Kidney and Acid/Base Levels

Vocabulary flashcards covering kidney function, pH regulation, blood buffer systems, and acid-base disorders.

Normal Blood Plasma pH

The physiological pH range of blood plasma, which is $7.35\text{--}7.45$.

Acidosis

A condition in which the body is too acidic due to an excess of $H^+$ ions and a blood pH below $7.35$.

Alkalosis

A condition in which the body is too basic due to an insufficiency of $H^+$ ions and a blood pH above $7.45$.

Renal Carbonic Anhydrase

An enzyme in kidney tubular cells that facilitates the reaction $H_2O + CO_2 \rightarrow H_2CO_3 \rightarrow H^+ + HCO_3^-$, allowing $H^+$ to be secreted into urine and $HCO_3^-$ to be reabsorbed into the blood.

 Renal $Na^+/H^+$ Antiporter

A cell membrane transport protein in kidney tubules that exchanges secreted $H^+$ ions for reabsorbed $Na^+$ ions.

Urinary Ammonia Buffering

The process where ammonia ($NH_3$) buffers secreted $H^+$ ions in the urine to form ammonium ($NH_4^+$) ions, helping regulate urinary acidity.

Carbonic Acid-Bicarbonate Buffer System

A key buffer system consisting of carbonic acid ($H_2CO_3$), a weak acid, and bicarbonate ($HCO_3^-$), a weak base, operating via $H_2CO_3 \rightleftharpoons HCO_3^- + H^+$.

Protein Buffer System

An intracellular and extracellular buffer system in which amino acids act as acids by releasing $H^+$ in alkaline media or as bases by absorbing $H^+$ in acidic media.

Hemoglobin Buffer System

An intracellular buffer system inside red blood cells where hemoglobin binds free $H^+$ ions ($H^+ + Hb \rightarrow HHb$) produced during $CO_2$ transport.

Chloride Shift

The exchange process in red blood cells where bicarbonate ($HCO_3^-$) moves out of the cell into plasma while a chloride ion ($Cl^-$) moves in.

Phosphate Buffer System

An intracellular buffer system operating via the reversible reaction $H_2PO_4^- \rightleftharpoons H^+ + HPO_4^{2-}$.

Respiratory Acidosis

An acid-base disorder caused by hypoventilation, leading to $CO_2$ retention ($P_{CO_2} > 40\,mmHg$), high $H^+$ concentration, and low blood pH.

Respiratory Alkalosis

An acid-base disorder caused by hyperventilation, leading to excessive loss of $CO_2$ ($P_{CO_2} < 40\,mmHg$), low $H^+$ concentration, and high blood pH.

Metabolic Acidosis

An acid-base disorder caused by loss of $HCO_3^-$ ($< 24\,mEq/L$) or acid accumulation; common causes include kidney failure, diarrhea, diabetic ketoacidosis, and hyperkalemia.

Metabolic Alkalosis

An acid-base disorder characterized by elevated $HCO_3^-$ ($> 24\,mEq/L$) and low $H^+$ levels; common causes include vomiting, excess antacids, and hypokalemia.

Respiratory Compensation

A mechanism where hyperventilation reduces blood $CO_2$ levels, thereby lowering $H^+$ concentrations to compensate for metabolic acidosis.

Hyperkalemia and Acid-Base Balance

Elevated potassium levels in the body that induce metabolic acidosis due to cellular $H^+/K^+$ ion exchange.

Hypokalemia and Acid-Base Balance

Low potassium levels in the body that induce metabolic alkalosis due to cellular $H^+/K^+$ ion exchange.

Analysis of Simple Acid-Base Disorders

A systematic diagnostic pathway using arterial blood sample pH, $HCO_3^-$ levels, and $P_{CO_2}$ levels to identify primary acid-base disturbances and compensatory responses.