urethra. This process also results in the salvaging of water, sugars, proteins, and ions from the blood filtrate, which are returned to the blood. The kidneys also have a variety of other important functions. They play a role in controlling systemic blood pressure by the secretion of renin, erythrocyte production by secretion of erythropoietin, excretion of drugs and other bioactive substances, and activation of vitamin D.

    The learning objectives for this unit are:

    • Identify the histologic and cellular characteristics of the functional components of the nephron and verify their relationships with either the kidney cortex or medulla.
    • Identify the structural and cellular characteristics of the ureter, urinary bladder, and urethra.

    Let's start with the basic structure of the kidney.