Fluid, electrolyte, and acid-base balance Flashcards
The movement of water across cell membranes.
Osmosis
The force created when 2 solutions of different concentrations are separated by selectively permeable membrane.
Osmotic pressure
Refers to the number of osmols (unit of osmotic pressure) per kilogram of solvent, which in this case is water.
Osmolality
The number of osmols per Liter of solvent.
Osmolarity
Refers to the level of osmotic pressure of a solution.
Tonicity
An administered solution that has the same osmolarity as blood plasma.
Isotonic solutuin
This solution pulls water from the cell to the extracellular fluid compartment causing cellular shrinkage.
Hypertonic solution
Solutions with a lower osmolarity than body fluids. Excess water moves into the cells, producing cellular swelling.
Hypotonic solution
When plasma proteins are too large to pass through the capillary membrane and hold the fluid in the intravascular space.
Oncotic pressure
The process by which fluid and solutes move together from an area of high pressure to an area of low pressure.
Filtration
The maintenance of fluid balance is controlled by several physiologic mechanisms what are they? RAT
Renin-angiotensin, mechanism\
Antidiuretic hormone (ADH)
Thirst Mechanism
A decrease in bodily fluid volume.
Hypovolemia
Electrolytes move in and out of the intracellular and extracellular spaces through what 3 things? DFA
- Diffusion
- Filtration
- Active transport
The movements of solutes across a selectively permeable membrane from areas of higher concentration to areas of lower concentration until equilibrium is reached.
Diffusion
What 4 factors influence the rate of diffusion? TMSM
Temperature, molecular weight, steepness of the concentration gradient, membrane permeability.
This type of diffusion occurs when a solute is unable to pass through a membrane and requires assistance with a carrier.
Facilitated diffusion
The transport of a solute from areas of lower to higher concentration. Give an example.
Active transport; exchange of sodium and potassium across the cell membrane facilitated by sodium-potassium pump.
What are the 5 major cations?
Sodium (Na), magnesium (Mg), potassium (K), calcium (Ca), and hydrogen (H). All positive.
What are the 3 major anions?
Chloride (Cl), bicarbonate (HCO), and phosphate (PO); all negative.
Which two electrolytes are found primarily inside the cell?
Potassium and Phosphate
Which electrolytes are found in higher concentration in intravascular fluid like blood plasma?
Sodium and Chloride
Excessive fluid loss can lead to decreased circulation volume which directly affects what?
Cardiac output
Fluid volume excess leads to an increase in circulating fluid causing an increase to __________.
The workload of the heart
This occurs when their is an excessive loss or inadequate intake of fluid. What are the 2 types?
Fluid volume deficit; Isotonic and hypertonic
Occurs when water and sodium are lost at the same rate. Circulating volume decreases but serum osmolarity remains the same.
Isotonic fluid deficit (hypovolemia)
As fluid loss continues, the circulating fluid volume decreases and serum osmolarity increases.
Hypertonic fluid loss deficit (dehydration)
A 2% loss of percentage of total body weight is considered what ?
Mild dehydration
A 5% loss of percentage of total body weight is considered what?
Moderate dehydration
An 8% loss of percentage of total body weight is considered what?
Severe dehydration
A 15% loss of percentage of fluids to total body weight is considered what?
Life-threatening dehydration, usually fatal