Fluid, Electrolyte, and Acid-Base Homeostasis Overview

These flashcards cover key terms and concepts related to fluid, electrolyte, and acid-base homeostasis, including their definitions and physiological significance.

Fluid balance

Study of maintaining appropriate volume and concentration of body’s intracellular and extracellular fluids, largely focusing on water balance.

Electrolytes

Substances that dissociate into ions when placed in water and conduct electricity in a solution.

Acid

A chemical that dissociates in water to release a hydrogen ion (H+).

Base

A chemical that accepts a hydrogen ion in a solution, typically resulting in a salt and a molecule of water.

pH scale

Used to measure hydrogen ion concentration of a solution; a scale where pH less than 7 is acidic, greater than 7 is basic, and 7 is neutral.

Total body water

Reference volume indicating that about 60% of total body weight is composed of water, varying based on gender, body mass, age, and adipose tissue.

Intracellular fluid (ICF)

Fluid found within trillions of cells, accounting for about 60% of the body's fluids.

Extracellular fluid (ECF)

Fluid found outside cells, includes blood plasma and interstitial fluid.

Osmotic pressure

Pressure that determines the movement of water between compartments; it can be isotonic, hypotonic, or hypertonic.

Hormonal regulation of fluid balance

Mechanisms by which hormones like ADH, angiotensin-II, aldosterone, and ANP ensure balanced water input and output.

Sodium ions (Na+)

Most abundant extracellular cation, critical for cell depolarization and maintaining fluid balance.

Potassium ions (K+)

Most abundant intracellular cation, crucial for repolarization phases of action potentials.

Calcium ions (Ca2+)

Required for muscle contraction, blood clotting, and neuronal synaptic transmission.

Magnesium ions (Mg2+)

Ions critical in cellular processes, mainly found in bone and cytosol.

Acidosis

A condition characterized by a body fluid pH of less than 7.35, causing neurons to become less excitable.

Alkalosis

A condition defined by a body fluid pH greater than 7.45, leading to increased excitability of neurons.