Cellular Adaptation, Tissue Injury, and Fluids & Electrolytes

Practice vocabulary flashcards covering key concepts from cellular adaptation, tissue injury, necrosis, fluid distribution, and electrolyte imbalances.

Atrophy

A decrease in cell size leading to a decrease in organ size.

Hypertrophy

An increase in cell size without cell division or mitosis, resulting in an enlarged organ.

Hyperplasia

An increase in the number of cells due to an increased rate of cell division, requiring cells capable of mitosis.

Hypoxic / Ischemic Injury

Cell injury occurring when cells receive inadequate oxygen, causing them to switch to anaerobic metabolism, lower pH, and accumulate lactic acid.

Ischemia

A condition characterized by reduced blood flow and reduced oxygen delivery to tissues.

Necrosis

Irreversible cell death caused by prolonged ischemia, characterized by swelling, cell bursting, and inflammation.

Dry Gangrene

A form of tissue necrosis where the tissue appears dry, wrinkled, and blackened.

Wet Gangrene

A form of tissue injury involving liquefaction, a foul odor, and rapid spread that can become systemic.

Gas Gangrene

A type of gangrene caused by Clostridium perfringens infection, characterized by gaseous bubbles in the tissue.

Total Body Water

The overall fluid content in the body, accounting for approximately $600\%$ of total body weight.

Intracellular Fluid (ICF)

Fluid located inside cells, constituting approximately $66\%$ of total body water.

Extracellular Fluid (ECF)

Fluid located outside cells, constituting approximately $33\%$ of total body water ($25\%$ interstitial fluid and $8\%$ blood plasma).

Hydrostatic Pressure

The water pushing pressure exerted within a fluid compartment.

Osmotic / Oncotic Pressure

The water pulling pressure exerted by solutes and proteins.

Isotonic IV Fluids

Intravenous solutions with equal concentration to plasma (e.g., $0.9\%$ Normal Saline, Lactated Ringer's, D5W) that leave cell size unchanged.

Hypotonic IV Fluids

Intravenous solutions with lower concentration than plasma (e.g., $0.45\%$ Normal Saline) that cause fluid to move out of the vascular space and into cells, causing cells to swell.

Hypertonic IV Fluids

Intravenous solutions with higher concentration than plasma (e.g., $3\%$ Saline, D5W + $0.9\%$ Saline) that cause fluid to move from cells into the vascular space, causing cells to shrink.

Isotonic Hypovolemia

A proportional loss of sodium and water caused by emesis, gastric drainage, diarrhea, burns, hemorrhage, or diaphoresis.

Third-Spacing

Abnormal accumulation of fluid in transcellular or interstitial spaces (e.g., ascites, edema, pleural effusion) where it is physiologically unavailable.

Hypernatremia

A high sodium level characterized by thirst, dry mucous membranes, oliguria, and neurological manifestations such as confusion, lethargy, seizures, and coma.

Hypokalemia

A low potassium level caused by GI loss, renal loss, inadequate intake, or alkalosis (as $H^+$ shifts out of cells to adjust pH, $K^+$ shifts into cells).

Hypocalcemia

A low calcium level (inversely related to phosphorus) characterized by increased cell membrane excitability, tremors, muscle spasms, seizures, dysrhythmias, hyperreflexia, and decreased bone density.

Trousseau's Sign

A carpal spasm induced by inflating a blood pressure cuff on the upper arm for $3\,\text{minutes}$, serving as a classic sign of hypocalcemia.

Chvostek's Sign

A clinical sign of hypocalcemia where tapping the facial nerve in front of the ear elicits facial muscle twitching of the nose, mouth, or eye.