CHAPTER 26: FLUID & ELECTROLYTE OUTLINE G. LEWIS
Be sure to read the chapter carefully. Read the objectives listed below, chapter summary,
and do the questions at the end of the chapter. You may wish to use this outline, the
we bsite, and the CD IP tutorial to prepare for lecture and tests. Check and review your
notes daily. The outline may not follow the lecture/text exactly.
1. List the factors that determine body water content and describe the effect of each.
2. Indicate the relative fluid volume and solute composition of the fluid compartments of the
3. Contrast the overall osmotic effects of electrolytes and non-electrolytes.
4. Identify some factors that determine fluid shifts in the body.
5. Explain how water enters and leaves the body.
6. Describe the feedback mechanisms that regulate water intake and hormonal controls of water
output in urine.
7. Explain the importance of obligatory water loss.
8. Describe possible causes and consequence of dehydration, hypotonic hydration, and edema.
9. Describe how electrolytes are lost from the body.
10. Explain the importance of sodium electrolyte balance and note its relationship to
11. Describe the mechanisms involved in regulating sodium and water balance.
12. Describe how potassium, calcium, and other electrolyte balance of plasma is regulated.
13. List important sources of acids in the body.
14. Name the 3 major chemical buffer systems of the body and describe how they operate to
resist pH changes.
15. Explain the influence of the respiratory system on acid-base balance.
16. Explain how the kidneys regulate hydrogen and bicarbonate ion concentrations in the blood.
17. Distinguish between acidosis and alkalosis resulting from respiratory and metabolic factors.
18. Describe the importance of respiratory and renal compensations to acid-base balance.
19. Discuss reasons for infants and elderly being at risk for fluid and electrolyte imbalances.
FLUID, ELECTROLYTE, AND ACID-BASE BALANCE
I. Body Fluids
A. Body Water Content
1. Total body water is a function of –
a. Due to their low body fat –
b. The body water content of men is about –
2. Body water declines throughout life –
B. Fluid Compartments –
1. Intracellular Fluid -
2. Extracellular Fluids -
a. Plasma -
b. Interstitial fluid -
C. Composition of Fluids
a. Electrolytes -
b. Non-electrolytes -
c. Electrolytes have greater osmotic –
2. Comparison of extracellular and intracellular fluids (cations/anions)- see chart
D. Movement of fluids between compartments
1. Anything that changes solute –
2. Hydrostatic pressure forces –
3. Movement of water between the interstitial fluid and –
4. Ion fluxes between the interstitial and –
II. Wate r Balance
A. For the body to remain properly hydrated -
1. Most water enters the body –
2. Water output is due to -
B. Regulation of water Intake
1. The thirst mechanism is –
2. Thirst is quenched as the –
C. Regulation of Water Output
1. Drinking is –
2. Beyond obligatory –
D. Influence of ADH
1. The amount of water reabsorbed –
a. When ADH levels are low –
b. When ADH levels are high -
3. Role of the hypothalamus –
E. Disorders of Water Balance
1. Dehydration -
2. Hypotonic Hydration -
3. Edema -
III. Electrolyte Balance
A. Central Role of Sodium in Fluid and Electrolyte Balance
1. Sodium is the most –
2. Since all body fluids are in –
B. Regulation of Sodium Balance
1. Influence of Aldosterone -
2. Renin-Angiotensin mechanism –
3. Cardiovascular System Baroreceptors -
4. Estrogens -
5. Influence and Regulation of Atrial Natriuretic Factor
6. Influence of other hormones (glucocorticoids)
C. Regulation of Potassium Balance
1. Potassium is critical to the maintenance of –
2. Regulatory site – cortical collecting duct -
3. Influence of plasma potassium -
4. Aldosterone levels -
D. Regulation of Calcium and Phosphate Balance
1. Parathyroid Hormone
a. Bones -
b. Small intestine -
c. Kidneys -
2. Influence of Calcitonin –
E. Regulation of other anions -
IV. Acid-Base Balance
A. Abundance of hydrogen ions -
1. Alkalosis -
2. Acidosis -
B. Chemical Buffer Systems
1. A buffer system is –
2. Bicarbonate Buffer System –
a. When a strong acid is added –
b. When a strong base is added –
c. Bicarbonate concentration of –
3. Phosphate Buffer System -
4. Protein Buffer System -
C. Respiratory System Regulation of Hydrogen Ion Concentration
1. Carbon dioxide from –
2. When Hypercapnia –
3. When blood pH rises -
D. Renal Mechanisms of Acid-Base Balance
1. Only the kidneys can rid the body –
a. Bicarbonate ions can be conserved from filtrate – (reabsorption)
b. Type A intercalated cells, excrete H+, generate new bicarbonate Ions
c. Ammonium ions are weak acids –
d. Bicarbonate ion secretion when the body is in alkalosis –
E. Abnormalities of Acid-Base Balance
1. Respiratory Acidosis -
2. Respiratory Alkalosis -
3. Metabolic Acidosis -
4. Metabolic Alkalosis -
5. Effects of Acidosis or Alkalosis -
6. Respiratory and Renal Compensation -
V. Developmental and Aging Aspects of Fluid, Electrolyte, & Acid-Base Balance
A. Early Development
B. Childhood -