Disorders of potassium

Timothy J Schaefer1, Robert W Wolford

  • 1Section of Emergency Medicine, Department of Surgery, University of Illinois College of Medicine at Peoria, Peoria, IL 61605, USA. tjschaefer@pol.net

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Antihypertensive Drugs: Potassium-Sparing Diuretics01:28

Antihypertensive Drugs: Potassium-Sparing Diuretics

Liddle syndrome is a genetically inherited form of hypertension characterized by the overactivity of epithelial sodium channels in the nephron, the functional unit of the kidney. This heightened activity leads to increased sodium reabsorption and excessive excretion of potassium. To counteract this, potassium-sparing diuretics such as amiloride are used. They function by blocking these sodium channels, thereby reducing the influx of sodium into the epithelial cells and minimizing the loss of...
Roles of Electrolytes: Sodium and Potassium01:24

Roles of Electrolytes: Sodium and Potassium

Sodium plays a crucial role in maintaining fluid and electrolyte balance and overall bodily homeostasis. Sodium balance is primarily regulated by kidney function, which adjusts sodium elimination to match dietary intake and maintain proper electrolyte levels. Sodium is the most abundant cation in the extracellular fluid (ECF) and is found in salts such as sodium chloride (NaCl) and sodium bicarbonate (NaHCO3). Although cellular plasma membranes are relatively impermeable to sodium, its role in...
Regulation of Sodium and Potassium01:26

Regulation of Sodium and Potassium

The regulation of sodium and potassium ion concentrations in the human body is a complex process governed primarily by hormones such as aldosterone, antidiuretic hormone (ADH), and atrial natriuretic peptide (ANP).
Sodium Regulation
Sodium ions make up approximately 90% of extracellular cations, with a normal blood plasma concentration of 136–148 mEq/L. A decrease in blood volume and pressure triggers the release of renin from granular cells in the juxtaglomerular complex (JGC), primarily in...
Disorder of Water Balance01:29

Disorder of Water Balance

Water balance disorders are medical conditions that occur when there is a deviation from the body's water volume or osmolarity, disrupting normal homeostasis and leading todehydration, hypotonic hydration, hyperhydration, edema, or water intoxication.
Dehydration
Dehydration occurs when the body loses fluids (particularly water).
Causes:
The major causes of dehydration include excessive sweating, fever, vomiting, diarrhea, and diuresis.
Signs and Symptoms:
Symptoms primarily include intense...
Antiarrhythmic Drugs: Class III Agents as Potassium Channel Blockers01:12

Antiarrhythmic Drugs: Class III Agents as Potassium Channel Blockers

Class III antiarrhythmic drugs are a group of medications that can prolong action potentials in the heart. They achieve this by blocking potassium channels or enhancing inward currents from sodium channels. However, these drugs have a unique property of "reverse use-dependence," which is most pronounced at slower heart rates and can lead to torsades de pointes—a specific type of arrhythmia. However, it is essential to note that excessive QT interval prolongation—a measure of the heart's...
Disorders of Acid-Base Balance01:29

Disorders of Acid-Base Balance

The human body maintains a precise pH range of arterial blood between 7.35 and 7.45. Deviations result in either acidosis (pH < 7.35) or alkalosis (pH > 7.45). These conditions are further classified as respiratory or metabolic disorders based on their underlying cause.
Respiratory Acidosis and Alkalosis
Respiratory acidosis occurs due to an increase in the partial pressure of carbon dioxide PCO2 in the blood. It often arises from shallow breathing or impaired gas exchange caused by...