Acid-Base Balance and Fluid Compartments

Flashcards covering the fundamentals of pH, acid-base chemistry, respiratory and metabolic disorders, and body fluid compartment dynamics based on the lecture transcript.

Hydrogen ion concentration symbol

Indicated by putting brackets around the ion: $[H^+]$.

pH scale definition

The negative log of the hydrogen ion concentration, often called the "power of hydrogen" scale.

Acidic end

The end of the pH scale characterized by the highest hydrogen ion concentration ($0$ to $<7$).

Alkaline (Basic) end

The end of the pH scale characterized by a lower concentration of hydrogen ions ($>7$ to $14$).

Normal blood pH

The range between $7.35$ and $7.45$ in the human body.

Critical blood pH threshold

A level such as $7.2$ where a patient is at high risk of being lost or "coding."

Neutral pH

A pH of $7$, which is the value assigned to pure water.

Buffer system

A chemical reaction that resists a change in pH by taking acids and bases out of circulation or putting them back in to maintain balance.

Carbonic acid-bicarbonate equation

The primary buffer system in the body: $CO_2 + H_2O \rightleftharpoons H_2CO_3 \rightleftharpoons H^+ + HCO_3^-$.

Respiratory end

The portion of the buffer equation involving $CO_2$, controlled by the respiratory system.

Metabolic (Renal) end

The portion of the buffer equation involving $H^+$ and $HCO_3^-$, controlled by the urinary/renal system.

Acidosis

A condition in the blood where the pH is lower than $7.35$.

Alkalosis

A condition in the blood where the pH is above $7.45$.

Arterial Blood Gas (ABG)

A diagnostic blood test used to determine pH and identify respiratory or metabolic acid-base disorders.

Respiratory acidosis

An acid-base disorder caused by hypoventilation or conditions like COPD where the body retains too much $CO_2$.

Respiratory alkalosis

An acid-base disorder caused by hyperventilation, anxiety, or hypoxia, resulting in blowing off too much $CO_2$.

Metabolic acidosis

An acid-base disorder caused by conditions like diabetic ketoacidosis ($DKA$), renal failure, shock, or aspirin overdose.

Intracellular fluid (ICF) space

The fluid compartment inside the cells which contains the majority of the body's water.

Extracellular fluid (ECF) space

The fluid compartment outside of cells, subdivided into interstitial fluid and plasma.

Interstitial fluid

The fluid space that surrounds the cells.

Plasma space

The fluid space inside the circulatory system, typically comprising about $5$ liters.

Osmosis (Fluid movement definition)

The movement of water following particles into the space that is most concentrated.

Dehydration sequence

Fluid is first lost from the plasma, then pulled from interstitial fluid, and finally extracted from the intracellular fluid.

Antidiuretic hormone (ADH)

A hormone secreted in response to increased plasma osmolarity that adds water canals to collecting ducts to hang on to water.

Potassium ($K^+$)

The main cation found within the intracellular fluid space.

Sodium ($Na^+$)

The main cation found within the extracellular fluid space.

Aldosterone

A hormone that causes the kidneys to hang on to sodium ($Na^+$) and get rid of potassium ($K^+$).

Atrial natriuretic peptide (ANP)

A sodium-wasting hormone that causes the kidneys to get rid of water to lower blood volume.

Edema

The presence of too much water in the interstitial spaces, often caused by high blood pressure, low albumin, or blocked lymphatic systems.