Copyright © 2009 Wolters Kluwer Health | Lippincott Williams & Wilkins Memmler’s The Human Body in Health and Disease 11 th edition Chapter 21 Body Fluids

Copyright © 2009 Wolters Kluwer Health | Lippincott Williams & Wilkins The Importance of Water Body fluid maintenance Thirst mechanism maintains volume Kidney activity regulates volume and composition Hormones regulate fluid volume and electrolytes Buffers, respiration, and kidney function regulate pH

Copyright © 2009 Wolters Kluwer Health | Lippincott Williams & Wilkins Fluid Compartments Intracellular fluid (ICF) –Two-thirds to three-fourths of all body fluids Extracellular fluid (ECF) –Interstitial fluid –Blood plasma –Lymph –Fluid in special compartments

Copyright © 2009 Wolters Kluwer Health | Lippincott Williams & Wilkins Main fluid compartments showing relative percentage by weight of body fluid. Fluid percentages vary but total about 60% of body weight. Fluids are constantly exchanged among compartments, and each day fluids are lost and replaced. Zooming In: What are some avenues through which water is lost?

Copyright © 2009 Wolters Kluwer Health | Lippincott Williams & Wilkins Checkpoint 21-1: What are the two main compartments into which body fluids are grouped?

Copyright © 2009 Wolters Kluwer Health | Lippincott Williams & Wilkins Water Balance Water gain from –Beverages –Food –Cellular respiration Water loss from –Kidneys –Skin –Lungs –Intestinal tract

Copyright © 2009 Wolters Kluwer Health | Lippincott Williams & Wilkins Checkpoint 21-2: What are three routes for water loss from the body?

Copyright © 2009 Wolters Kluwer Health | Lippincott Williams & Wilkins Sense of Thirst Control center for thirst Located in hypothalamus Regulates total fluid volume Excessive thirst -- polydipsia

Copyright © 2009 Wolters Kluwer Health | Lippincott Williams & Wilkins Checkpoint 21-3: Where is the control center for the sense of thirst located?

Copyright © 2009 Wolters Kluwer Health | Lippincott Williams & Wilkins Electrolytes and Their Functions Conduct electrical current in solution Positive ions (cations) –Sodium –Potassium –Calcium Negative ions (anions) –Phosphate –Chloride

Copyright © 2009 Wolters Kluwer Health | Lippincott Williams & Wilkins Checkpoint 21-4: What is the main cation in extracellular fluid? In intracellular fluid? Checkpoint 21-5: What is the main anion in extracellular fluid?

Copyright © 2009 Wolters Kluwer Health | Lippincott Williams & Wilkins Electrolyte Balance Kidneys do majority of balancing Hormones involved –Aldosterone (adrenal cortex) –Antidiuretic hormone (ADH) (pituitary) –Parathyroid hormone (parathyroid & thyroid glands) –Calcitonin hormone (thyroid) –Atrial natriuretic peptide (ANP) (from the heart)

Copyright © 2009 Wolters Kluwer Health | Lippincott Williams & Wilkins Checkpoint 21-6: What are some mechanisms for regulating electrolytes in body fluids?

Copyright © 2009 Wolters Kluwer Health | Lippincott Williams & Wilkins Question: When blood concentration of sodium rises, the pituitary secretes what hormone? a. ANP b. ADH c. calcitonin

Copyright © 2009 Wolters Kluwer Health | Lippincott Williams & Wilkins Answer: b. ADH (antidiuretic hormone)

Copyright © 2009 Wolters Kluwer Health | Lippincott Williams & Wilkins Acid–Base Balance pH scale measures hydrogen ion (H+) concentration Body fluids have normal pH of 7.35 to 7.45 Three-tenths of a point shift in either direction is fatal

Copyright © 2009 Wolters Kluwer Health | Lippincott Williams & Wilkins Regulation of pH Buffer systems accept or release ions as needed –Bicarbonate –Phosphate –Proteins Respiration provides short-term regulation Kidney function provides long-term regulation

Copyright © 2009 Wolters Kluwer Health | Lippincott Williams & Wilkins Checkpoint 21-7: What are three mechanisms for maintaining the acid–base balance of body fluids?

Copyright © 2009 Wolters Kluwer Health | Lippincott Williams & Wilkins Abnormal pH Acidosis –pH less than 7.35 –Depressed nervous system Alkalosis –pH greater than 7.45 –Excited nervous system Origins –Respiratory—change in blood CO2 –Metabolic—change in other acids

Copyright © 2009 Wolters Kluwer Health | Lippincott Williams & Wilkins Checkpoint 21-8: What are the conditions that arise from abnormally low or high pH of body fluids?

Copyright © 2009 Wolters Kluwer Health | Lippincott Williams & Wilkins Disorders of Body Fluids Edema Water intoxication Effusion Ascites Dehydration

Copyright © 2009 Wolters Kluwer Health | Lippincott Williams & Wilkins Checkpoint 21-9: What is edema?

Copyright © 2009 Wolters Kluwer Health | Lippincott Williams & Wilkins Question: What is effusion? a. accumulation of excess fluid in intercellular spaces b. fluid leakage into a cavity c. deficit of body fluids

Copyright © 2009 Wolters Kluwer Health | Lippincott Williams & Wilkins Answer: b. fluid leakage into a cavity

Copyright © 2009 Wolters Kluwer Health | Lippincott Williams & Wilkins Fluid Therapy Fluids administered intravenously Normal (.9%) saline 5% dextrose in.45% saline 5% dextrose in water Ringer lactate solution Serum albumin 25% Nutritional solutions

Copyright © 2009 Wolters Kluwer Health | Lippincott Williams & Wilkins End of Presentation