- Body fluids.
- Cell physiology.
- Intercellular connection.
- Transport across the cell membrane.
Body fluids :
Example – 70 kg of man.
Body water = 60% of 70kg = 42L.
ICF = 40% of 70kg = 28L( 2/3 of 42L = 28L).
ECF = 20% of 70kg = 14L(1/3 of 42L = 14L).
Plasma = 5% of 70kg = 3.5L(1/4 of 14L = 3.5L).
Inertial fluid = 15% of 70kg = 10.5L or ¾ of ECE = 10.5L.
Diarrhea, vomiting, burn -> ECF loss.
Ionic composition of ECF and ICE:-
Total no. of ions on both side are equal.
Therefore, the osmolality and osmotic pressure are equal on both side.
Major cation in ECF:- Na+>Ca²+.
Major Anion in ECF:- Cl->HCO³-.
Major ion in ECF:- Na+.
Intracellular osmolality is mainly due to – K+.
Extracellular osmolality is mainly due to – Na+.
Major cation in ICF :- K+>Mg²+.
Major anion in ICF :- Po4³->Proteins.
Major ion in ICF :- K+.
Q). Ratio of ECE : ICF Ca²+ = 12000:1.
Q). Normal Na+ level in plasma = 135 – 145 mEq/to (mosm./L).
Normal K+ level in plasma = 3.5-5.0 mEq/ L or (mosm./L).
Normal Cl- level in plasma = 108-110 mEq/L or (mosm./L).
Factors shifting K+ from:
A) ECF to ICF = ↓ECE K+ level -Hypokalemia.
B) ICF to ECF = ↑ ECF K+ level -Hyperkalemia.
ECF→ ICF (K+) All bald person In Home.
4) Hypo-osmolality ( ↓ ECF osmolality).
5) B₂ receptor stimulation.
1) Insulin can be given to treat hyperkalemia.
2) In DM – Insulin is given → monitor plasma K+ level.
3) Excess of aldosterone lead CONN Syndrome – Hypokalemia.
ICF K+ → ECF (HYPER)
1)Insulin↓ (Diabetes Mellitus).
2) ↓ Aldosterone (Aldosterone deficiency disease).
3) Acidosis (Hyperkalemia).
4) Hyper osmolality (↑ECF osmolality).
5) B₂ blocker.
6) Cell injury/cell lysis.
7) Severe exercise.
Major reservoir of;
a) Na+ → ECF (65% of the body Na+ is present in ECF).
b) K+ → Skeletal muscle (3/4 of body K+ is present in skeletal m.).
C) Ca²+, Po4³-, Mg²+ → Bone.
D) Ee²+ – Hemoglobin.
Ee³+ – Ernestine (liver).
Osmolarity and osmolality:
Osmolarity = No. of osmoles/ Volume of Solution (L).
Osmolality = No. of osmoles / Mass of Solvents (kg).
Osmolality is better to express the concentration of electrolytes/solutes because it is independent of temperature because mass does not change C temperature where as volume changes with temperature.
Therefore the value of osmolality do not change with temperature. Whereas the value of osmolarity vary C temperature.
Normal plasma osmolality = 280-295mosm/kg of water.
= 280-295 mosm /L. of water.
Plasma osmolality is mainly due to Na+.
Isotonic fluid –
fluid having osmolality equal to that of plasma osmolality.
Eg.- 0.9% Nacl.
fluid having less osmolality than plasma osmolality.
Eg.- <0.9% Nacl.
< 10% mannitol.
fluid osmolality > Plasma osmolality.
Eg- >0.9% Nacl.
|HYPERTONIC FLUID||ISOTONIC FLUID||HYPOTONIC FLUID|
|Fluid osmolality > plasma osmolality.||Fluid of osmolality= plasma.||FO<PO.|
|Cell shrinks.||No change||Cell swells|
-ne log [H+]
PH scale :-
Where >6 is acidic, 7 is neutral and 8< is alkaline.
PH = 7 = neutral water.
PH < 7 = Acidic water.
PH > 7 = Alkaline water.
If Ph changes by 1, [H+] changes by 10 times.
Ph 7→6, ↑ [H+] by 10 times.
Ph 7→2, ↑ [H+] by 10s.
Ph of some body fluid;
1)Plasma – 7.40 (7.35 – 7.45) Normal PH of plasma is alkaline.
2) Venous Plasma -7.36
3) CSF – 7.30 – 7.33
4) Gastric Juice – 0.8 – 3.0 [most acidic fluid in the body ors least Ph].
5) Gall bladder bile – 7.40
6) Hepatic duct bile -7.8 – 8.6.
7) Pancreatic Juice – 7.8- 8.4.
8) Intestinal Juice- 8.0.
9) Saliva- 6.9 – 8.0.
10) Brunner’s gland secretion (duodenum)- 8.3 – 8.9.
11) RBC (cell) – 7.20.
Most alkaline fluid (Highest PH) – Brunner’s gland secretion.
Most acidic fluid (Lowest Ph) – Gastric juice.