Download MBBS Physiology Presentations 2 Renal Body Fluids Lecture Notes

Download MBBS (Bachelor of Medicine, Bachelor of Surgery) 1st Year, 2nd Year, 3rd Year and Final year Physiology 2 Renal Body Fluids PPT-Powerpoint Presentations and lecture notes

Body fluid compartments

Learning Objectives

To learn:

Composition of body fluid compartments.

Differences of various body fluid compartments.

Molarity, Equivalence,Osmolarity-Osmolality, Osmotic

pressure and Tonicity of substances

Effect of dehydration and overhydration on body fluids
Why is this knowledge important?

To understand various changes in body fluid

compartments, we should understand normal

configuration of body fluids.

Total Body Water (TBW)

Water is 60% by body weight

(42 L in an adult of 70 kg - a major part of body).

Water content varies in different body organs & tissues,
Distribution of TBW in various fluid compartments

Total Body Water (TBW) Volume

(60% bw)

________________________________________________________________

Intracellular Fluid Compartment

Extracellular Fluid Compartment

(40%)

(20%)

_______________________________________

Extra Vascular Comp

Intra Vascular Comp

(15%)

(Plasma )

(05%)

Electrolytes distribution in body fluid compartments

Intracel ular fluid comp.mEq/L

Extracel ular fluid comp.mEq/L

Major Cation Major Anions

Major Anions

K+

HPO4- -

Major Cation

Proteins -

Cl-

Na+

HCO3-
A set `Terminology' is required to understand

change of volume &/or ionic conc of various

body fluid compartments.

Molarity

Definition

Example
Equivalence

Osmolarity

Osmolarity is total no. of osmotically active solute particles (the

particles which attract water to it) per 1 L of solvent - Osm/L.

Example-
Osmolarity and Osmolality?

Osmolarity is total no. of osmotically active solute particles per

1 L of solvent - Osm/L

Osmolality is total no. of osmotically active solute particles per 1

Kg of solvent - Osm/Kg

Osmosis

Tendency of water to move passively, across a

semi-permeable membrane, separating two fluids

of different osmolarity is referred to as `Osmosis'.
Osmotic Pressure

Osmotic pressure is the pressure, applied to stop the flow of

solvent molecules from low osmolarity to a compartment of high

osmolarity, separated through a semi-permeable membrane.

Normal osmolality of the ECF and ICF

Averages 280-300 mOsm/L
Osmolality of ICF

Pressures causing water moves freely between

various body fluid compartments

Cell

Cp

memb

mem

b
Tonicity

Tonicity of a solution defines cell volume change that occurs, if the cell

is placed in that solution.

Significant points of the Lecture
Importance of the knowledge about Body Fluid Compartment ?

Water distribution in different compartment-

Ionic difference of different body fluid compartments-Major cation and anions-

Difference of Molarity, Equivalence, Osmolarity and Osmolality, Tonicity-
Next Lecture

Basic principles for analysis of fluid shifts between

ICF & ECF

All exchanges of water and solutes with

the external environment occur through

the extracellular fluid (ECF)

e.g. intake or loss via the

Gastrointestinal tract

Intravenous route.
Basic principles for analysis of fluid shifts between

ICF & ECF

Hyposmotic dehydration/overhydration will result in cell volume

and net Osmolarity

Hyperosmotic dehydration/overhydration will result in cell volume

and net Osmolarity

Clinical implications

Water loss from body (ECF) -

Dehydration (volume contraction)

Excess water gain to the body (ECF) -

Overhydration (volume expansion)
Signs and symptoms of `dehydration' and

`overhydration'

Dehydration (volume contraction)

Three types:

-Isosmotic dehydration

-Hyperosmotic dehydration,

-Hyposmotic dehydration

Overhydration (volume expansion)

Three types:

-Isosmotic overhydration

-Hyperosmotic overhydration

-Hyposmotic overhydration
Thank you