Water Balance and Electrolytes. Flashcards
Most dominant extracellular ion?
Sodium.
Balance of Sodium, Potassium and Calcium in and out of the cell?
Sodium = higher out of the cell. Potassium = higher within the cell. Calcium = higher out of the cell.
Other important electrolytes?
Magnesium, Chloride, Bicarbonate and Phosphorus.
Amount of water within the body?
32 - 40 litres, 60% of the body.
Features of water.
Universal solvent, Joint and organ lubrication, ability to retain and absorb heat.
What is diffusion.
The movement of molecules from high to low concentration, allowing substances to move in and out of cells.
What affects diffusion?
Temperature, Weight, Concentration gradient, Membrane surface area and permeability.
Define Osmosis.
The diffusion of water across a semi-permeable membrane.
What is a solution?
A homogeneous mixture of 1 or more substances, liquids and solutes.
The three types of solutions…
Aqueous, Colloids and Suspensions
Define Osmolarity.
The number of osmoles per L of solution.
Define Osmolality.
The number of osmoles per Kg of solution.
What is hypertonicity?
More solute, Less water causing the cell to shrivel.
What is hypotonicity?
Low solute, More diluted causing the cell to swell.
Treatments for dehydration…
0.9% saline solution, 5% glucose, gelofusine and fluid therapy.
