The document discusses the composition and significance of body fluids, highlighting that over two-thirds of the body is made up of fluids. It details the water content in various organs and outlines the roles of body water in homeostasis, transport mechanisms, metabolic reactions, tissue texture, and temperature regulation. The total body water is specified at 40 liters, with distinctions between extracellular and intracellular fluid volumes.

1. Dr. Maya Chanderia
Dept. of Physiology

2.  Body is formed by solids and fluids.
 Fluid part – more than 2/3rd of the whole
body.
Individuals Body water (% of body
weight)
Infants 75
Adult males 60
Adult females 50
Elderly males 45
Elderly females 50

3. Organs Water content (%)
Adipose tissue 10
Blood 83
Bone 22
Brain 75
Heart 80
Intestine 75
Kidneys 83
Liver 68
Lungs 79
Skeletal muscles 75
Skin 70
Spleen 76

4.  1. In Homeostasis
◦ Body cells survive in the fluid medium called
internal environment or milieu interieur.
◦ Internal environment contains substances such as
glucose, amino acids, lipids, vitamins, ions, oxygen,
etc. which are essential for growth and functioning
of the cell.
◦

5.  2. In Transport mechanism
◦ Body water forms the transport medium by which
nutrients and other essential substances enter the
cells; and unwanted substances come out of the
cells.
◦ Water forms an important medium by which various
enzymes, hormones, vitamins, electrolytes and
other substances are carried from one part to
another part of the body.

6.  3. IN METABOLIC REACTIONS
◦ Water inside the cells forms the medium for various
metabolic reactions, which are necessary for growth
and functional activities of the cells.
 4. IN TEXTURE OF TISSUES
◦ Water inside the cells is necessary for characteristic
form and texture of various tissues.
 5. IN TEMPERATURE REGULATION
◦ Water plays a vital role in the maintenance of
normal body temperature.

7. Total water in the
body = 40 L
ECF – Vol 18 L &
45% of total body
water
Interstitial fluid &
lymph (20%)
Plasma (7.5%)
Other Fluids
(17.5%)
ICF – Vol 22 L &
55% of total body
water

8. Body fluids
Solids
Organic
Glucose, amino
acids & other
proteins
Fatty acids &
other lipids
Hormones &
enzymes
Inorganic
Na, K, Ca,
Mg, Cl,
Bicarbonate
, Phosphate
& Sulfate
Water

9. THANK YOU