ICU learning pathway | Renal Regulation of Body Fluid pH

Renal Regulation of Body Fluid pH
Session Overview
Description
This session deals with the regulation of extra and intracellular hydrogen ion concentration.

By the end of this session you will be able to:

• Define physiological buffers
• Describe the Henderson-Hasselbach equation
• Describe how the kidneys regulate plasma bicarbonate concentration
• Discuss the regulation of H+ secretion and the concepts of compensation and correction in various acid base disturbances

Before commencing this session you should complete:

• Blood Supply and Glomerular Filtration (001-0654)
• Tubular Transport and the Proximal Tubule (001-0655)
• Loop of Henle, Distal Tubule and Collecting Tubule (001-0656)
• Regulation of Body Fluid Volume and Sodium Reabsorption (001-0657)

A constant hydrogen ion concentration, usually described by the pH -log [H+], is important for normal metabolism.

The pH in health is kept within the range of 7.35-7.45 ([H+] of 45-35 nmol/L), although a wider range of 7.0-7.87 may be tolerated for short periods.

The regulation of pH is achieved through:

• The presence of physiological buffers
• Compensatory mechanisms

The kidneys play a central role in the physiological buffer system.