Fluid and Electrolyte Imbalances Vocabulary

Flashcards covering fluid compartments, transport mechanisms, fluid balance alterations, and electrolyte imbalances based on the Chapter 2 lecture material.

Intracellular Fluid (ICF)

Fluid located inside the cells, which accounts for approximately two-thirds of total body water or $40\%$ of total body weight in an adult male.

Extracellular Fluid (ECF)

Fluid located outside the cells, which accounts for approximately one-third of total body water and includes intravascular fluid, interstitial fluid, cerebrospinal fluid, and transcellular fluids.

Osmoreceptors

Sensory receptors located in the hypothalamus that detect changes in plasma osmolality and promote the thirst mechanism.

Antidiuretic Hormone (ADH)

A hormone that promotes the reabsorption of water from kidney tubules back into the blood to conserve body water.

Aldosterone

A hormone that regulates fluid balance by determining the reabsorption of sodium ions and water in the kidneys.

Atrial Natriuretic Peptide (ANP)

A hormone released by cardiac muscle cells that regulates fluid, sodium, and potassium levels in the body.

Diffusion

The random movement of solute particles in all directions through a solution from an area of higher concentration to an area of lower concentration.

Active Transport

The movement of solutes across cell membranes against a concentration gradient, requiring metabolic energy expenditure (ATP).

Filtration

The transfer of water and solutes through a membrane from a region of higher pressure to a region of lower pressure.

Osmosis

The movement of water across a semipermeable membrane from a less concentrated solution to a more concentrated solution.

Hydrostatic Pressure

The pushing force exerted by a fluid against a vessel wall or membrane, such as blood pressure pushing fluid out of capillaries.

Osmotic Pressure

The pulling force exerted by solutes in a solution that attracts water across a semipermeable membrane.

Isotonic Solution

A solution in which the ratio of solutes to fluid is balanced with normal body fluids, resulting in no net movement of water into or out of cells.

Hypertonic Solution

A solution with a higher ratio of solutes to fluid than normal body fluids, causing water to shift out of cells via osmosis and leading to cell shrinkage.

Hypotonic Solution

A solution with a lower ratio of solutes to fluid than normal body fluids, causing water to shift into cells via osmosis and leading to cell swelling.

Edema

An excessive accumulation of fluid in the interstitial compartment that leads to swelling or enlargement of tissue.

Pitting Edema

A form of edema where excess interstitial fluid moves aside when finger pressure is applied, leaving a temporary depression or pit in the tissue upon removal.

Dependent Edema

A type of localized swelling in gravity-dependent areas of the body, such as the lower legs, ankles, and feet.

Dehydration

A body fluid deficit caused by inadequate intake, excessive fluid loss, or a combination of both, which is often monitored by reductions in body weight.

Third-Spacing

A condition in which fluid shifts out of the blood and becomes trapped in a body cavity or tissue space where it can no longer reenter the vascular compartment.

Hyponatremia

A serum sodium concentration below $135\,mEq/L$, which causes fluid to shift into cells and can result in cerebral edema, muscle cramps, and confusion.

Hypernatremia

A serum sodium concentration exceeding $145\,mEq/L$, which leads to cell shrinkage, agitation, dry mucous membranes, and elevated blood pressure.

Hypokalemia

A serum potassium level below $3.5\,mEq/L$, which impairs cardiac repolarization and can cause cardiac dysrhythmias, muscle weakness, and paresthesias.

Hyperkalemia

A serum potassium level exceeding $5\,mEq/L$, which impairs neuromuscular function and cardiac conduction, posing life-threatening risks of cardiac arrest and paralysis.

Hypocalcemia

A serum calcium level below $8.5\,mEq/L$, which increases the permeability and excitability of nerve membranes, leading to muscle twitching, carpopedal spasms, and tetany.

Hypercalcemia

A serum calcium level exceeding $10.2\,mEq/L$, which depresses neuromuscular activity, resulting in muscle weakness, lethargy, and decreased renal function.