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09:41
Establishment of an Extracellular Acidic pH Culture System
Published on: November 19, 2017
What is the ultimate goal in acid-base regulation?
Selvakumar Balakrishnan1, Maya Gopalakrishnan, Murali Alagesan
1Department of Physiology, Jawaharlal Institute of Postgraduate Medical Education and Research, Pondicherry, India.
Advances in Physiology Education
|March 1, 2007
Summary
The body regulates acid-base balance to maintain intracellular fluid pH, not just arterial plasma pH. This ensures proper homeostasis and prevents severe consequences like respiratory depression and coma.
Area of Science:
- Physiology
- Biochemistry
Background:
- Acid-base physiology traditionally emphasizes maintaining arterial plasma pH.
- This view may overlook the critical role of intracellular pH regulation.
Purpose of the Study:
- To challenge the misconception that only arterial plasma pH is regulated.
- To highlight the importance of intracellular pH in acid-base homeostasis.
Main Methods:
- Analysis of a hypothetical case using the modified Henderson equation.
- Examination of physiological consequences of altered acid-base parameters.
Main Results:
- A scenario with normal arterial pH but potential intracellular acidosis was presented.
- Intracellular hypercapnia was identified as a risk associated with high PaCO2.
- Clinical manifestations like respiratory depression and coma were linked to deranged homeostasis.
Conclusions:
- Acid-base regulatory mechanisms aim to maintain steady-state intracellular fluid pH.
- Maintaining intracellular pH is crucial for overall physiological homeostasis.
Related Concept Videos
01:25Acid-Base Balance
The human body maintains a narrow pH range regulated through acid-base balance. This balance is crucial as changes in the hydrogen ion concentration can disrupt cell membrane stability, alter protein structures, and change enzyme activities. The normal pH of arterial blood is 7.4, venous blood and interstitial fluid is 7.35, and intracellular fluid averages 7.0.
When the pH of arterial blood rises above 7.45, it results in a condition called alkalosis. Conversely, a drop below 7.35 leads to...
When the pH of arterial blood rises above 7.45, it results in a condition called alkalosis. Conversely, a drop below 7.35 leads to...
01:18Respiratory Regulation of Acid-Base Balance
Respiratory compensation is a vital physiological process that stabilizes blood plasma pH by regulating the partial pressure of carbon dioxide (PCO2), a key determinant of pH levels. Most carbon dioxide in the blood dissolves and converts into carbonic acid (H2CO3). It dissociates into hydrogen ions (H+) and bicarbonate ions (HCO3⁻). There is also an inverse relationship between PCO2 and pH.
When carbon dioxide levels increase in the blood, more H+ and HCO3⁻ are produced, leading to a...
When carbon dioxide levels increase in the blood, more H+ and HCO3⁻ are produced, leading to a...
01:29Renal Regulation of Acid-Base Balance
Metabolic reactions in the body produce nonvolatile acids, such as sulfuric acid, which generate an acid load of approximately 1 mEq of H+ per kilogram of body weight daily. Excreting H+ in the urine is essential to balance this acid load.
In the kidneys, cells within the proximal convoluted tubules (PCT) and the collecting ducts secrete hydrogen ions (H+) into the tubular fluid. Specifically, in the PCT, Na+/H+ antiporters secrete H+ while reabsorbing Na+.
However, the intercalated cells in...
In the kidneys, cells within the proximal convoluted tubules (PCT) and the collecting ducts secrete hydrogen ions (H+) into the tubular fluid. Specifically, in the PCT, Na+/H+ antiporters secrete H+ while reabsorbing Na+.
However, the intercalated cells in...
01:31pH Homeostasis
Acid-base homeostasis is essential for maintaining normal physiological activities in humans. The pH of various body fluids is strictly regulated because it is critical for the optimal activity of enzymes involved in metabolic reactions. Enzymes are basically proteins, so, any significant change in pH can affect their structure and activity. In humans, pH is regulated using three primary mechanisms— chemical buffer systems, respiratory regulation, and renal regulation.
Respiratory Regulation of...
Respiratory Regulation of...
01:24Diagnosing Acidosis and Alkalosis
Diagnosing acid-base imbalances involves systematically analyzing arterial blood samples, focusing on three key measurements: pH, bicarbonate (HCO3−) concentration, and carbon dioxide partial pressure (PCO2). This analysis follows a four-step process that helps identify the imbalance's underlying cause and nature.
First, the pH level is assessed to determine whether the blood pH is normal (7.35–7.45), low (acidosis), or high (alkalosis).
Next, the PCO2 and HCO3− values are examined to...
First, the pH level is assessed to determine whether the blood pH is normal (7.35–7.45), low (acidosis), or high (alkalosis).
Next, the PCO2 and HCO3− values are examined to...
01:28Compensation Mechanisms
The human body employs intricate mechanisms to counteract changes in blood pH, preventing conditions like acidosis (pH < 7.35) and alkalosis (pH > 7.45). These compensatory responses aim to restore normal arterial blood pH by engaging respiratory or renal systems, depending on the source of the imbalance.
Respiratory Compensation
This mechanism addresses metabolic-induced pH imbalances by adjusting breathing rates. Respiratory compensation begins within minutes of detecting a pH...
Respiratory Compensation
This mechanism addresses metabolic-induced pH imbalances by adjusting breathing rates. Respiratory compensation begins within minutes of detecting a pH...