Water and electrolytes Flashcards
What is hydrostatic pressure?
it is the pressure exerted by an fluid at equilibrium due to the force of gravity
Pressure= force/area
What is the concentration of solutions?
amount of solute per unit volume of solvent
concentration= amount solute/volume solvent
Ion
atom or group of atoms with an electrical charge
cation +
anion-
Valence electrons
the number of electrons in an atom’s outermost energy level (shell)
Valency
the combining power of an atom
the absolute number of electrons that are gained,
lost, or borrowed in order to have a full outermost
energy level
Elements with 4 electrons will share them such as
Carbon
Examples:
oxygen has 6 valence electrons so its valency is 2
sodium has 1 valence electron so its valency is 1
osmosis
the net diffusion of water across a membrane
Osmotic pressure
the pressure that must be applied to a solution to prevent the net flow of water into it
the amount of pressure required to prevent
osmosis is called the osmotic pressure
per k= (m x v^2)/2 large and small particles exert the
same osmotic pressure
Osmotic pressure is directly related to
the solute concentration (osmolality)
What contributes the most to osmotic pressure of body fluids?
electrolytes; they determine the distribution of body water
What is an osmol?
one mole of solute particles dissolved in a solution
indicator of osmotic activity
the term osmole refers to the number of osmotically active particles rather than the molar
1 mole/1 L is equal to
1 osmol/ 1L or 1 osmM
1 osmole is equivalent to
1 mole which is equal to 6.02 x 10^23 particles
What osmolality do we use when referring to the body?
we utilize milliosmoles for body fluids
1 mOsm= 1/1000 osmoles
What is osmolarity?
the osmotic concentration of a solution expressed as OSMOLES of solute per LITER of solution
What is osmolality?
the osmotic concentration of a solution expressed as OSMOLES per KG of solution
285-295 mOsm/kg is normal osmolality for adults
275-290 mOsm/kg is normal osmolality for
children
What is an isotonic solution?
the solution has the same solute concentration as our cells
0.9 NS or LR
What is a hypotonic solution?
the solution has less solute concentration than our cells so water will want to move into cells and cause them to burst
ex.: D5 or .45 NS
What is a hypertonic solution?
the solution has more solute concentration than our cells so water will want to move out of cells and cause them to shrink
Ex. 3%