Electrolytes Flashcards
Anion
A negatively charge ion, i.e. one that would be attracted to the anode in electrolysis.
Cation
A positively charged ion, i.e, one that would be attracted to the cathode in electrolysis.
Anion Gap
A measurement of the difference- or gap-between the negatively charged and positively charged electrolytes.
Active Transport
The process of moving molecules across a cellular membrane through the use of cellular energy.
Passive Transport
A type of membrane transport that does not require energy to move substances across cell membranes.
Electrolyte
The ionized or ionizable constituents capable of carrying an electric charge.
Extracellular Fluid
Body fluid that is not contained within cells.
Intracellular Fluid
Body fluid that is contained within the cells and cytosol.
Osmolality
A measure of the number of dissolved particles in a fluid. (i.e. sodium, potassium, etc.)
Osmolarity
The number of particles of solute per liter of solution.
Osmolal Gap
The difference between measured serum osmolality and calculated serum osmolality.
Diabetes Insipidus
A disorder of salt and water metabolism barked by intense thirst and heavy urination.
Polydipsia
Excess thirst
Anion
Electrolytes with a negative charge; moves towards the anode.
Cation
Electrolytes with a positive charge; move towards the cathode.
Anion Gap
A measurement of the difference- or gap-between the negatively charged and positively charged electrolytes.
Active Transport
A mechanism that requires energy to move ions across cellular membranes.
Ex: Na/K Pump
Passive Transport (Diffusion)
The passive movement of ions (no energy consumed) across a membrane.
Dependent on the size and charge of ion being transported.
Osmolality
Physical property of a solution that is based on the concentration of solutes expressed as milliosmoles/kg of solvent (w/w).
Extracellular Fluid
Accounts for 1/3 of the total body water and can be subdivided into intravascular ECF (plasma), and the interstitial cell fluid which surrounds the cells in the tissue.
Osmosis
The spontaneous passage or diffusion of water or other solvents through a semipermeable membrane.
Movement of solvent from low to high solute concentration.
Osmosis
The spontaneous passage or diffusion of water or other solvents through a semipermeable membrane.
Movement of solvent from low to high solute concentration.
Osmotic Pressure
The amount of pressure required to exactly oppose osmosis into any solution across a semipermeable membrane separating it from pure water.
Proportional to the number of dissolved solute particles per unit volume.
Osmotic Pressure
The amount of pressure required to exactly oppose osmosis into any solution across a semipermeable membrane separating it from pure water.
Proportional to the number of dissolved solute particles per unit volume.
Oncotic Pressure
Osmotic pressure when there is a higher concentration of protein on the plasma side than the interstitial side of the cell membrane.
Hydrostatic Pressure
Blood Pressure
Homeostasis
Maintenance of a steady state in the body of a relative constant concentration of ions, pH, and osmotic pressure in the various body fluids.
Homeostasis
Maintenance of a steady state in the body of a relative constant concentration of ions, pH, and osmotic pressure in the various body fluids.
What is the body’s response to variation in plasma osmolality under the following condition:
Increased plasma osmolality
(1) Increased stimulation of arginine vasopressin hormone (AVP), increases retention of water in body
(2) increased sensation of thirst, increases intake in water
What is the body’s response to variation in plasma osmolality under the following condition:
Decreased plasma osmolality
Decreased stimulation of arginine vasopressin hormone (AVP) - lose water
What is the body’s response to variation in plasma osmolality under the following condition:
Decreased renal perfusion pressure
Increase in angiotensin II - increase aldosterone and retain sodium and vasoconstrict vessels
What are five factors affecting blood volume?
(1) Renin-angiotensin system
(2) Volume receptors independent of osmolality stimulate the release of AVP, which conserves water by renal absorption
(3) Atrial natriuretic peptide (ANP) - released from the myocardial atria in response to volume expansion; promotes sodium excretion in the kidney
(4) Glomerular filtration rate (GFR) - increases with volume expansion and decreases with volume depletion
(5) Increased sodium in urine or plasma
What type of specimen should be used for osmolality analysis?
Serum or Urine
Why can’t plasma be used for osmolality?
The possibility of introducing osmotically active substances to the specimen from the anticoagulant.
The sample should be free of particulate matter to obtain accurate results.
For direct test osmolality, what is being tested?
The properties of freezing point, boiling point, and vapor pressure.
For an increase in osmolality, what will the outcome of the tests be?
Decrease in freezing point temperature and vapor pressure, and an increase in the boiling point temperature.
What is the reference interval for osmolality for both serum and urine?
Serum: 275-295 mOm/kg
Urine: 300 - 900 mOsm/kg
Osmolal Gap
(Direct Osmolality) - (Indirect Osmolality)
What does it mean if the osmolal gap is high?
That some osmotically active substance (other than Na, glucose, or BUN) is present in the serum or urine, or proteins are present in higher amounts than normal.