Disorders Of Fluid And Electrolyte Flashcards
Tonicity`
The effect that the osmotic pressure of a solution with impermeable salutes exerts on cells
Isotonic solution
Same concentration of fluid and blood. Normal saline: .9
Hypotonic solution
Solution has a lot of water.. the cells swell
Move out of the tissues: dehydration
Hypertonic solution
Many more particles than blood. Pulls fluid from the tissue.
Hydrostatic pressure
Fluid pushing against the vessel trying to get out.
Colloid Osmotic pressure
Particles within the vessel trying to hold fluid in and keep balance in that way.
Lymph drainage
Drains excess things into the lymph system
Serum osmolality
Tells the hypothalamus that there are more particles; thirsty.
Blood volume
How much fluid we have. When there’s not enough it tells the hypothalamus to release ADH. Which then then causes reabsorption of water by the kidney
High osmolarity causes
Thirst: increased water intake
ADH release: water reabsorbed from the urine
Low Osmolality causes
Lack of thirst: decrease water intake
Decreased ADH release: Water lost in urine
Diabetes Insipidus
Neurogenic Nephrogenic Excess urine output Hypertonic dehydration DDAVP: desmopressin acetate Thiazide diuretics: paradoxical effect Stop urine output.
Neurogenic
Decreased ADH production: head injury
Nephrogenic
Decreased renal response to ADH: Kidney isn’t responding to ADH
SIADH: Syndrome of Inappropriate ADH
Failure of hypothalamus Transient: stress, surgery, lung tumors Excessive ADH secretion Decreased urine output Dilution also hyponatremia Treatment: Water restriction, diuretics, aquaretics
What are electrolytes
Substances that dissociate in solution to form charged particles or ions
Electrolytes are essential in metabolic processes
Sodium
Normal level is 135-145
Major electrolyte in the blood
Neurons can protect themselves form what
Hypertonic dehydration
Neurons
Create internal solutes that hold the water inside the cell.
Neuron response to hypertonicity
Increased blood osmolality can cause cells to shrink they lose water to the vascular space.
Neve cells procure intracellular osmoles to keep their osmolality balanced with the blood
Neuron response to hypertonicity
If the blood returns to isotonic to fast the nerve cells are hyperosmolar to the blood and gain water: swelling
Cerebral edema: can lead to brain damage or herniation
Potassium
Normal level is 3.5-5.0
Controls cell resting potential
Needed for Na+/K+ pump
Exchanged for H+ to buffer changes in blood pH
Hyperkalemia
Raises resting potential toward threshold. Cells fire more easily. Potassium in the blood HR increased wont respond normally Tachycardia
Hypokalemia
Lowers resting potential away form threshold
Cells fire less easily
Bradycardia HR decreases
Not enough potassium in the blood
Alkalosis (potassium as a buffer)
Not enough H+ ions in the blood
Cells release H+ ions to fix this imbalance and take up K+ ions in exchange
Blood K+ will decrease
Hypokalemia
Acidosis (potassium as a buffer)
Too many H+ ions in the blood
Cells keep H+ ions inside to fix the imbalance and release K+ in exchange
Blood K+ will increase
Hyperkalemia
Calcium
Normal range 8.5-10.5
Clottin
Extracellular calcium
Blocks Na+ gates in nerve and muscle cells controls excessive firing (Tetany)
Intracellular calcium
Needed for all muscle contraction (cardiac and skeletal)
Parathyroid hormone
Increases serum Ca+
Calcitonin
Decreases serum Ca+
Hypercalcemia
Blocks more Na+ gates
Nerves are less able to fire
Hypocacemia
Blocks fewer Na+ gates
Nerves fire more easily
Hypokalemia: Neuromuscular
Parenthesis, cramps, hyperrelexia, tetanyu
Hypocalcemia: CV
Hypotension, prolonged QT
Hypocalcemia: Skeletal
Osteoporosis
Hypercalcemia: Renal
Renal insufficiency
Kidney stones
Hypercalcemia: Neuromuscular
Ataxia, weakness, lethargy, coma
Hypercalcema: CV
Hypertension
Magnesium
Normal Level: 1.8-2.7
Cofactors in enzymatic reactions:
- ATP, DNA replication, mRNA production
Regulates Ca+ levels by binding to receptors
Interdependent with K+
-affects heart rhythm- life threatening (cardiac dysrthmias)
Hypomagnesim: Neuromuscular
Weakness parathesias, Personality changes
Hypomagnesim: CV
Cardiac arrhythmias
Hypermagnesemia: Neuromuscular
Lethargy, hyporeflexia, confusion, coma
Hypermagnesemia: CV
Hypotension, Arrhythmias, arrest.
Phosphorous
Bone Red blood cell Acid/base Many enzymatic processes Reciprocal relationship with Ca+ Regulated by kidney