LEC#1 WATER & SODIUM all is well and all

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1. Chemical Pathology II semester 6 Miss Saba Abbas

2. WATER Distribution of water and its regulation 40%-75% of total body weight consist of water Value declines with age and obesity Females have lower body content of water than men due to higher Fat content.

3. Function of water It acts as a solvent for all processes in the body. It helps in transportation of nutrients It determines the cell volume It removes waste products from body in the form of urine. It acts as a coolant by sweating

4. Distribution It can be located as Intracellular compartments Extracellular compartments

5. Intercellular Fluid present inside the cell is called intracellular fluid. It comprises two third of the body weight i.e 66%. It is also known as cytosol in which organelles are suspended. Cytosol together with organelles composes cytoplasm.

6. Extracellular It is the fluid present outside the cell. It comprises one third of the total body water. It is further subdivided into Intravascular Interstitial transcellular

7. Intravascular fluid The fluid which is mainly present within the blood vessels, a part of extracellular  fluid   The main intravascular fluid in mammals is blood, a complex mixture with elements of a suspension (blood cells), colloid (globulins), and solutes (glucose) and ions. The average volume of plasma in the average (70 kg) men is approximately 3.5 liters

8. Interstitial fluid The interstitial compartment also called "tissue space" surrounds tissue cells. It is filled with  interstitial fluid .  In the average (70 kg) human body, the interstitial space has approximately 10.5 litres of fluid.

9. Transcellular fluid The third extracellular compartment, the transcellular , consists of those spaces in the body where fluid does not normally collect in larger amounts.  Examples of transcellular spaces include the eye, the central nervous system, the peritoneal and  pleural  cavities, and the joint capsules. 

10. Electrolytes Electrolytes are the ions capable of carrying an electric charge. They are classified as “ANIONS” which have the negative charge and move towards the anode and “CATION” have the positive charge and move towards the cathode.

11. Functions of Electrolytes These are essential for various body processes. It helps in volume and osmotic regulation. e.g. K, Nacl It helps in myocardial contraction. e.g. Ca, Mg, K It acts as a cofactor for enzymes e.g Mg, Ca and Zn It helps in blood coagulation e.g Ca It helps in neuromuscular excitibility e.g Na, K, Ca and Mg

12. SODIUM Sodium is the most abundant cation in the ECF. It represents 90% of the extracellular cations . It determines the osmolality of the plasma. A normal plasma osmolality is Aproximately 295mmol/Kg with 270 mmol /Kg being the result of Na.

13. Regulation Of Sodium Plasma sodium depends largely on intake and excretion of water and to some extent by renal regulation of Na. There are 3 processes which are primarily important Intake of water in respose of thrust. Excretion of water effected by ADH release in response of change in blood volume and osmolality . Blood volume status which effects through aldosteron , angiotensin II and ANP ( atrial natriuretic peptide)

14. Regulation Of Sodium Kidney is capable to conserve or excrete large amount of sodium, depending on the sodium content of ECF and blood volume. 60%-75% of filtered sodium is reabsorbed in the proximal tubules.

15. Clinical application Hyponatremia Hyponatremia is defined as SODIUM serum/plasma level less than 135mmol/L. It is one of the most important electrolyte disorder. Levels less than 130 mmol /L is clinically significant.

16. CAUSES Decreased levels may be caused by Increased sodium loss Hypoaldosteronism K deficiency Diuretics use Prolonged dirrhoea and vomiting

17. CAUSES 2. Increased water retention [t he action of absorbing] Renal failure Nephrotic syndrome Liver cirrhosis Congestive heart failure Urine sodium >20mmol/ day, acute and chronic renal failure is the likely cause When urine volume <20mmol/ day,results of nephrotic syndrome and hepatic cirrhosis

18. CUASES 3. water imbalance Excess water intake Polydepsia (Excessive and constant thirst caused by disease.) CNS disorders

19. Symptoms Symptoms depends on the serum levels If the serum level is 125mmol/L, then the primary symptoms will be gastrointestinal. If levels are below 125mmol/L, then the symptoms will be Nausea, vomiting, muscular weakness, headache, lethargy and ataxia. More severe symptoms include seizures, coma and respiratory depression.

20. symptoms If levels are below 120mmol/L, then the patient will be need medical emergency.

21. Treatment It is directed at correction of condition either water loss or sodium loss. Correction too rapidly can cause cerebral myelinolysis and too slow can cause cerebral edema.

22. Hypernatremia Is an increased sodium concentration It results of excess loss of water relative to sodium loss.

23. Causes Increase water loss Decrease water intake Increase water loss Renal tabular disorders Prolonged diarrhea and sweating Severe Burn

24. Decrease water intake Older Age Infants Mental impairment Dialysis

25. Symptoms Lathergy {a pathological state of sleepiness or deep unresponsiveness and inactivity.} Irritability Seizures Altered mental status Muscle twitching Fever

26. How to determine the sodium 1. By Flame photometer 2. Atomic absorption 3. Ion selective electrode

27. THANK YOU