Skip to main content
Back

Fluid, Electrolyte, and Acid-Base Balance in Anatomy & Physiology

Control buttons has been changed to "navigation" mode.
1/26
  • Body water content percentages in males and females

    Males are approximately 60% water and females are about 50% water due to differences in fat content.

  • Intracellular fluid compartment (ICF)

    Fluid within body cells, including cytosol and organelle matrices; makes up about 33% in males and 27% in females of body water.

  • Extracellular fluid compartment (ECF) components

    Includes interstitial fluid (fluid between cells), intravascular fluid (plasma), and other fluids like lymph and cerebrospinal fluid.

  • Difference in electrolyte composition between ECF and ICF

    ECF has higher Na+ and Cl-, while ICF has higher K+ and HPO42-.

  • Role of hydrostatic and colloid osmotic pressure in capillary exchange

    Hydrostatic pressure pushes fluid out at arteriole end; colloid osmotic pressure pulls fluid in at venous end due to plasma proteins.

  • Obligatory water output daily amounts

    Includes 1200 mL urine, 750 mL evaporation via skin, 400 mL evaporation via lungs, and 150 mL feces, totaling about 2500 mL/day.

  • Primary hormone regulating water balance

    Antidiuretic hormone (ADH) is secreted by the neurohypophysis to increase water reabsorption in kidneys when blood volume decreases.

  • Effect of atrial natriuretic peptide (ANP) on water and sodium balance

    ANP blocks ADH and aldosterone secretion, increasing urine output and reducing ECF volume by promoting sodium and water loss.

  • Aldosterone's role in sodium and water reabsorption

    Secreted by adrenal cortex when Na+ is low; increases Na+ reabsorption in kidneys, causing water to follow and reducing urine output.

  • Causes and effects of dehydration

    Caused by hemorrhage, burns, vomiting, diarrhea, sweating, or water deprivation; leads to hypertonic ECF causing cells to crenate.

  • Diabetes insipidus and its cause

    Chronic dehydration due to hyposecretion of ADH, resulting in excessive water loss.

  • Hypotonic hydration and its cellular effect

    Excess water intake or retention dilutes ECF, causing water to move into cells and potentially causing cell lysis.

  • Potassium regulation by aldosterone and ANP

    Aldosterone increases K+ secretion into urine; ANP decreases K+ secretion and may enhance K+ reabsorption.

  • Parathyroid hormone (PTH) effects on calcium and phosphate

    PTH raises blood Ca2+ by stimulating bone resorption and absorption; lowers blood phosphate levels.

  • Calcitonin effects on calcium and phosphate

    Calcitonin lowers blood Ca2+ by stimulating osteoblasts; raises blood phosphate levels.

  • Definition of acids and bases in body fluids

    Acids release H+ ions (proton donors); bases release OH- ions (proton acceptors), affecting pH levels.

  • pH scale and neutrality

    pH is the negative logarithm of H+ concentration; pH 7 is neutral with equal H+ and OH- ions.

  • Bicarbonate buffer system components

    NaHCO3 acts as a weak base; H2CO3 acts as a weak acid; buffers ECF by neutralizing strong acids and bases.

  • Phosphate buffer system location and function

    Important in ICF and urine; uses Na2HPO4 (weak base) and NaH2PO4 (weak acid) to maintain pH balance.

  • Protein buffer system mechanism

    Carboxyl groups release H+ (weak acid); amine groups accept H+ (weak base); buffers both ICF and ECF.

  • Compensations for metabolic acidosis

    Hyperventilation to reduce CO2 and kidney reabsorption of HCO3- with secretion of H+ to raise pH.

  • Causes of respiratory acidosis

    Hypoventilation from shallow breathing, chronic bronchitis, emphysema, narcotics; leads to increased CO2 and decreased pH.

  • Effects of hypernatremia and hyponatremia

    Hypernatremia (>145 mEq/L) causes thirst, coma; hyponatremia (<135 mEq/L) causes brain swelling, confusion, shock.

  • Symptoms of hyperkalemia and hypokalemia

    Hyperkalemia causes cardiac arrhythmias and muscle weakness; hypokalemia causes arrhythmias, muscle weakness, and confusion.

  • Role of lungs and kidneys in acid-base balance

    Lungs regulate CO2 levels; kidneys reabsorb or secrete H+ and HCO3- to maintain blood pH within normal range.

  • Edema causes and management

    Excess fluid in tissues caused by disease or medication; reducing salt intake can help minor cases.