Fluids and Electrolytes

100 vocabulary flashcards covering fluid dynamics, electrolyte ranges, and hormonal regulation based on the lecture notes.

Intracellular fluid (ICF)

Fluid located inside the cells, accounting for approximately two-thirds of the total body fluid weight.

Extracellular fluid (ECF)

Fluid located outside of the cells, accounting for one-third of the total body fluid and subdivided into intravascular and interstitial compartments.

Interstitial fluid

The portion of extracellular fluid found in the spaces between cells, outside of the vasculature.

Intravascular fluid

The portion of extracellular fluid found within the blood vessels, primarily consisting of blood plasma.

Homeostasis

The maintenance of a stable internal environment, including the delicate balance of fluid and electrolytes in the body.

Hydrostatic pressure

The 'pusher' pressure exerted by a stationary liquid against the walls of its compartment.

Oncotic pressure

Also known as colloid osmotic pressure, it is the 'puller' pressure exerted by proteins like albumin to retain water within the vasculature.

Colloid

A nondiffusable substance or solute, such as a protein, suspended in a solution; albumin is the primary example in blood plasma.

Albumin

The major protein in blood plasma responsible for maintaining oncotic pressure and facilitating fluid retention.

Starling's Law

The principle stating that equilibrium exists when the amount of fluid leaving circulation equals the amount of fluid returning.

Filtration

The process occurring at the arterial end of the capillary bed where fluid moves out of the vasculature into the tissue space.

Reabsorption

The process occurring at the venous end of the capillary bed where fluid is drawn back into the vasculature.

Lymphatic system

The system that acts like a 'shop vac' to clean up excess filtered fluid and escaped proteins, eventually draining them back into circulation.

Edema

The abnormal retention or accumulation of fluid in the interstitial spaces.

Pulmonary edema

A condition where fluid spills into the pulmonary interstitial space and alveoli, impairing gas exchange.

Fick's equation

A principle stating that increasing membrane thickness (due to excess fluid) decreases the rate of gas diffusion.

Sodium ($Na^+$)

The most abundant extracellular cation and the primary electrolyte responsible for promoting water retention and fluid balance.

Ideal body weight

The reference weight used to determine that approximately two-thirds of an adult's weight is water.

Insensible water loss

Water loss that occurs through natural evaporation from the skin and lungs which the body cannot control.

Sensible water loss

Perceivable water loss, such as urine, that can be somewhat altered by fluid intake.

Obligatory water loss

The total amount of water the body is required to lose, including all insensible losses.

Facultative water loss

The portion of urine output that can be increased or decreased based on the amount of excess fluid ingested.

Osmolality

The measure of dissolved particles (like sodium, BUN, and glucose) per kilogram of water, used to describe the condition of internal fluids.

Tonicity

A term used primarily to describe the concentration of external fluids (like IV bags) compared to blood plasma.

Isotonic solution

A solution with a solute concentration similar to blood plasma, such as $0.9\%$ NaCl, which does not cause fluid shifts.

Hypertonic solution

A solution with a higher solute concentration than blood, such as $3\%$ or $5\%$ saline, which pulls water from surrounding tissues.

Hypotonic solution

A solution with a lower solute concentration than blood, such as $0.45\%$ saline, which causes water to move into the cells.

Extracellular fluid volume deficit

A condition, also known as dehydration, where fluid is lost from both the interstitial and intravascular spaces.

Hyperosmolar fluid volume deficit

A type of dehydration where the loss of body water is greater than the loss of solutes like sodium.

Iso-osmolar volume deficit

A proportional or parallel loss of both body fluids and solutes, such as in cases of hemorrhage.

Urine Specific Gravity (USG)

A clinical measurement used to evaluate hydration; an increased value indicates more concentrated urine and dehydration.

Hemoconcentration

The false increase in blood values that occurs when there is insufficient fluid to dilute them.

Lactated Ringer's

A common volume replacement fluid containing a mixture of electrolytes that closely mimics blood plasma.

Hypervolemia

An excess of fluid in the interstitial and intravascular spaces, often caused by increased sodium or decreased protein.

Pitting edema

A form of edema where an indentation remains on the skin after pressure is applied and removed.

Pallor

A paleness of the skin that may be observed in edematous extremities.

Three D's of treatment

The clinical management strategy for fluid excess consisting of Diet (low sodium), Diuretics, and Digoxin.

Digoxin

A positive inotropic medication used to improve heart function and circulation in patients with cardiac insufficiency.

Third space fluid

Abnormal, nonfunctional, and physiologically useless fluid that accumulates in areas like the abdomen or pleural space.

Ascites

The abnormal accumulation of third space fluid within the abdominal cavity.

Water intoxication

Intracellular fluid volume excess caused by excessive water intake relative to solutes, leading to cell swelling.

Antidiuretic hormone (ADH)

Also known as vasopressin, this hormone promotes water retention by the kidneys to increase circulating volume.

Vasopressors

Medications used to increase blood pressure by causing vasoconstriction in patients suffering from shock.

Mannitol

An osmotic diuretic used in extreme cases to pull fluid from swollen cells into the extracellular space.

Electrolytes

Chemical compounds that dissociate in body fluids into ions and are capable of conducting an electrical current.

Cations

Positively charged electrolyte particles, such as sodium and potassium.

Anions

Negatively charged electrolyte particles, such as chloride and phosphorus.

Potassium ($K^+$)

The most abundant intracellular cation, critical for neuromuscular impulses and muscle contraction.

Magnesium ($Mg^{2+}$)

An intracellular cation that acts as a cofactor for enzymes, DNA synthesis, and protein synthesis.

Phosphorus ($PO_4^{3-}$)

The most abundant intracellular anion, vital for metabolism, muscle contraction, and urinary buffering.

BUN (Blood Urea Nitrogen)

The final product of protein metabolism excreted via the kidneys; it contributes to blood osmolality.

Glucose

A sugar found in the blood that acts as a dissolved particle contributing to the total osmolality.

Sodium potassium pump

A transport protein that uses energy to move ions against their concentration gradient to prevent cells from bursting.

Hypernatremia

A condition characterized by a sodium level above $145\,mEq/L$, often due to excessive salt intake or water loss.

Hyponatremia

A condition characterized by a sodium level below $135\,mEq/L$, the most common electrolyte imbalance.

Psychogenic polydipsia

A compulsive disorder characterized by excessive water drinking, which can lead to hyponatremia.

Chloride ($Cl^-$)

The most abundant extracellular anion, which plays a major role in acid-base balance and providing electroneutrality.

Cystic Fibrosis (CF)

A genetic disease characterized by abnormal chloride transport, leading to thick, dehydrated mucus secretions.

Hyperchloremia

An excess of chloride in the blood, often occurring alongside hypernatremia or metabolic acidosis.

Hypochloremia

A deficit of chloride, often caused by prolonged vomiting or GI suctioning.

Hypokalemia

Low potassium ($< 3.5\,mEq/L$), leading to 'low and slow' symptoms like lethargy and shallow respirations.

Hyperkalemia

High potassium ($> 5.0\,mEq/L$), a lethal condition that can cause dangerous cardiac arrhythmias and death.

Calcium ($Ca^{2+}$)

The most abundant mineral in the body ($99\%$ in bones/teeth), essential for clotting, nerve impulses, and muscle contraction.

Ionized calcium

The biologically active, free form of calcium that is not bound to proteins.

Hypercalcemia

An excess of calcium in the blood, which can be caused by vitamin D overdose or endocrine disorders.

Hypocalcemia

A deficit of calcium in the blood, often associated with renal failure or malabsorption.

Renin

An enzyme secreted by the kidneys that kickstarts a cascade to increase blood pressure when low pressure or low sodium is sensed.

Angiotensinogen

A precursor protein produced by the liver that circulates in the blood until acted upon by renin.

Angiotensin I

The intermediate product formed when renin acts on angiotensinogen.

ACE (Angiotensin Converting Enzyme)

An enzyme released from the lungs that converts Angiotensin I into the potent vasoconstrictor Angiotensin II.

Angiotensin II

A hormone that causes direct vasoconstriction and stimulates the adrenal glands to release aldosterone.

Aldosterone

A hormone that acts on the kidneys to promote the reabsorption of sodium and water, increasing blood pressure.

RAAS (Renin-Angiotensin-Aldosterone System)

The complex hormonal pathway involving the liver, kidneys, and lungs that regulates long-term blood pressure and fluid balance.

ANP (Atrial Natriuretic Peptide)

A hormone released by the atria of the heart when they are overstretched to promote the excretion of sodium and water.

BMP (Basic Metabolic Panel)

A lab test that measures glucose, BUN, creatinine, and basic electrolytes like sodium, potassium, and chloride.

CMP (Comprehensive Metabolic Panel)

An expanded lab test that includes all components of a BMP plus proteins and liver function indicators.

Nephrotoxic

A term describing substances, such as certain antibiotics, that are potentially damaging to the kidneys.

Vancomycin

A nephrotoxic antibiotic that requires clinicians to monitor 'peak and trough' levels to prevent kidney damage.

Severe dehydration BP indicator

A systolic blood pressure reading of less than $60\,mmHg$.

Adult water percentage

Approximately $66\%$ (two-thirds) of total body weight in a healthy adult.

Adipose tissue water content

Body fat or adipose tissue is essentially free of water.

Infant vs. Elderly water percentage

Infants have a higher percentage of body water, while the elderly have a lower percentage relative to weight.

Normal Sodium range

$135 \text{ to } 145\,mEq/L$.

Normal Potassium range

$3.5 \text{ to } 5.0\,mEq/L$.

Normal Chloride range

$95 \text{ to } 110\,mEq/L$.

Normal Phosphorus range

$2.7 \text{ to } 4.5\,mg/dL$.

Normal Magnesium range

$1.5 \text{ to } 2.5\,mEq/L$.

Normal Total Calcium range

$8.5 \text{ to } 10.5\,mg/dL$.

Anuria

The failure of the kidneys to produce or release urine, seen in fatal stages of dehydration.

Potassium-wasting diuretic

A medication like Lasix that promotes the excretion of potassium along with water.

B-complex vitamins

Vitamins essential for brain health that require magnesium for activation.

Vitamin D

A nutrient necessary for the effective absorption of both calcium and phosphorus.

Tums

A common over-the-counter medication that if taken in excess can lead to hypermagnesemia or hypercalcemia.

Vasoconstriction

The narrowing of blood vessels to increase blood pressure, a primary goal of the RAAS system.

Fluid flux

The movement of water between compartments, such as from the cell to the blood during vascular dehydration.

Daily Potassium requirement

The human body requires approximately $40 \text{ to } 60\,mEq$ of potassium per day.

GFR (Glomerular Filtration Rate)

The rate of blood filtration in the kidneys, which increases when hydrostatic pressure rises due to high sodium/water.

Bone Calcium percentage

Approximately $99\%$ of the body's total calcium is found in the bones and teeth.

Hyperosmolar state

A condition where the blood has a high concentration of solutes, typically pulling water out of the cells.

Airway clearance

A respiratory therapy goal for CF patients to remove thick mucus resulting from abnormal chloride transport.