body fluid is contained within the walls of the cells. Plasma in the blood is an example of this type of body fluid. This term best describes the minerals (sodium, potassium, chloride and phosphorus) when they are in water as charged particles called ions. Which of the following statements bests describes a physiological benefit of the high heat capacity of water? Cell membranes are freely permeable to electrolytes. Water flows in this direction when the electrolyte concentration is higher outside the cell than it is within the cell. Which of the following mineral salts is critical to generation, transmission and completion of nerve impulses? The flow of this mineral in and out of muscle cells makes muscle contraction and relaxation possible. This stimulates the thirst mechanism. When you are dehydrated the hypothalamus signals this organ that works to prevent fluid loss and avoid dehydration effects. Which of the following statements about metabolic water is true? What is the water AI (Adequate Intake) for a 40 year old man? Hyponatremia is associated with inadequate blood levels of this mineral. Studies show that the caffeine content of coffee causes mild dehydration. To regulate fluid balance, this positively charged ion is exchanged across cell membranes with potassium. This organ removes excess sodium from the body. Unfortunately intake of this mineral that helps you maintain a lower blood pressure is below recommendations for most people living in the U.S. This is the primary source of dietary chloride. This mineral found inside cells works with potassium to maintain fluid balance.