Crocodile Tears and Other Liquids

This chapter focuses on the balance of water intake and discharge in humans and animals. It explains how the intake of water by a human being is discharged by means of removal by kidneys and evaporation from the skin surface. It also describes the seriousness of reduction of water intake. It explains how sea birds can drink salt water and remove excess of salt by “weeping.” The chapter discusses the various studies and indicators used to measure water in humans. The chapter also describes how the constancy of volume and composition of liquids are maintained in an organism. It further explains the function of the kidneys and Henle's loop. It talks about ultrafiltration and equations for measuring urine concentrations. Cryobiology and biological antifreezes are detailed next. This chapter also describes the mechanism that many animals use for survival at extremely low temperatures. It discusses other types of solutions present in animals that act as natural antifreeze. Finally it explains how plants that survive cold temperatures also possess antifreeze.