Fluids and Electrolytes, Acids and Bases

Flashcards for vocabulary review.

Total Body Water (TBW)

60% of body weight in adults

Intracellular Fluid

Fluid within cells.

Extracellular Fluid

Fluid outside of cells; includes interstitial fluid, intravascular fluid, and transcellular fluids.

Interstitial Fluid

Fluid between cells.

Intravascular Fluid

Fluid within blood vessels.

Transcellular Fluids

Includes synovial fluid, CSF, GI fluids, pleural fluids, peritoneal fluids, and urine.

Diffusion

The movement of a solute from an area of higher concentration to an area of lower concentration.

Osmosis

The movement of water through a semipermeable membrane from a lower solute concentration to a higher solute concentration.

Hydrostatic Pressure

Pushes water out of capillaries (filtration).

Oncotic Pressure

Pulls water into capillaries (reabsorption).

Edema

Excessive accumulation of fluid within the interstitial spaces.

Effusion

Localized edema

Anasarca

Generalized edema

Aldosterone

Hormone that regulates sodium balance by promoting sodium reabsorption.

Renin-Angiotensin-Aldosterone System (RAAS)

Compensatory mechanism used to replenish blood volume and raise blood pressure.

Renin

Enzyme secreted by the kidneys in response to low renal perfusion; initiates the RAAS.

Angiotensin II

A powerful vasoconstrictor produced by the conversion of angiotensin I by ACE.

Natriuretic Peptides

Involved in decreasing tubular reabsorption and promoting urinary excretion of sodium.

Antidiuretic Hormone (ADH)

Regulates water balance by increasing water reabsorption by the kidneys.

Sodium (Na+)

Primary extracellular cation; regulates osmotic forces and water balance.

Chloride (Cl-)

Primary extracellular anion; provides electroneutrality.

Isotonic

Solute concentration is equal to that of cells.

Hypotonic

Has a lesser concentration of sodium than cells; fluid shifts out of the intravascular space.

Hypertonic

Has a greater concentration of sodium than cells; draws fluid into the intravascular space.

Hypovolemia

Isotonic fluid loss.

Hypervolemia

Isotonic fluid excess.

Hypernatremia

Increased osmolality (>294 mOsm/kg).

Hyponatremia

Decreased osmolality (<280 mOsm).

Potassium (K+)

Major intracellular electrolyte; maintains normal cardiac rhythms, facilitates glycogen/glucose deposition, skeletal and smooth muscle contraction.

Hypokalemia

Potassium level <3.5 mEq/L.

Hyperkalemia

Potassium level >5.5 mEq/L.

Calcium (Ca+)

Normal value = 8.8 to 10.5 mg/dl. Necessary for metabolic processes, structure of bones and teeth, blood clotting, hormone secretion, etc.

Hypocalcemia

Decreased calcium concentration (<8.5 mg/dL).

Hypercalcemia

Increased calcium concentration (>10.5 mg/dL).

Phosphate

Normal value = 2.5-4.7 mg/dl. Provides energy for muscle contraction (as ATP).

Hypophosphatemia

Decreased phosphate concentration (<2.5 mg/dL).

Hyperphosphatemia

Increased phosphate concentration (>4.7mg/dL).

Magnesium

Normal value = 1.5 to 2.5 mEq/L. Increases neuromuscular excitability, role in smooth muscle contraction and relaxation.

Hypomagnesemia

Decreased magnesium concentration (<1.5mg/dL).

Hypermagnesemia

Increased magnesium concentration (>3.0 mg/dL).

Acid

A substance that donates H+.

Base

A substance that accepts H+.

Acidosis

Systemic increase in H+ concentration or decrease in bicarbonate (base).

Alkalosis

Systemic decrease in H+ concentration or increase in bicarbonate (base).