Question

on average, the body is composed of about 60% water found both within the cells (intracellular fluid) and outside the cells (extracellular fluid). the extracellular fluid includes interstitial fluid, which surrounds the cells, and other cumulative body fluids such as lymph, cerebrospinal fluid, and blood plasma. two major extracellular fluid compartments, interstitial fluid and blood plasma, are similar in chemical composition in that they both have high concentrations of sodium, chloride, calcium, and bicarbonate. the blood plasma differs in that proteins are found in a much higher concentration here than in the interstitial fluid. the capillaries allow for water and ions to move between these environments; however, large proteins are unable to cross the capillary wall. water moves between these fluid compartments by osmosis in response to changes in osmolarity. net water movement always occurs from high to low water concentration, and this fluid movement continually occurs in response to variations in fluid intake and fluid output. intravenous (iv) solutions are administered directly into the veins through either a syringe or intravenous catheter. an iv saline solution of 0.9% nacl is isotonic, and under normal conditions, does not cause a net shift in fluids between the interstitial fluid and the blood plasma. both hypertonic and hypotonic iv solutions may be carefully administered to induce the movement of water into and out of interstitial fluid compartments. 1. water you drink is absorbed into the blood from the digestive tract. an increase in water intake causes a(n) _ in the plasma osmolarity. decrease increase 2. an iv solution of 0.45% nacl is _ and induces the movement of water ___. hypotonic; into cells hypotonic; out of cells hypertonic; into cells hypertonic; out of cells

Explanation:

1. Osmolarity is related to the concentration of solutes in a solution. When water intake increases, the amount of solutes per unit volume of plasma decreases, thus plasma osmolarity decreases.
2. A 0.45% NaCl IV - solution has a lower solute concentration compared to the body's cells and extracellular fluids. Such a solution is hypotonic. In a hypotonic environment, water moves into the cells due to osmosis (from an area of higher water concentration outside the cells to an area of lower water concentration inside the cells).

Answer:

1. decrease
2. hypotonic; into cells