T2: Water and Electrolyte Balance Part 1 Flashcards
4 factors wich must be controlled in the human body to maintain homeostasis
- water balance between fluid compartments
- Electrolyte balance
- pH - 7.40
- Temperature - 37C
All water within cell membranes; the medium though which CHEMICAL REACTIONS OF CELLULAR METABOLISM occur
Definition of intracellular fluid
major ions/constituents in intracellular fluid
- Cations: potassium and magnesium
- Anions: protein, organic phosphates, and sulfates
- Low concentrations of: sodium, chloride, bicarbonate
All water outside of cell membranes; the medium though which all METABOLIC CHANGES occur
Definition of extracellular fluid
major ions/constituents in extracellular fluid
interstitial Fluid and Plasma
The directly measurable plasma is known as what?
Intravascular fluid
major ions/constituents in intravascular fluid
- Large amount of proteins
- High concentrations: sodium and chloride
- Moderate concentrations: bicarbonate
- Low concentrations: calcium, magnesium, phosphate, sulfate, potassium, organic acids
Fluid that directly bathes the cells of body includes pericardial, pleural, peritoneal, and synovial body fluids; cannot be sampled for direct measurement
Definition of interstitial fluid
major ions/constituents in interstitial fluid
High: sodium and chloride
Medium: bicarbonate
Low: NO proteins
The force that tends to move water from dilute solutions to concentrated solutions
definition of osmotic pressure
How do osmotic pressure differences maintain the composition of extracellular and intracellular fluids?
*Predominance of K in the intracellular fluid and Na in the extracellular fluid PLUS plasma proteins that are the major contributors to the osmotic pressure between these compartments
What maintains electroneutrality between compartments?
Gibbs-Donnan Equilibrium
How does the Gibbs-Donnnan equilibrium maintain the composition of extracellular and intracellular fluids
It maintains the electroneutrality between compartments by keeping the anion total equaling the total cations (the use of non-diffusible anions is important)
3 chemical constituents that contribute to osmotic pressure differences between EXTRACELLULAR and INTRACELLULAR fluid compartments
Potassium, sodium, and plasma proteins
3 means by which water balance is maintained between INTERSTITIAL and INTRACELLULAR fluid compartments
- membrane characteristics
- colloid osmotic pressure
- Na-K-ATPase pump