Learning Objectives Dietary sources Daily Requirements Metabolism Important functions and Deficiency diseases

CHLORIDE

Chloride Cl At.No. 17 Atomic mass 35.5

CHLORIDE Halogen – highly reactive, high electro negativity special affinity to electropositive alkali metal to form ionic compound.

Dietary sources: Exist almost exclusively as NaCl Intake of Cl- is adequate as long as NaCl Human milk contains 11mEq/L chloride

REQUIREMENT (in mg) Infants 0 – 0.5 275 – 700 0.5 – 1.0 400 – 1200 0.5 – 1.0 400 – 1200 Children 1 – 3 500 – 1500 4 – 6 700 – 2100 7 – 10 925 – 2775 11+ 1400 – 4200 Adult 1700 – 5100

Distribution in body Whole Blood – 250 mg/dl Plasma – 375 mg/dl CSF – 440 mg/dl Cells – 190 mg/100 grams Muscles – 40 mg/100 grams

Absorption and excretion Chloride is absorbed from small intestine and Excreted through kidney. Mechanism of Chloride uptake is unclear, but it appears to depend on an exchange process with HCO3 Skin is another route of Loss---5mmole/day depends on weather Feces------5 mmoles/day Urine----100-200 mmoles/day

REGULATION Control of absorption and excretion is similar to that of Sodium Increase in blood volume decreases re-absorption of Chloride and vice versa Plasma level of Chloride varies with---- to a great extent depends on the plasma concentration of Na and HCO3

METABOLISM Any abnormality in Na metabolism will also result in derangements of chloride metabolism. When Na losses are excessive as in profuse sweating, diarrhea or endocrine disorders. There is an accompanying loss of chloride with loss of gastric juice.

FUNCTIONS Major Anion of ECF Essential in fluid balance Regulation of osmotic pressure Acid base equilibrium and formation of HCl

FUNCTIONS Human body contains about 15% chloride Highest concentration being in CSF and secretion of GIT. Lowest concentration in muscle and nerve tissue

Chloride being present in cell (RBC) as a component crosses cell membrane to establish equilibrium between cell contents and extra cellular fluid and minimize fluid shift. Chloride also enhances the ability of blood to carry large amounts of CO2 to the lungs and aids in potassium conservation.

Major Functions Maintain acid base balance Used in HCl production. Interacts with Na+ and K+.

Hypo-chloremic Alkalosis Loss of chloride exceeds that of Na causing an increase in bicarbonate and results in hypo-chloremic alkalosis.