The document discusses water and electrolyte balance in the human body. It explains that water moves between body fluid compartments via osmosis, flowing from areas of high water concentration to low. The concentration of solutes like electrolytes determines the direction of water movement. The body contains about 40 liters of water, with higher percentages in babies and men versus women. Fluid is divided between intracellular and extracellular compartments, with the intracellular space containing around two-thirds of total body water. Extracellular fluid further separates into interstitial fluid and blood plasma.

1. PHARM D 1STYEAR
MEDICINAL BIOCHEMISTRY
1.3
WATER, ELECTROLYTE
Dr Rina Das
Associate Professor
MM College of Pharmacy,
MM(DU), Mullana

2. Balance – a state of equilibrium –
substances are maintained in the
right amounts and in the right
place in the body

3. Water Balance
•Osmosis is the primary method of water movement
into and out of body fluid compartments.
•Osmosis is the net movement of water molecules
through a selectively permeable membrane from an
area of high water concentration to an area of lower
water concentration.

4. •The concentration of solutes determines
the direction of water movement.
•Most solutes in the body are electrolytes
– inorganic compounds which dissociate
into ions in solution.

5. •About 40 Liters (10.56 gallons) of
body water
•Babies – 75% water
•Men – 63 %
•Women – 52%

6. Fluid compartments
•Separated by selectively permeable
membranes
•Intracellular – 2/3 (63%) of total body water
•Extracellular – 1/3 (37%)
•Interstitial fluid – 80 % of extracellular water
•Blood plasma – 20 % of extracellular water

7. Composition of compartments
•Extracellular fluids:
• High in Na+, Cl-, Ca++, HCO3-
•Blood plasma has more protein than
interstitial fluid and lymph
•Intracellular fluids:
• High in K+, phosphate, Mg++, and more protein than plasma