• Potassium was discovered by Sir Humphrey Davy in 1807 at England. 

• Origin of name:     From the English word "potash" (pot ashes) and the Arabic word "qali" meaning alkali

•  The origin of the symbol K comes from the Latin word "kalium".

Potassium – major intracellular cation

Biochemical functions

 Potassium maintains intracellular osmoticPressure.

Potassium and pyruvate kinase

      Enzyme pyruvate kinase (of glycolysis) is dependent on K+ for optimal activity.

potassium

Potassium - transmission of nerve impulse.

Potassium –protein biosynthesis

ECF- potassium and cardiac activity

Dietary requirements

3-4 grams /day

Potassium rich foods

Potassium - rich sources

 Tender coconut water is a rich source of potassium

Absorption • The absorption of K+ from the gastrointestinal tract is very efficient (90%) and very little is lost through feces.

•  Patients with diarrhea, a good proportion of K+ is lost in the feces.

Plasma potassiumThe whole blood contains much higher level of K+ (50 mEq/ L)

 Predominantly an intracellular cation

Care should, therefore, be taken to avoid hemolysis of RBC for the estimation of serum K+.

Excretion

Potassium is mainly excreted through urine. 

The maintenance of body  acid-base balance influences K+ excretion. 

Aldosterone increases excretion of potassium.

Potassium disease states

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