The document discusses body fluids and their composition. It states that the water content in the body is divided into extracellular fluid (ECF) and intracellular fluid (ICF). ECF makes up about 1/3 of total body water and contains ions and nutrients outside cells. ICF makes up about 2/3 of total body water and contains fluid inside cells. It provides examples of how to calculate total body water and compares the electrolyte compositions of ECF and ICF.

1. BODY FLUIDS

7. Differences between ECF & ICF ECF Anions : Cl - (108) HCO 3 - (24) Cations : Na + (142 mmol/L ) K + (4.2) Mg 2+ (0.8) Nutrients : O 2 , glucose, fatty acids, & amino acids. Wastes : CO 2 , Urea, uric acid, excess water, & ions. ICF Anions : Cl - (4) HCO 3 - (10) Phosphate ions Cations : Na + (14) K + (140) Mg 2+ (20) Nutrients : High concentrations of proteins.

8. COMPOSITION OF BODY FLUIDS CATIONS (mmol/l) Plasma Interstitial Intracellular Na 142 139 14 K 4.2 4.0 140 Ca 1.3 1.2 0 Mg 0.8 0.7 20 ANIONS (mmol/l) Cl 108 108 4.0 HCO3 24.0 28.3 10 Protein 1.2 0.2 4.0 HPO4 2.0 2.0 11

12. Basic Definitions Tonicity Osmolality Physiological term (effective Os P relative to plasma) Solutes that do not cross the cell membrane only counts Chemical term All solutes contributes to Osmolality 2 x Na + + Glucose 285 mOsm/kg Na + x 2 + glucose + BUN 290 mOsm/kg

26. Hormonal Regulation of Blood Volume 27-

27. Hormonal Regulation of Blood Volume 27-

28. Regulation of ECF Volume 27-

29. Regulation of Water Intake Figure 27.5