[Functional morphology of the kidney. A review of the histophysiology of the kidney glomerulus, the nephrons and the collecting tubule system].

The kidney is a composite organ, the specific activities of which are attributable to the peculiar construction of the individual components of the glomerula, nephrons and collecting tubules. This comprehensive review will address the essential physiological mechanisms of urine formation, such as filtration, secretion, reabsorption and concentration, and correlate these functions to morphological structures where possible. The complex structure of the renal glomerulus as the basis for the formation of primary urine (blood-urine barrier) will be documented on the basis of electron micrographs. In addition to this, the ultrastructure of the epithelium in the various tubular segments and collecting tubules will be discussed from a histophysiological stand-point, including its significance in the excretion of waste substances and maintenance of a constant fluid environment in the body (Homeostasis).