A four-part image is presented. The first part shows the distribution of body solids and fluids in an average lean adult female and male. The total body mass of a female consists of 45 percent solids and 55 percent fluids. The total body mass of a male consists of 40 percent solids and 60 percent fluids. Total body fluid consists of two thirds intracellular fluid, ICF, and one third extracellular fluid, ECF). Extracellular fluid consists of 80 percent interstitial fluid and 20 percent plasma. The second part shows a blood capillary beneath many tissue cells. The tissue cells have intracellular fluid. The blood capillary and tissue cells are surrounded by the interstitial fluid. Water and electrolytes, ions of sodium, potassium, and chlorine, are present in the blood capillary and interstitial fluid. The structure of water is represented by a ball-and-stick model with a red ball and two white balls. Electrolytes and water link to more detailed screens. Text at the bottom of the screen reads; Body fluids consist primarily of water with dissolved substances. The most abundant of the dissolved substances are proteins and electrolytes.