Fluid & Electrolyte Balance

These flashcards cover key terms and definitions related to fluid and electrolyte balance, essential for understanding the body's homeostasis.

Fluid and Electrolyte Balance

The regulation of body fluid volume, osmolality, and composition, as well as the regulation of electrolytes by the processes of filtration, diffusion, osmosis, and selective excretion.

Intracellular fluid (ICF)

Fluid that is found inside the cells, constituting about 2/3 of the body’s water.

Extracellular fluid (ECF)

Fluid that is found outside the cells, including interstitial fluid, CSF, synovial fluid, and other bodily fluids.

Filtration

The movement of water through a cell or blood vessel due to hydrostatic pressure.

Diffusion

The tendency of molecules to move from a region of high concentration to one of lower concentration, as seen with gases, electrolytes, and other particles.

Osmosis

The movement of water across a semipermeable membrane toward an area of higher solute concentration.

Aldosterone

A hormone secreted by the adrenal cortex that prevents water and sodium loss when sodium levels are low in ECF.

Antidiuretic hormone (ADH)

A hormone released from the posterior pituitary gland in response to changes in blood osmolarity that regulates water retention.

Natriuretic peptide (NP)

A hormone secreted by the heart in response to increased blood pressure or blood volume that helps to lower blood pressure.

Dehydration

A condition where fluid intake or retention does not meet the body’s fluid needs, leading to a fluid volume deficit.

Fluid overload

A condition characterized by an excess of body fluid in the vascular space, potentially leading to heart failure and pulmonary edema.

Hypokalemia

A condition characterized by low potassium levels, which can occur due to excessive fluid loss or inadequate intake.

Hypervolemia

An excessive volume of fluid in the blood, often resulting from overhydration or failure to excrete fluids adequately.

Signs of Dehydration

Indicators include thirst, dry mucous membranes, decreased skin turgor, and changes in vital signs.

Laboratory Tests for Electrolyte Imbalance

Tests that include serum electrolyte concentrations, blood urea nitrogen (BUN), and serum osmolality to assess fluid and electrolyte status.

Renin-Angiotensin-Aldosterone System (RAAS)

A hormonal system that aids in regulating blood pressure and fluid balance.

Edema

Swelling caused by an excess of fluid in the body's tissues, often related to imbalances in fluid dynamics.

Thirst drive

The body's natural mechanism that regulates fluid intake based on hydration status.

Clinical example of Osmosis

Water moves from an area of lower solute concentration (dilute fluid) to an area of higher solute concentration.

Assessment of Fluid Volume

Includes taking daily weights, monitoring intake and output, and checking skin turgor and radial pulse.

Fluid replacement therapy

The process of replenishing lost fluids in the body, often through oral or intravenous methods.

Isotonic Solutions

Solutions that have the same tonicity as intracellular fluid, used for fluid and electrolyte replacement.

Hypotonic Solutions

Solutions with fewer solutes than intracellular fluid, which causes fluid to shift into cells.