unit/chapter 1
TRANSCRIPT
WATER • Most abundant
inorganic
compound
• Forms 60-70% of
body weight
• Closely associated
with electrolytes
• Present both inside
and outside of the
cells
• Two water compartments
–Intracellular water
–Extracellular water
• Extracellular water is
further subdivided into:
–Plasma
–Interstitial fluid
–Dense connective tissue
(bones, cartilages)
–Transcellular fluids
WATER
In lean adults, body fluids
constitute 55% of female and 60% of male total body
mass
Intracellularfluid (ICF) inside cells
• About 2/3 of body fluid
Extracellular fluid (ECF) outside cells
• Interstitial fluid between cell is 80% of ECF
• Plasma in blood is 20% of ECF
FUNCTIONS OF WATER
• Acts as a carrier of nutritive elements to tissues and remove waste materials from tissues.
• It provides the media in which chemical reactions of the body take place.
• The fluidity of blood is because of water
• It is a solvent for electrolytes and regulates the electrolytic balance of the body.
• Maintains the equilibrium of osmotic pressure extended by the solutes dissolved in water.
water
• Is a
• Polar molecule
Water
• Neutral charge
water
• Essential in maintaining acid base balance
WATER BALANCE
• Maintain by a body when
water gained by the body is
equal to the water lost from
the body.
Maintaining Water
Balance
• Is necessary for normal reactions within the cells
• Is maintained by adaptation to changes in water intake and water loss
Fluid homoestasis
• Amount consumed = Amount excretedWater balance
- The only physiological control is through variations in urine
volume. - urine volume regulated by
hormones
DEHYDRATION
• Occurs when fluid loss from the body is abnormally high.
• Electrolyte changes
• Corrected by electrolytes and water
• Excessive perspiration in hot weather, severe diarrhea, fever, vomiting, severe burns, and in uncontrolled diabetes with frequent urination.
ELECTROLYTES
• Substances that conduct an electrical
current in solution.
• Acids, base and salts are soluble in water
are called ELECTROLYTES.
COMMON ELECTROLYTES
• SODIUM CHLORIDE NaCl Na+ + Cl-
• POTASSIUM CHLORIDE KCl K+ + Cl-
• CALCIUM CHLORIDE CaCl2 Ca+2 + 2Cl-
• MAGNESIUM CHLORIDE MgCl2 Mg+2 + 2Cl-
• CALCIUM CARBONATE CaCO3 Ca+2 + CO3-2
• CALCIUM PHOSPHATE Ca3(PO4)2 3Ca+2 + 2PO4-3
• SODIUM SULPHATE Na2SO4 2Na+ + SO4-2
PROPERTIES OF WATER
• HIGH HEAT CAPACITY
–Absorbs and releases large amounts of
heat
–Prevents the sudden changes in body
temperature
• Intense sun exposure
• Chilling winter winds
• Internal events such as vigorous
muscle activity
PROPERTIES OF WATER• POLARITY / SOLVENT PROPERTIES
–Nutrients, respiratory gases (O2 & CO2) and
waste are dissolved in water – act as transport
and exchange medium in the body.
–Substances ---- Blood plasma exchanged
between blood and tissue cells------} Interstitial
fluid
PROPERTIES OF WATER• CHEMICAL REACTIVITY
–Important reactant in a chemical reactions
–Examples
• To digest foods
• Breakdown biological molecules
When bones meet at a joint, they need a fluid between the bones to prevent scraping against each other.That fluid is called a synovial fluid, which is made mainly of water.Many internal organs have fluid around them to keep them protected. Examples:
Brain: Cerebro-spinal fluidLungs: Pleural FluidEyes: Mix of fluids.
During pregnancy the fetus is surrounded by watery amniotic fluid
Water As A Lubricant
Synovial
Fluid
PROPERTIES OF WATER• CUSHIONING
–Serves a protective function
–Forms:
• Cerebrospinal fluid (CSF ) – cushion around
the brain
• Amniotic fluid – surrounds a developing
fetus and protecting as well
–Water as lubricant – prevents friction
–Synovial fluid – within joint cavities prevents
friction as bones move