Water Balance Flashcards
What are electrolytes?
Soluble inorganic molecules whose ions conduct electricity in solution
How is water distributed throughout the body?
2/3 intracellular fluid, 1/3 extracellular fluid
What are colloids?
Proteins or other large molecules as a solute
What is osmolarity?
Number of osmolarity in a L of water
What is osmolality?
Number of osmoles dissolved in a kg of water
Define tonicity
The ability of a solution to affect a cell. Dependent on concentration & permeability of the membrane to the solute
What is an isotonic solution?
Concentration of electrolytes is equal inside and outside of the cell - no osmosis
What is a hypotonic solution?
Low concentration of salutes that don’t cross the membrane
What is a hypertonic solution?
High concentration of solute, low concentration of water. Water will move out of the cell to balance concentration.
How is water regulation controlled?
Controlled by the hypothalamus. Osmoreceptors, baroreceptors and anti diuretic hormone control water levels.
What is hydrostatic pressure?
The force exerted on the membrane by water/fluid in a resting cell - this will be stable.
What drives osmotic pressure?
The number of electrolytes on one side of the membrane, water always follow salts.
What is the role of sodium?
Nerve conduction, creates osmotic pressure
What is the role of potassium?
Nerve conduction, healthy muscles
What is the role of calcium?
Healthy bones and teeth, muscle contraction, nerve excitability
