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UNIT 7: CHAPTER 27
WATER, ELECTROLYTE AND ACID-BASE BALANCE
Identify the major fluid compartments of the body and their subdivisions.
Water accounts for at least half of the total body weight of the human body.
The percentage of water varies with development stage, gender, and body composition, for
example, men have, on average, a lower percentage of adipose tissue than women and a
greater percentage of a man’s body weight is due t water than it is for women. Adipose
tissue has a relatively low water content.
o The total amount of water in the body is separated into 2 major categories called
fluid compartments: (1) the intracellular fluid compartment and (2) the extracellular
fluid compartment.
o The intracellular fluid compartment consists of all the fluid inside the cells of the
body. This fluid is part of the cytoplasm of the cell.
o If account for the majority of water in the body, about 70%. This equals
approximately 40% of the body’s total weight.
o The extracellular fluid compartment accounts for about 30% of the water in the
body, which is about 20% of our total body weight.
o This fluid consists of fluid outside the cells of the body. And it is divided into multiple
sub-compartments, including;
1. interstitial fluid between cells,
2. plasma of the blood,
3. lymph within lymphatic vessels,
4. cerebrospinal fluid of the brain and spinal cord, and
5. synovial fluid within synovial joints.
o Interstitial fluid is the fluid found surrounding the cells of the body and filling the
extracellular spaces.
o Plasma is the liquid portion of blood inside all blood vessels of the body.
o Each fluid compartment and sub-compartment is composed of water, ions called
electrolytes and other solutes.
Discuss the causes of edema.
o Osmosis is the diffusion of water toward a solution with a higher solute
concentration.
o Let us look at an inflammatory response to an infection- this cause the permeability
of the capillary wall to increase- which allows proteins to exit the plasma and enter
the interstitial fluid- water will then move by osmosis- out of the plasma- and into
the interstitial fluid- which results in swelling or edema.
Explain how body water content is maintained.
Our body regulates its water content so that the total volume remains constant.
o The volume of water entering the body equals the volume exiting the body each day.
o Changes in the total water volume alter several factors in the body, such as; (1) the
solute concentration of body fluids, (2) blood pressure and (3) interstitial fluid
pressure.
UNIT 7: CHAPTER 27
WATER, ELECTROLYTE AND ACID-BASE BALANCE
Identify the major fluid compartments of the body and their subdivisions.
Water accounts for at least half of the total body weight of the human body.
The percentage of water varies with development stage, gender, and body composition, for
example, men have, on average, a lower percentage of adipose tissue than women and a
greater percentage of a man’s body weight is due t water than it is for women. Adipose
tissue has a relatively low water content.
o The total amount of water in the body is separated into 2 major categories called
fluid compartments: (1) the intracellular fluid compartment and (2) the extracellular
fluid compartment.
o The intracellular fluid compartment consists of all the fluid inside the cells of the
body. This fluid is part of the cytoplasm of the cell.
o If account for the majority of water in the body, about 70%. This equals
approximately 40% of the body’s total weight.
o The extracellular fluid compartment accounts for about 30% of the water in the
body, which is about 20% of our total body weight.
o This fluid consists of fluid outside the cells of the body. And it is divided into multiple
sub-compartments, including;
1. interstitial fluid between cells,
2. plasma of the blood,
3. lymph within lymphatic vessels,
4. cerebrospinal fluid of the brain and spinal cord, and
5. synovial fluid within synovial joints.
o Interstitial fluid is the fluid found surrounding the cells of the body and filling the
extracellular spaces.
o Plasma is the liquid portion of blood inside all blood vessels of the body.
o Each fluid compartment and sub-compartment is composed of water, ions called
electrolytes and other solutes.
Discuss the causes of edema.
o Osmosis is the diffusion of water toward a solution with a higher solute
concentration.
o Let us look at an inflammatory response to an infection- this cause the permeability
of the capillary wall to increase- which allows proteins to exit the plasma and enter
the interstitial fluid- water will then move by osmosis- out of the plasma- and into
the interstitial fluid- which results in swelling or edema.
Explain how body water content is maintained.
Our body regulates its water content so that the total volume remains constant.
o The volume of water entering the body equals the volume exiting the body each day.
o Changes in the total water volume alter several factors in the body, such as; (1) the
solute concentration of body fluids, (2) blood pressure and (3) interstitial fluid
pressure.
