Solutions, Body Fluids, and Electrolytes - Chapter 13 - Elsevier PDF

Summary

Chapter 13 of the textbook covers solutions, body fluids, and electrolytes. It discusses topics such as defining solutions, osmotic pressure, and the role of electrolytes like sodium, chloride, and bicarbonate in the body. The content presents key concepts related to maintaining body fluid balance and the impact of electrolyte imbalances.

Full Transcript

Chapter 13 Solutions, Body Fluids, and Electrolytes Copyright © 2017 Elsevier Inc. All Rights Reserved. Definition of a Solution  Solution  A stable mixture of two or more substances in a single phase that cannot be separated using a centrifuge ...

Chapter 13 Solutions, Body Fluids, and Electrolytes Copyright © 2017 Elsevier Inc. All Rights Reserved. Definition of a Solution  Solution  A stable mixture of two or more substances in a single phase that cannot be separated using a centrifuge  Solute  A substance dissolved in a solution (sugar in coffee – yum)  Solvent  Any liquid in which another substance can be dissolved Copyright © 2017 Elsevier Inc. All Rights Reserved. 2 Osmotic Pressure of Solutions  It is important to note that solutions have the ability to exert pressure.  Semipermeable membrane: allows solvent molecules to pass. Example is capillary wall Copyright © 2017 Elsevier Inc. All Rights Reserved. 3 4 Osmotic Pressure of Solutions  Osmotic (oncotic) pressure of solutions  Redistribute solvent molecules for same concentration on both sides of membrane  Water is distributed in body via osmosis  Tonicity describes osmotic force exerted by solution Isotonic: solutions with tonicity similar to body solutions, (i.e., 0.9% solution of NaCl—normal saline) Hypertonic: greater tonicity than 0.9% NaCl –draws fluids out of the cells Hypotonic: less tonicity than 0.9% NaCl - water is drawn into the cell Most cells exist in this environment Various tonicities facilitate movement of water, nutrients, and other substances through body http://www.youtube.com/watch?v=SSS3EtKAzYc 5 Copyright © 2017 Elsevier Inc. All Rights Reserved. Solutions (cont.)  Quantifying solute content & activity  2 ways to quantify: Actual weight in g or mg  Equivalent weights Defines amounts of substances having equal chemical combining forces Generally stated in gram equivalent weight (gEq) or milliequivalent (mEq) 6 Solutions (cont.)  Milligram Equivalent Weights  Concentrations of most chemicals in the body are small. mEq is a term used to express the minute values. 7 Electrolytic Activity and Acid- Base Balance (Cont.)  pH scale:  Used to describe concentration of H+ in solution  >7 has less acid or more base than water = alkaline 