Episode of Series “Biology program. Unit 4. Physiology”.
The film opens with an analogy between the kidneys and the selective processes by which they eliminate waste from the body, and the machines which select various devices. Laboratory experiments show the properties of semi-permeable membranes which function in the kidneys and allow wastes to pass but restrict the passage of food materials. Content analysis charts demonstrate the difference between glomerular fluid and urine. Factors affecting the rate of urine formation, such as blood sugar content and external factors are also examined.