5
ACID-BASE BALANCE
C. ALBERS
I. Introduction . . . . . . . . . . . . 173
11. Basic Concepts of Physical Chemistry
. . . . . . 174
A. The Dissociation of Water and the Definition of pH
. . 174
B. Dissociation of Weak Acids . . . . . . . . 175
C. Carbonic Acid
. . . . . . . . . . 177
E. Effects of Ionic Strength and Temperature
. . . . 183
111. The Transport of COZ in the Blood . . . . . . . 188
A. The COz Combining Curve of the Blood
. . . . . 188
B. The pH of the Blood as Related to COz
196
IV. The Intracellular pH . . . . . . . . . . 203
References . . . . . . . . . . . . . 205
D. Buffer Action and Its Mathematical Description . . . 181
. . . . .
V. Controlling Mechanisms of the Acid-Base Balance . . . 204
I. INTRODUCTION
This chapter deals with the chemical reactions and the physiological
mechanisms affecting the concentration of hydrogen ions in the various
fluid compartments of the body. Since acids are substances capable of delivering hydrogen ions, the concentration of hydrogen ions- [H+] depends
primarily on the amount of the various acids present in the body fluids.
The most important of these is carbonic acid which is derived from
carbon dioxide (CO,), one of the major end products of metabolism.
Hence the equilibrium equations of carbonic acid and its reactions with
the so-called buffer substances form the chemical basis of CO, transport and acid-base balance. The concentration of CO, and the chemical
composition of the body fluids are therefore the principal factors governing acid-base balance. The former is controlled by ventilation, the latter
by the action of various excretory mechanisms.
In the term “acid-base balance,” acid stands for the sum of all anions
173
ACID-BASE BALANCE
C. ALBERS
I. Introduction . . . . . . . . . . . . 173
11. Basic Concepts of Physical Chemistry
. . . . . . 174
A. The Dissociation of Water and the Definition of pH
. . 174
B. Dissociation of Weak Acids . . . . . . . . 175
C. Carbonic Acid
. . . . . . . . . . 177
E. Effects of Ionic Strength and Temperature
. . . . 183
111. The Transport of COZ in the Blood . . . . . . . 188
A. The COz Combining Curve of the Blood
. . . . . 188
B. The pH of the Blood as Related to COz
196
IV. The Intracellular pH . . . . . . . . . . 203
References . . . . . . . . . . . . . 205
D. Buffer Action and Its Mathematical Description . . . 181
. . . . .
V. Controlling Mechanisms of the Acid-Base Balance . . . 204
I. INTRODUCTION
This chapter deals with the chemical reactions and the physiological
mechanisms affecting the concentration of hydrogen ions in the various
fluid compartments of the body. Since acids are substances capable of delivering hydrogen ions, the concentration of hydrogen ions- [H+] depends
primarily on the amount of the various acids present in the body fluids.
The most important of these is carbonic acid which is derived from
carbon dioxide (CO,), one of the major end products of metabolism.
Hence the equilibrium equations of carbonic acid and its reactions with
the so-called buffer substances form the chemical basis of CO, transport and acid-base balance. The concentration of CO, and the chemical
composition of the body fluids are therefore the principal factors governing acid-base balance. The former is controlled by ventilation, the latter
by the action of various excretory mechanisms.
In the term “acid-base balance,” acid stands for the sum of all anions
173