Electrolytes Flashcards
What is a solute?
A substance dissolved in a solvent to create a solution
What are electrolytes?
Substances with molecules that dissociate or split into ions when placed in water
Are cations positively or negatively charged?
Positively charged
Are anions positively or negatively charged?
Negatively charged
What is osmotic pressure?
The “power” of a solution to draw water through a selectively permeable membrane
Across a selectively permeable membrane, will a greater osmotic pressure be exerted by the high concentration solution or the lower concentration solution?
The higher concentration solution will exert a higher osmotic pressure, drawing water towards itself through the membrane
Filtration pressure is the net of which two pressures?
Hydrostatic pressure and oncotic/colloid osmotic pressure
Hydrostatic pressure in capillaries is the result of what?
Blood pressure from the arterial system
Oncotic/colloid osmotic pressure in capillaries is the result of what?
The presence of proteins that cannot move out of the capillaries (primarily albumin)
Does hydrostatic pressure drive fluids into or out of the capillaries?
Hydrostatic pressure drives fluid out of capillaries
Does oncotic/colloid osmotic pressure drive fluids into or out of the capillaries?
Oncotic/colloid osmotic pressure drives fluids into capillaries
What is the tonicity of a solution with the same osmolarity as body fluids?
Isotonic
e.g. 0.9% NaCl
What is the tonicity of a solution with a higher osmolarity than body fluids?
Hypertonic
e.g. 3% NaCl
What is the tonicity of a solution with a lower osmolarity than body fluids?
Hypotonic
e.g. 0.45% NaCl
Low blood volume is called what?
Hypovolemia
High blood volume is called what?
Hypervolemia
The loss of water without electrolyte loss is called what?
Dehydration
When the concentration of electrolytes in blood is too low, this is called what?
Water intoxication (Overhydration)
What percentage of total body weight is from fluid?
60%
Of the fluid in the body, how much is intracellular?
2/3 of the fluid in the body is intracellular (40% of total body weight)
Of the fluid in the body, how much is extracellular?
1/3 of the fluid in the body is extracellular (20% of total body weight)
Of the extracellular fluid, how much is interstitial fluid?
3/4 of extracellular fluid in the body is interstitial fluid (15% of total body weight)
Of the extracellular fluid, how much is vascular?
1/4 of extracellular fluid is vascular (5% of total body weight)
What are the four extracellular fluid compartments?
Intravascular (cardiovascular system), Interstitial, Lymph and Transcellular (Serous fluid, synovial fluid etc.)
What is the healthy range for sodium blood concentration?
135-145 mEq/L
Is sodium mainly an extracellular cation or intracellular cation?
Extracellular
What roles does sodium play a part in?
Water balance (Where sodium goes, water flows), and transmission of nerve impulses
Is sodium stored in the body?
No, it must be consumed daily
A blood concentration of sodium above 145 mEq/L is called what?
Hypernatremia
A blood concentration of sodium below 135 mEq/L is called what?
Hyponatremia
Hyponatremia can cause what symptoms?
Drowsiness, confusion and varying effects on consciousness depending on severity (impaired neural impulses due to less sodium)
What is the healthy range for potassium blood concentration?
3.5-5.0 mEq/L
Is potassium mainly an extracellular or intracellular cation?
Intracellular
What roles does potassium play a part in?
Electrical conduction of nerve impulses (especially cardiac conduction), cell metabolism of glycogen and glucose
What can low potassium levels cause?
Arrhythmia
What can high potassium levels cause?
Cardiac arrest
Is potassium stored in the body?
Yes, in cells and bones
The sodium potassium pump does what?
It transports 3 intracellular sodium ions out of the cell and 2 extracellular potassium ions into the cell with every ATP phosphorylation, creating an electrical gradient across the cell membrane
What is a healthy range for blood calcium concentration?
8.5-10.5mg/dl (1% in extracellular fluid)
What roles does calcium play a part in?
Skeletal, smooth and cardiac muscle contraction and blood clotting
What does calcium need to be absorbed by the body? How does the body get this?
Vitamin D is required for calcium absorption, which requires sunlight for synthesis in the body
Is calcium stored in the body?
Yes, in cells and bones
What can cause hypocalcemia?
Vitamin D deficiency, burns (among other things)
What can cause hypercalcemia?
Hyperparathyroidism
What are some symptoms of hypercalcemia?
Increased musculoskeletal excitability, stupor (near unconsciousness or insensibility) and coma
What is a healthy range for blood phosphate concentration?
1.6-2.9 mEq/L
What roles does phosphate play a part in?
Metabolism of carbs, protein and fat, cellular metabolism (ATP and DNA), muscle, nerve and red blood cell function, acid base balance and calcium regulation
What is a low phosphate blood concentration called?
Hypophosphatemia
What is a high phosphate blood concentration called?
Hyperphosphatemia
What can cause hypophosphatemia?
Alcohol abuse, acid-base imbalance, increased urine output and decreased intestinal absorption
What can cause hyperphosphatemia?
Tissue trauma (damaged tissues may lock phosphate within them)
What is a healthy range for blood magnesium concentration?
1.5-2.5 mEq/L
What roles does magnesium play a part in?
Operation of the sodium potassium pump (allowing it to use ATP), Muscle relaxing, transmitting nerve impulses, regulating cardiac function, blood clotting and protein and DNA synthesis
What can cause hypomagnesium?
Alcohol abuse, diarrhoea, vomiting
What tachycardia can hypomagnesium cause?
Torsade De Pointes
What can cause hypermagnesium?
Too many antacids (antacids often contain magnesium)
What major role does bicarbonate play a part in?
Carbonic acid/acid-bicarbonate buffering system
Where is bicarbonate regulated and controlled?
In the kidneys, which reabsorb and excrete bicarbonate as needed
