Fluid and Electrolyte Balance Flashcards

Vocabulary flashcards for key terms and definitions related to fluid and electrolyte balance.

Fluid and Electrolyte Balance

Essential for homeostasis and maintaining a favorable environment for cells. Water and electrolyte content must be in precise balance.

Total Body Water (Newborn)

75% to 90% of body weight

Total Body Water (Childhood)

60% to 65% of body weight

Total Body Water (Adults)

60% of body weight

Interstitial Fluid

Fluid around cells

Intravascular Fluid

Blood plasma (in capillaries)

Transcellular Fluid

Fluid in synovial, pericardial/peritoneal cavities

Intracellular Fluid

Fluid located inside of cells

Thirst Mechanism

Triggered by 2% water loss, regulated by the hypothalamus; osmoreceptor cells sense the internal environment and promote fluid intake when needed.

Antidiuretic Hormone (ADH)

Promotes the reabsorption of water into the blood from the kidney tubules.

Aldosterone

Controls the reabsorption of both sodium ions and water from the kidney tubules when there is a fluid deficit in the body.

Atrial Natriuretic Peptide (ANP)

Produced by myocardial cells in response to increased blood volume, leading to natriuresis (sodium excretion), which decreases blood volume and blood pressure.

Hydrostatic Pressure

Also known as blood pressure, is the 'push' force moving fluid out of the capillary.

Osmotic (Colloid/Oncotic) Pressure

The 'pull' force bringing fluid into the capillary; proteins and electrolytes contribute to this pressure.

Edema

Excessive accumulation of fluid within the interstitial (extracellular) spaces causing swelling or tissue enlargement.

Hyponatremia

Water intoxication resulting from compulsive water drinking, decreased urine formation, or Syndrome of Inappropriate ADH (SIADH)- dilution of extracellular sodium.

Diabetes Insipidus

Deficit of ADH leading to polyuria and thirst (due to dehydration).

Dehydration

Insufficient body fluid resulting from inadequate intake, excessive loss, or a combination of the two.

3rd spacing

Shift of fluid out of the blood into a body cavity or tissue where it is no longer available as circulating fluid, e.g. peritonitis, inflammation and infection of the peritoneal membranes, and burns.

Electrolytes

Dissolve into charged particles when placed in water and conduct electricity in solution also Control movement of water between fluid compartments

Sodium (Na+)

Primary cation in the extracellular fluid (ECF); controls ECF volume and is essential for conduction of nerve impulses.

Hyponatremia

Serum sodium concentration below 134 mEq/L from direct loss of sodium from the body or dilution by excess water.

Hypernatremia

Serum sodium concentration in the ECF > 145 mEq/L from ingestion of large amounts of sodium or loss of water faster than loss of sodium.

Potassium (K+)

Major intracellular cation; assists in the regulation of ICF volume, nerve conduction, and muscle contraction.

Hypokalemia

Serum level of potassium is < 3.5 mEq/L from excessive losses of K+ (e.g., diarrhea, diuresis) or decreased dietary intake.

Hyperkalemia

Serum level of potassium is > 5.5 mEq/L from renal failure, aldosterone deficit, or leakage of intracellular K+ into ECF.

Calcium (Ca2+)

Important extracellular cation; provides structural strength for bone and teeth, maintains nerve membrane stability, and is required for muscle contraction.

Hypocalcemia

Serum level of calcium is < 8 mEq/L from hypoparathyroidism, malabsorption, deficient serum albumin, or alkalosis.

Hypercalcemia

Serum calcium level is > 10.5 mEq/L from hyperparathyroidism, uncontrolled release of calcium ions, immobility, or increased intake of Ca2+.

Magnesium (Mg2+)

Important in many enzyme reactions as well as in protein and DNA synthesis.

Hypomagnesemia

Cause: malabsorption or malnutrition often due to chronic alcoholism, use of diuretics, diabetic ketoacidosis, hyperparathyroidimsm, and hyperaldosteronism.

Hypermagnese mia

Cause: occurs with renal failure

Phosphate

Bone and tooth mineralization, Metabolic processes involving ATP (cellular energy source), Integral part of the cell membrane

Chloride

Major extracellular anion that helps maintain acid/base balance.